Otherwise its possible for an unrelated KVM_REQ_UPDATE_CLOCK (such as due to CPU
migration) to clear the bit.
Noticed by Paolo Bonzini.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
No need to check return value before breaking switch.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Return value of this function will be that of ioctl().
#include <stdio.h>
#include <linux/kvm.h>
int main () {
int fd;
fd = open ("/dev/kvm", 0);
fd = ioctl (fd, KVM_CREATE_VM, 0);
ioctl (fd, KVM_SET_TSS_ADDR, 0xfffff000);
perror ("");
return 0;
}
Output is "Operation not permitted". That's not what
we want.
Return -EINVAL in this case.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We should avoid kfree()ing error pointer in kvm_vcpu_ioctl() and
kvm_arch_vcpu_ioctl().
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
On hosts without the XSAVE support unprivileged local user can trigger
oops similar to the one below by setting X86_CR4_OSXSAVE bit in guest
cr4 register using KVM_SET_SREGS ioctl and later issuing KVM_RUN
ioctl.
invalid opcode: 0000 [#2] SMP
Modules linked in: tun ip6table_filter ip6_tables ebtable_nat ebtables
...
Pid: 24935, comm: zoog_kvm_monito Tainted: G D 3.2.0-3-686-pae
EIP: 0060:[<f8b9550c>] EFLAGS: 00210246 CPU: 0
EIP is at kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm]
EAX: 00000001 EBX: 000f387e ECX: 00000000 EDX: 00000000
ESI: 00000000 EDI: 00000000 EBP: ef5a0060 ESP: d7c63e70
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process zoog_kvm_monito (pid: 24935, ti=d7c62000 task=ed84a0c0
task.ti=d7c62000)
Stack:
00000001 f70a1200 f8b940a9 ef5a0060 00000000 00200202 f8769009 00000000
ef5a0060 000f387e eda5c020 8722f9c8 00015bae 00000000 ed84a0c0 ed84a0c0
c12bf02d 0000ae80 ef7f8740 fffffffb f359b740 ef5a0060 f8b85dc1 0000ae80
Call Trace:
[<f8b940a9>] ? kvm_arch_vcpu_ioctl_set_sregs+0x2fe/0x308 [kvm]
...
[<c12bfb44>] ? syscall_call+0x7/0xb
Code: 89 e8 e8 14 ee ff ff ba 00 00 04 00 89 e8 e8 98 48 ff ff 85 c0 74
1e 83 7d 48 00 75 18 8b 85 08 07 00 00 31 c9 8b 95 0c 07 00 00 <0f> 01
d1 c7 45 48 01 00 00 00 c7 45 1c 01 00 00 00 0f ae f0 89
EIP: [<f8b9550c>] kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] SS:ESP
0068:d7c63e70
QEMU first retrieves the supported features via KVM_GET_SUPPORTED_CPUID
and then sets them later. So guest's X86_FEATURE_XSAVE should be masked
out on hosts without X86_FEATURE_XSAVE, making kvm_set_cr4 with
X86_CR4_OSXSAVE fail. Userspaces that allow specifying guest cpuid with
X86_FEATURE_XSAVE even on hosts that do not support it, might be
susceptible to this attack from inside the guest as well.
Allow setting X86_CR4_OSXSAVE bit only if host has XSAVE support.
Signed-off-by: Petr Matousek <pmatouse@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
After commit b3356bf0db (KVM: emulator: optimize "rep ins" handling),
the pieces of io data can be collected and write them to the guest memory
or MMIO together
Unfortunately, kvm splits the mmio access into 8 bytes and store them to
vcpu->mmio_fragments. If the guest uses "rep ins" to move large data, it
will cause vcpu->mmio_fragments overflow
The bug can be exposed by isapc (-M isapc):
[23154.818733] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[ ......]
[23154.858083] Call Trace:
[23154.859874] [<ffffffffa04f0e17>] kvm_get_cr8+0x1d/0x28 [kvm]
[23154.861677] [<ffffffffa04fa6d4>] kvm_arch_vcpu_ioctl_run+0xcda/0xe45 [kvm]
[23154.863604] [<ffffffffa04f5a1a>] ? kvm_arch_vcpu_load+0x17b/0x180 [kvm]
Actually, we can use one mmio_fragment to store a large mmio access then
split it when we pass the mmio-exit-info to userspace. After that, we only
need two entries to store mmio info for the cross-mmio pages access
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch filters noslot pfn out from error pfns based on Marcelo comment:
noslot pfn is not a error pfn
After this patch,
- is_noslot_pfn indicates that the gfn is not in slot
- is_error_pfn indicates that the gfn is in slot but the error is occurred
when translate the gfn to pfn
- is_error_noslot_pfn indicates that the pfn either it is error pfns or it
is noslot pfn
And is_invalid_pfn can be removed, it makes the code more clean
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
There are no external callers of this function as there is no concept of
resetting a vcpu from generic code.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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Merge tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Avi Kivity:
"Highlights of the changes for this release include support for vfio
level triggered interrupts, improved big real mode support on older
Intels, a streamlines guest page table walker, guest APIC speedups,
PIO optimizations, better overcommit handling, and read-only memory."
* tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (138 commits)
KVM: s390: Fix vcpu_load handling in interrupt code
KVM: x86: Fix guest debug across vcpu INIT reset
KVM: Add resampling irqfds for level triggered interrupts
KVM: optimize apic interrupt delivery
KVM: MMU: Eliminate pointless temporary 'ac'
KVM: MMU: Avoid access/dirty update loop if all is well
KVM: MMU: Eliminate eperm temporary
KVM: MMU: Optimize is_last_gpte()
KVM: MMU: Simplify walk_addr_generic() loop
KVM: MMU: Optimize pte permission checks
KVM: MMU: Update accessed and dirty bits after guest pagetable walk
KVM: MMU: Move gpte_access() out of paging_tmpl.h
KVM: MMU: Optimize gpte_access() slightly
KVM: MMU: Push clean gpte write protection out of gpte_access()
KVM: clarify kvmclock documentation
KVM: make processes waiting on vcpu mutex killable
KVM: SVM: Make use of asm.h
KVM: VMX: Make use of asm.h
KVM: VMX: Make lto-friendly
KVM: x86: lapic: Clean up find_highest_vector() and count_vectors()
...
Conflicts:
arch/s390/include/asm/processor.h
arch/x86/kvm/i8259.c
Pull x86/fpu update from Ingo Molnar:
"The biggest change is the addition of the non-lazy (eager) FPU saving
support model and enabling it on CPUs with optimized xsaveopt/xrstor
FPU state saving instructions.
There are also various Sparse fixes"
Fix up trivial add-add conflict in arch/x86/kernel/traps.c
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, kvm: fix kvm's usage of kernel_fpu_begin/end()
x86, fpu: remove cpu_has_xmm check in the fx_finit()
x86, fpu: make eagerfpu= boot param tri-state
x86, fpu: enable eagerfpu by default for xsaveopt
x86, fpu: decouple non-lazy/eager fpu restore from xsave
x86, fpu: use non-lazy fpu restore for processors supporting xsave
lguest, x86: handle guest TS bit for lazy/non-lazy fpu host models
x86, fpu: always use kernel_fpu_begin/end() for in-kernel FPU usage
x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu()
x86, fpu: remove unnecessary user_fpu_end() in save_xstate_sig()
x86, fpu: drop_fpu() before restoring new state from sigframe
x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels
x86, fpu: Consolidate inline asm routines for saving/restoring fpu state
x86, signal: Cleanup ifdefs and is_ia32, is_x32
If we reset a vcpu on INIT, we so far overwrote dr7 as provided by
KVM_SET_GUEST_DEBUG, and we also cleared switch_db_regs unconditionally.
Fix this by saving the dr7 used for guest debugging and calculating the
effective register value as well as switch_db_regs on any potential
change. This will change to focus of the set_guest_debug vendor op to
update_dp_bp_intercept.
Found while trying to stop on start_secondary.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
To emulate level triggered interrupts, add a resample option to
KVM_IRQFD. When specified, a new resamplefd is provided that notifies
the user when the irqchip has been resampled by the VM. This may, for
instance, indicate an EOI. Also in this mode, posting of an interrupt
through an irqfd only asserts the interrupt. On resampling, the
interrupt is automatically de-asserted prior to user notification.
This enables level triggered interrupts to be posted and re-enabled
from vfio with no userspace intervention.
All resampling irqfds can make use of a single irq source ID, so we
reserve a new one for this interface.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Preemption is disabled between kernel_fpu_begin/end() and as such
it is not a good idea to use these routines in kvm_load/put_guest_fpu()
which can be very far apart.
kvm_load/put_guest_fpu() routines are already called with
preemption disabled and KVM already uses the preempt notifier to save
the guest fpu state using kvm_put_guest_fpu().
So introduce __kernel_fpu_begin/end() routines which don't touch
preemption and use them instead of kernel_fpu_begin/end()
for KVM's use model of saving/restoring guest FPU state.
Also with this change (and with eagerFPU model), fix the host cr0.TS vm-exit
state in the case of VMX. For eagerFPU case, host cr0.TS is always clear.
So no need to worry about it. For the traditional lazyFPU restore case,
change the cr0.TS bit for the host state during vm-exit to be always clear
and cr0.TS bit is set in the __vmx_load_host_state() when the FPU
(guest FPU or the host task's FPU) state is not active. This ensures
that the host/guest FPU state is properly saved, restored
during context-switch and with interrupts (using irq_fpu_usable()) not
stomping on the active FPU state.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1348164109.26695.338.camel@sbsiddha-desk.sc.intel.com
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Most interrupt are delivered to only one vcpu. Use pre-build tables to
find interrupt destination instead of looping through all vcpus. In case
of logical mode loop only through vcpus in a logical cluster irq is sent
to.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
walk_addr_generic() permission checks are a maze of branchy code, which is
performed four times per lookup. It depends on the type of access, efer.nxe,
cr0.wp, cr4.smep, and in the near future, cr4.smap.
Optimize this away by precalculating all variants and storing them in a
bitmap. The bitmap is recalculated when rarely-changing variables change
(cr0, cr4) and is indexed by the often-changing variables (page fault error
code, pte access permissions).
The permission check is moved to the end of the loop, otherwise an SMEP
fault could be reported as a false positive, when PDE.U=1 but PTE.U=0.
Noted by Xiao Guangrong.
The result is short, branch-free code.
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm's guest fpu save/restore should be wrapped around
kernel_fpu_begin/end(). This will avoid for example taking a DNA
in kvm_load_guest_fpu() when it tries to load the fpu immediately
after doing unlazy_fpu() on the host side.
More importantly this will prevent the host process fpu from being
corrupted.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1345842782-24175-4-git-send-email-suresh.b.siddha@intel.com
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
vcpu mutex can be held for unlimited time so
taking it with mutex_lock on an ioctl is wrong:
one process could be passed a vcpu fd and
call this ioctl on the vcpu used by another process,
it will then be unkillable until the owner exits.
Call mutex_lock_killable instead and return status.
Note: mutex_lock_interruptible would be even nicer,
but I am not sure all users are prepared to handle EINTR
from these ioctls. They might misinterpret it as an error.
Cleanup paths expect a vcpu that can't be used by
any userspace so this will always succeed - catch bugs
by calling BUG_ON.
Catch callers that don't check return state by adding
__must_check.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This bug was triggered:
[ 4220.198458] BUG: unable to handle kernel paging request at fffffffffffffffe
[ 4220.203907] IP: [<ffffffff81104d85>] put_page+0xf/0x34
......
[ 4220.237326] Call Trace:
[ 4220.237361] [<ffffffffa03830d0>] kvm_arch_destroy_vm+0xf9/0x101 [kvm]
[ 4220.237382] [<ffffffffa036fe53>] kvm_put_kvm+0xcc/0x127 [kvm]
[ 4220.237401] [<ffffffffa03702bc>] kvm_vcpu_release+0x18/0x1c [kvm]
[ 4220.237407] [<ffffffff81145425>] __fput+0x111/0x1ed
[ 4220.237411] [<ffffffff8114550f>] ____fput+0xe/0x10
[ 4220.237418] [<ffffffff81063511>] task_work_run+0x5d/0x88
[ 4220.237424] [<ffffffff8104c3f7>] do_exit+0x2bf/0x7ca
The test case:
printf(fmt, ##args); \
exit(-1);} while (0)
static int create_vm(void)
{
int sys_fd, vm_fd;
sys_fd = open("/dev/kvm", O_RDWR);
if (sys_fd < 0)
die("open /dev/kvm fail.\n");
vm_fd = ioctl(sys_fd, KVM_CREATE_VM, 0);
if (vm_fd < 0)
die("KVM_CREATE_VM fail.\n");
return vm_fd;
}
static int create_vcpu(int vm_fd)
{
int vcpu_fd;
vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0);
if (vcpu_fd < 0)
die("KVM_CREATE_VCPU ioctl.\n");
printf("Create vcpu.\n");
return vcpu_fd;
}
static void *vcpu_thread(void *arg)
{
int vm_fd = (int)(long)arg;
create_vcpu(vm_fd);
return NULL;
}
int main(int argc, char *argv[])
{
pthread_t thread;
int vm_fd;
(void)argc;
(void)argv;
vm_fd = create_vm();
pthread_create(&thread, NULL, vcpu_thread, (void *)(long)vm_fd);
printf("Exit.\n");
return 0;
}
It caused by release kvm->arch.ept_identity_map_addr which is the
error page.
The parent thread can send KILL signal to the vcpu thread when it was
exiting which stops faulting pages and potentially allocating memory.
So gfn_to_pfn/gfn_to_page may fail at this time
Fixed by checking the page before it is used
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
interrupt_bitmap is KVM_NR_INTERRUPTS bits in size,
so just use that instead of hard-coded constants
and math.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Current code assumes that IO exit was due to instruction emulation
and handles execution back to emulator directly. This patch adds new
userspace IO exit completion callback that can be set by any other code
that caused IO exit to userspace.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Other arches do not need this.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
v2: fix incorrect deletion of mmio sptes on gpa move (noticed by Takuya)
Signed-off-by: Avi Kivity <avi@redhat.com>
Introducing kvm_arch_flush_shadow_memslot, to invalidate the
translations of a single memory slot.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
We never change emulate_ops[] at runtime so it should be r/o.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of populating the entire register file, read in registers
as they are accessed, and write back only the modified ones. This
saves a VMREAD and VMWRITE on Intel (for rsp, since it is not usually
used during emulation), and a two 128-byte copies for the registers.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM_GET_MSR was missing support for PV EOI,
which is needed for migration.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In current code, if we map a readonly memory space from host to guest
and the page is not currently mapped in the host, we will get a fault
pfn and async is not allowed, then the vm will crash
We introduce readonly memory region to map ROM/ROMD to the guest, read access
is happy for readonly memslot, write access on readonly memslot will cause
KVM_EXIT_MMIO exit
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently, we reexecute all unhandleable instructions if they do not
access on the mmio, however, it can not work if host map the readonly
memory to guest. If the instruction try to write this kind of memory,
it will fault again when guest retry it, then we will goto a infinite
loop: retry instruction -> write #PF -> emulation fail ->
retry instruction -> ...
Fix it by retrying the instruction only when it faults on the writable
memory
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm_guest_time_update unconditionally clears hv_clock.flags field,
so the notification never reaches the guest.
Fix it by allowing PVCLOCK_GUEST_STOPPED to passthrough.
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
For apic_set_spiv() to track APIC SW state correctly it needs to see
previous and next values of the spurious vector register, but currently
memset() overwrite the old value before apic_set_spiv() get a chance to
do tracking. Fix it by calling apic_set_spiv() before overwriting old
value.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Usually all vcpus have local apic pointer initialized, so the check may
be completely skipped.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Usually all APICs are HW enabled so the check can be optimized out.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm_get_apic_base() needlessly checks irqchip_in_kernel although it does
the same no matter what result of the check is. kvm_set_apic_base() also
checks for irqchip_in_kernel, but kvm_lapic_set_base() can handle this
case.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
After commit a2766325cf, the error page is replaced by the
error code, it need not be released anymore
[ The patch has been compiling tested for powerpc ]
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Two reasons:
- x86 can integrate rmap and rmap_pde and remove heuristics in
__gfn_to_rmap().
- Some architectures do not need rmap.
Since rmap is one of the most memory consuming stuff in KVM, ppc'd
better restrict the allocation to Book3S HV.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead, check npages consistently. This helps to make rmap
architecture specific in a later patch.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
When MSR_KVM_PV_EOI_EN was added to msrs_to_save array
KVM_SAVE_MSRS_BEGIN was not updated accordingly.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
- bring back critical fixes (esp. aa67f6096c)
- provide an updated base for development
* upstream: (4334 commits)
missed mnt_drop_write() in do_dentry_open()
UBIFS: nuke pdflush from comments
gfs2: nuke pdflush from comments
drbd: nuke pdflush from comments
nilfs2: nuke write_super from comments
hfs: nuke write_super from comments
vfs: nuke pdflush from comments
jbd/jbd2: nuke write_super from comments
btrfs: nuke pdflush from comments
btrfs: nuke write_super from comments
ext4: nuke pdflush from comments
ext4: nuke write_super from comments
ext3: nuke write_super from comments
Documentation: fix the VM knobs descritpion WRT pdflush
Documentation: get rid of write_super
vfs: kill write_super and sync_supers
ACPI processor: Fix tick_broadcast_mask online/offline regression
ACPI: Only count valid srat memory structures
ACPI: Untangle a return statement for better readability
Linux 3.6-rc1
...
Signed-off-by: Avi Kivity <avi@redhat.com>
When MSR_KVM_PV_EOI_EN was added to msrs_to_save array
KVM_SAVE_MSRS_BEGIN was not updated accordingly.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When a guest migrates to a new host, the system time difference from the
previous host is used in the updates to the kvmclock system time visible
to the guest, resulting in a continuation of correct kvmclock based guest
timekeeping.
The wall clock component of the kvmclock provided time is currently not
updated with this same time offset. Since the Linux guest caches the
wall clock based time, this discrepency is not noticed until the guest is
rebooted. After reboot the guest's time calculations are off.
This patch adjusts the wall clock by the kvmclock_offset, resulting in
correct guest time after a reboot.
Cc: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
One structure nests inside the other, providing no value at all.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Handle KVM_IRQ_LINE and KVM_IRQ_LINE_STATUS in the generic
kvm_vm_ioctl() function and call into kvm_vm_ioctl_irq_line().
This is even more relevant when KVM/ARM also uses this ioctl.
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This makes it possible to loop over rmap_pde arrays in the same way as
we do over rmap so that we can optimize kvm_handle_hva_range() easily in
the following patch.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch handles PCID/INVPCID for guests.
Process-context identifiers (PCIDs) are a facility by which a logical processor
may cache information for multiple linear-address spaces so that the processor
may retain cached information when software switches to a different linear
address space. Refer to section 4.10.1 in IA32 Intel Software Developer's Manual
Volume 3A for details.
For guests with EPT, the PCID feature is enabled and INVPCID behaves as running
natively.
For guests without EPT, the PCID feature is disabled and INVPCID triggers #UD.
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of getting an exact leaf, follow the spec and fall back to the last
main leaf instead. This lets us easily emulate the cpuid instruction in the
emulator.
Signed-off-by: Avi Kivity <avi@redhat.com>
Implementation of PV EOI using shared memory.
This reduces the number of exits an interrupt
causes as much as by half.
The idea is simple: there's a bit, per APIC, in guest memory,
that tells the guest that it does not need EOI.
We set it before injecting an interrupt and clear
before injecting a nested one. Guest tests it using
a test and clear operation - this is necessary
so that host can detect interrupt nesting -
and if set, it can skip the EOI MSR.
There's a new MSR to set the address of said register
in guest memory. Otherwise not much changed:
- Guest EOI is not required
- Register is tested & ISR is automatically cleared on exit
For testing results see description of previous patch
'kvm_para: guest side for eoi avoidance'.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Each time we need to cancel injection we invoke same code
(cancel_injection callback). Move it towards the end of function using
the familiar goto on error pattern.
Will make it easier to do more cleanups for PV EOI.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Commit eb0dc6d0368072236dcd086d7fdc17fd3c4574d4 introduced apic
attention bitmask but kvm still syncs lapic unconditionally.
As that commit suggested and in anticipation of adding more attention
bits, only sync lapic if(apic_attention).
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The following commit did not care about the error handling path:
commit c1a7b32a14
KVM: Avoid wasting pages for small lpage_info arrays
If memory allocation fails, vfree() will be called with the address
returned by kzalloc(). This patch fixes this issue.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduces a couple of print functions, which are essentially wrappers
around standard printk functions, with a KVM: prefix.
Functions introduced or modified are:
- kvm_err(fmt, ...)
- kvm_info(fmt, ...)
- kvm_debug(fmt, ...)
- kvm_pr_unimpl(fmt, ...)
- pr_unimpl(vcpu, fmt, ...) -> vcpu_unimpl(vcpu, fmt, ...)
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
lpage_info is created for each large level even when the memory slot is
not for RAM. This means that when we add one slot for a PCI device, we
end up allocating at least KVM_NR_PAGE_SIZES - 1 pages by vmalloc().
To make things worse, there is an increasing number of devices which
would result in more pages being wasted this way.
This patch mitigates this problem by using kvm_kvzalloc().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Pull KVM changes from Avi Kivity:
"Changes include additional instruction emulation, page-crossing MMIO,
faster dirty logging, preventing the watchdog from killing a stopped
guest, module autoload, a new MSI ABI, and some minor optimizations
and fixes. Outside x86 we have a small s390 and a very large ppc
update.
Regarding the new (for kvm) rebaseless workflow, some of the patches
that were merged before we switch trees had to be rebased, while
others are true pulls. In either case the signoffs should be correct
now."
Fix up trivial conflicts in Documentation/feature-removal-schedule.txt
arch/powerpc/kvm/book3s_segment.S and arch/x86/include/asm/kvm_para.h.
I suspect the kvm_para.h resolution ends up doing the "do I have cpuid"
check effectively twice (it was done differently in two different
commits), but better safe than sorry ;)
* 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (125 commits)
KVM: make asm-generic/kvm_para.h have an ifdef __KERNEL__ block
KVM: s390: onereg for timer related registers
KVM: s390: epoch difference and TOD programmable field
KVM: s390: KVM_GET/SET_ONEREG for s390
KVM: s390: add capability indicating COW support
KVM: Fix mmu_reload() clash with nested vmx event injection
KVM: MMU: Don't use RCU for lockless shadow walking
KVM: VMX: Optimize %ds, %es reload
KVM: VMX: Fix %ds/%es clobber
KVM: x86 emulator: convert bsf/bsr instructions to emulate_2op_SrcV_nobyte()
KVM: VMX: unlike vmcs on fail path
KVM: PPC: Emulator: clean up SPR reads and writes
KVM: PPC: Emulator: clean up instruction parsing
kvm/powerpc: Add new ioctl to retreive server MMU infos
kvm/book3s: Make kernel emulated H_PUT_TCE available for "PR" KVM
KVM: PPC: bookehv: Fix r8/r13 storing in level exception handler
KVM: PPC: Book3S: Enable IRQs during exit handling
KVM: PPC: Fix PR KVM on POWER7 bare metal
KVM: PPC: Fix stbux emulation
KVM: PPC: bookehv: Use lwz/stw instead of PPC_LL/PPC_STL for 32-bit fields
...
Currently the inject_pending_event() call during guest entry happens after
kvm_mmu_reload(). This is for historical reasons - we used to
inject_pending_event() in atomic context, while kvm_mmu_reload() needs task
context.
A problem is that nested vmx can cause the mmu context to be reset, if event
injection is intercepted and causes a #VMEXIT instead (the #VMEXIT resets
CR0/CR3/CR4). If this happens, we end up with invalid root_hpa, and since
kvm_mmu_reload() has already run, no one will fix it and we end up entering
the guest this way.
Fix by reordering event injection to be before kvm_mmu_reload(). Use
->cancel_injection() to undo if kvm_mmu_reload() fails.
https://bugzilla.kernel.org/show_bug.cgi?id=42980
Reported-by: Luke-Jr <luke-jr+linuxbugs@utopios.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If vcpu executes hlt instruction while async PF is waiting to be delivered
vcpu can block and deliver async PF only after another even wakes it
up. This happens because kvm_check_async_pf_completion() will remove
completion event from vcpu->async_pf.done before entering kvm_vcpu_block()
and this will make kvm_arch_vcpu_runnable() return false. The solution
is to make vcpu runnable when processing completion.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.
This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c. But that way we don't have
to export our internal do_mmap_pgoff() function.
Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead. We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Like the vm_brk() function, this is the same as "do_munmap()", except it
does the VM locking for the caller.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MMIO that are split across a page boundary are currently broken - the
code does not expect to be aborted by the exit to userspace for the
first MMIO fragment.
This patch fixes the problem by generalizing the current code for handling
16-byte MMIOs to handle a number of "fragments", and changes the MMIO
code to create those fragments.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We have seen some problems of the current implementation of
get_dirty_log() which uses synchronize_srcu_expedited() for updating
dirty bitmaps; e.g. it is noticeable that this sometimes gives us ms
order of latency when we use VGA displays.
Furthermore the recent discussion on the following thread
"srcu: Implement call_srcu()"
http://lkml.org/lkml/2012/1/31/211
also motivated us to implement get_dirty_log() without SRCU.
This patch achieves this goal without sacrificing the performance of
both VGA and live migration: in practice the new code is much faster
than the old one unless we have too many dirty pages.
Implementation:
The key part of the implementation is the use of xchg() operation for
clearing dirty bits atomically. Since this allows us to update only
BITS_PER_LONG pages at once, we need to iterate over the dirty bitmap
until every dirty bit is cleared again for the next call.
Although some people may worry about the problem of using the atomic
memory instruction many times to the concurrently accessible bitmap,
it is usually accessed with mmu_lock held and we rarely see concurrent
accesses: so what we need to care about is the pure xchg() overheads.
Another point to note is that we do not use for_each_set_bit() to check
which ones in each BITS_PER_LONG pages are actually dirty. Instead we
simply use __ffs() in a loop. This is much faster than repeatedly call
find_next_bit().
Performance:
The dirty-log-perf unit test showed nice improvements, some times faster
than before, except for some extreme cases; for such cases the speed of
getting dirty page information is much faster than we process it in the
userspace.
For real workloads, both VGA and live migration, we have observed pure
improvements: when the guest was reading a file during live migration,
we originally saw a few ms of latency, but with the new method the
latency was less than 200us.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Dropped such mappings when we enabled dirty logging and we will never
create new ones until we stop the logging.
For this we introduce a new function which can be used to write protect
a range of PT level pages: although we do not need to care about a range
of pages at this point, the following patch will need this feature to
optimize the write protection of many pages.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Now that we have a flag that will tell the guest it was suspended, create an
interface for that communication using a KVM ioctl.
Signed-off-by: Eric B Munson <emunson@mgebm.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The kvm_vcpu_kick function performs roughly the same funcitonality on
most all architectures, so we shouldn't have separate copies.
PowerPC keeps a pointer to interchanging waitqueues on the vcpu_arch
structure and to accomodate this special need a
__KVM_HAVE_ARCH_VCPU_GET_WQ define and accompanying function
kvm_arch_vcpu_wq have been defined. For all other architectures this
is a generic inline that just returns &vcpu->wq;
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Pull kvm updates from Avi Kivity:
"Changes include timekeeping improvements, support for assigning host
PCI devices that share interrupt lines, s390 user-controlled guests, a
large ppc update, and random fixes."
This is with the sign-off's fixed, hopefully next merge window we won't
have rebased commits.
* 'kvm-updates/3.4' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (130 commits)
KVM: Convert intx_mask_lock to spin lock
KVM: x86: fix kvm_write_tsc() TSC matching thinko
x86: kvmclock: abstract save/restore sched_clock_state
KVM: nVMX: Fix erroneous exception bitmap check
KVM: Ignore the writes to MSR_K7_HWCR(3)
KVM: MMU: make use of ->root_level in reset_rsvds_bits_mask
KVM: PMU: add proper support for fixed counter 2
KVM: PMU: Fix raw event check
KVM: PMU: warn when pin control is set in eventsel msr
KVM: VMX: Fix delayed load of shared MSRs
KVM: use correct tlbs dirty type in cmpxchg
KVM: Allow host IRQ sharing for assigned PCI 2.3 devices
KVM: Ensure all vcpus are consistent with in-kernel irqchip settings
KVM: x86 emulator: Allow PM/VM86 switch during task switch
KVM: SVM: Fix CPL updates
KVM: x86 emulator: VM86 segments must have DPL 3
KVM: x86 emulator: Fix task switch privilege checks
arch/powerpc/kvm/book3s_hv.c: included linux/sched.h twice
KVM: x86 emulator: correctly mask pmc index bits in RDPMC instruction emulation
KVM: mmu_notifier: Flush TLBs before releasing mmu_lock
...
Pull x86/fpu changes from Ingo Molnar.
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
i387: Split up <asm/i387.h> into exported and internal interfaces
i387: Uninline the generic FP helpers that we expose to kernel modules
kvm_write_tsc() converts from guest TSC to microseconds, not nanoseconds
as intended. The result is that the window for matching is 1000 seconds,
not 1 second.
Microsecond precision is enough for checking whether the TSC write delta
is within the heuristic values, so use it instead of nanoseconds.
Noted by Avi Kivity.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When CPUID Fn8000_0001_EAX reports 0x00100f22 Windows 7 x64 guest
tries to set bit 3 in MSRC001_0015 in nt!KiDisableCacheErrataSource
and fails. This patch will ignore this step and allow things to move
on without having to fake CPUID value.
Signed-off-by: Nicolae Mogoreanu <mogoreanu@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
PCI 2.3 allows to generically disable IRQ sources at device level. This
enables us to share legacy IRQs of such devices with other host devices
when passing them to a guest.
The new IRQ sharing feature introduced here is optional, user space has
to request it explicitly. Moreover, user space can inform us about its
view of PCI_COMMAND_INTX_DISABLE so that we can avoid unmasking the
interrupt and signaling it if the guest masked it via the virtualized
PCI config space.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If some vcpus are created before KVM_CREATE_IRQCHIP, then
irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading
to potential NULL pointer dereferences.
Fix by:
- ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called
- ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP
This is somewhat long winded because vcpu->arch.apic is created without
kvm->lock held.
Based on earlier patch by Michael Ellerman.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Avi Kivity <avi@redhat.com>
Task switches can switch between Protected Mode and VM86. The current
mode must be updated during the task switch emulation so that the new
segment selectors are interpreted correctly.
In order to let privilege checks succeed, rflags needs to be updated in
the vcpu struct as this causes a CPL update.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently, all task switches check privileges against the DPL of the
TSS. This is only correct for jmp/call to a TSS. If a task gate is used,
the DPL of this take gate is used for the check instead. Exceptions,
external interrupts and iret shouldn't perform any check.
[avi: kill kvm-kmod remnants]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Some members of kvm_memory_slot are not used by every architecture.
This patch is the first step to make this difference clear by
introducing kvm_memory_slot::arch; lpage_info is moved into it.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch fixes a race introduced by:
commit 95d4c16ce7
KVM: Optimize dirty logging by rmap_write_protect()
During protecting pages for dirty logging, other threads may also try
to protect a page in mmu_sync_children() or kvm_mmu_get_page().
In such a case, because get_dirty_log releases mmu_lock before flushing
TLB's, the following race condition can happen:
A (get_dirty_log) B (another thread)
lock(mmu_lock)
clear pte.w
unlock(mmu_lock)
lock(mmu_lock)
pte.w is already cleared
unlock(mmu_lock)
skip TLB flush
return
...
TLB flush
Though thread B assumes the page has already been protected when it
returns, the remaining TLB entry will break that assumption.
This patch fixes this problem by making get_dirty_log hold the mmu_lock
until it flushes the TLB's.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This allows us to track the original nanosecond and counter values
at each phase of TSC writing by the guest. This gets us perfect
offset matching for stable TSC systems, and perfect software
computed TSC matching for machines with unstable TSC.
Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
During a host suspend, TSC may go backwards, which KVM interprets
as an unstable TSC. Technically, KVM should not be marking the
TSC unstable, which causes the TSC clocksource to go bad, but we
need to be adjusting the TSC offsets in such a case.
Dealing with this issue is a little tricky as the only place we
can reliably do it is before much of the timekeeping infrastructure
is up and running. On top of this, we are not in a KVM thread
context, so we may not be able to safely access VCPU fields.
Instead, we compute our best known hardware offset at power-up and
stash it to be applied to all VCPUs when they actually start running.
Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Redefine the API to take a parameter indicating whether an
adjustment is in host or guest cycles.
Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The variable last_host_tsc was removed from upstream code. I am adding
it back for two reasons. First, it is unnecessary to use guest TSC
computation to conclude information about the host TSC. The guest may
set the TSC backwards (this case handled by the previous patch), but
the computation of guest TSC (and fetching an MSR) is significanlty more
work and complexity than simply reading the hardware counter. In addition,
we don't actually need the guest TSC for any part of the computation,
by always recomputing the offset, we can eliminate the need to deal with
the current offset and any scaling factors that may apply.
The second reason is that later on, we are going to be using the host
TSC value to restore TSC offsets after a host S4 suspend, so we need to
be reading the host values, not the guest values here.
Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The variable last_guest_tsc was being used as an ad-hoc indicator
that guest TSC has been initialized and recorded correctly. However,
it may not have been, it could be that guest TSC has been set to some
large value, the back to a small value (by, say, a software reboot).
This defeats the logic and causes KVM to falsely assume that the
guest TSC has gone backwards, marking the host TSC unstable, which
is undesirable behavior.
In addition, rather than try to compute an offset adjustment for the
TSC on unstable platforms, just recompute the whole offset. This
allows us to get rid of one callsite for adjust_tsc_offset, which
is problematic because the units it takes are in guest units, but
here, the computation was originally being done in host units.
Doing this, and also recording last_guest_tsc when the TSC is written
allow us to remove the tricky logic which depended on last_guest_tsc
being zero to indicate a reset of uninitialized value.
Instead, we now have the guarantee that the guest TSC offset is
always at least something which will get us last_guest_tsc.
Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently, when the TSC is written by the guest, the variable
ns is updated to force the current write to appear to have taken
place at the time of the first write in this sync phase. This
leaves a cliff at the end of the match window where updates will
fall of the end. There are two scenarios where this can be a
problem in practe - first, on a system with a large number of
VCPUs, the sync period may last for an extended period of time.
The second way this can happen is if the VM reboots very rapidly
and we catch a VCPU TSC synchronization just around the edge.
We may be unaware of the reboot, and thus the first VCPU might
synchronize with an old set of the timer (at, say 0.97 seconds
ago, when first powered on). The second VCPU can come in 0.04
seconds later to try to synchronize, but it misses the window
because it is just over the threshold.
Instead, stop doing this artificial setback of the ns variable
and just update it with every write of the TSC.
It may be observed that doing so causes values computed by
compute_guest_tsc to diverge slightly across CPUs - note that
the last_tsc_ns and last_tsc_write variable are used here, and
now they last_tsc_ns will be different for each VCPU, reflecting
the actual time of the update.
However, compute_guest_tsc is used only for guests which already
have TSC stability issues, and further, note that the previous
patch has caused last_tsc_write to be incremented by the difference
in nanoseconds, converted back into guest cycles. As such, only
boundary rounding errors should be visible, which given the
resolution in nanoseconds, is going to only be a few cycles and
only visible in cross-CPU consistency tests. The problem can be
fixed by adding a new set of variables to track the start offset
and start write value for the current sync cycle.
Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
There are a few improvements that can be made to the TSC offset
matching code. First, we don't need to call the 128-bit multiply
(especially on a constant number), the code works much nicer to
do computation in nanosecond units.
Second, the way everything is setup with software TSC rate scaling,
we currently have per-cpu rates. Obviously this isn't too desirable
to use in practice, but if for some reason we do change the rate of
all VCPUs at runtime, then reset the TSCs, we will only want to
match offsets for VCPUs running at the same rate.
Finally, for the case where we have an unstable host TSC, but
rate scaling is being done in hardware, we should call the platform
code to compute the TSC offset, so the math is reorganized to recompute
the base instead, then transform the base into an offset using the
existing API.
[avi: fix 64-bit division on i386]
Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM: Fix 64-bit division in kvm_write_tsc()
Breaks i386 build.
Signed-off-by: Avi Kivity <avi@redhat.com>
This requires some restructuring; rather than use 'virtual_tsc_khz'
to indicate whether hardware rate scaling is in effect, we consider
each VCPU to always have a virtual TSC rate. Instead, there is new
logic above the vendor-specific hardware scaling that decides whether
it is even necessary to use and updates all rate variables used by
common code. This means we can simply query the virtual rate at
any point, which is needed for software rate scaling.
There is also now a threshold added to the TSC rate scaling; minor
differences and variations of measured TSC rate can accidentally
provoke rate scaling to be used when it is not needed. Instead,
we have a tolerance variable called tsc_tolerance_ppm, which is
the maximum variation from user requested rate at which scaling
will be used. The default is 250ppm, which is the half the
threshold for NTP adjustment, allowing for some hardware variation.
In the event that hardware rate scaling is not available, we can
kludge a bit by forcing TSC catchup to turn on when a faster than
hardware speed has been requested, but there is nothing available
yet for the reverse case; this requires a trap and emulate software
implementation for RDTSC, which is still forthcoming.
[avi: fix 64-bit division on i386]
Signed-off-by: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
In some cases guests should not provide workarounds for errata even when the
physical processor is affected. For example, because of erratum 400 on family
10h processors a Linux guest will read an MSR (resulting in VMEXIT) before
going to idle in order to avoid getting stuck in a non-C0 state. This is not
necessary: HLT and IO instructions are intercepted and therefore there is no
reason for erratum 400 workaround in the guest.
This patch allows us to present a guest with certain errata as fixed,
regardless of the state of actual hardware.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch exports the s390 SIE hardware control block to userspace
via the mapping of the vcpu file descriptor. In order to do so,
a new arch callback named kvm_arch_vcpu_fault is introduced for all
architectures. It allows to map architecture specific pages.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces a new config option for user controlled kernel
virtual machines. It introduces a parameter to KVM_CREATE_VM that
allows to set bits that alter the capabilities of the newly created
virtual machine.
The parameter is passed to kvm_arch_init_vm for all architectures.
The only valid modifier bit for now is KVM_VM_S390_UCONTROL.
This requires CAP_SYS_ADMIN privileges and creates a user controlled
virtual machine on s390 architectures.
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
While various modules include <asm/i387.h> to get access to things we
actually *intend* for them to use, most of that header file was really
pretty low-level internal stuff that we really don't want to expose to
others.
So split the header file into two: the small exported interfaces remain
in <asm/i387.h>, while the internal definitions that are only used by
core architecture code are now in <asm/fpu-internal.h>.
The guiding principle for this was to expose functions that we export to
modules, and leave them in <asm/i387.h>, while stuff that is used by
task switching or was marked GPL-only is in <asm/fpu-internal.h>.
The fpu-internal.h file could be further split up too, especially since
arch/x86/kvm/ uses some of the remaining stuff for its module. But that
kvm usage should probably be abstracted out a bit, and at least now the
internal FPU accessor functions are much more contained. Even if it
isn't perhaps as contained as it _could_ be.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1202211340330.5354@i5.linux-foundation.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Return to behaviour perf MSR had before introducing vPMU in case vPMU
is disabled. Some guests access those registers unconditionally and do
not expect it to fail.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In order to be able to proceed checks on CPU-specific properties
within the emulator, function "get_cpuid" is introduced.
With "get_cpuid" it is possible to virtually call the guests
"cpuid"-opcode without changing the VM's context.
[mtosatti: cleanup/beautify code]
Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
module_param(bool) used to counter-intuitively take an int. In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.
It's time to remove the int/unsigned int option. For this version
it'll simply give a warning, but it'll break next kernel version.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add a helper function that emulates the RDPMC instruction operation.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Use perf_events to emulate an architectural PMU, version 2.
Based on PMU version 1 emulation by Avi Kivity.
[avi: adjust for cpuid.c]
[jan: fix anonymous field initialization for older gcc]
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Switch to using memdup_user when possible. This makes code more
smaller and compact, and prevents errors.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Switch to kmemdup() in two places to shorten the code and avoid possible bugs.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
percpu_xxx funcs are duplicated with this_cpu_xxx funcs, so replace them
for further code clean up.
And in preempt safe scenario, __this_cpu_xxx funcs has a bit better
performance since __this_cpu_xxx has no redundant preempt_disable()
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Move the mmu code in kvm_arch_vcpu_init() to kvm_mmu_create()
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
KVM_EXIT_HYPERCALL is not used anymore, so remove the code
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce id_to_memslot to get memslot by slot id
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce update_memslots to update slot which will be update to
kvm->memslots
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently, write protecting a slot needs to walk all the shadow pages
and checks ones which have a pte mapping a page in it.
The walk is overly heavy when dirty pages in that slot are not so many
and checking the shadow pages would result in unwanted cache pollution.
To mitigate this problem, we use rmap_write_protect() and check only
the sptes which can be reached from gfns marked in the dirty bitmap
when the number of dirty pages are less than that of shadow pages.
This criterion is reasonable in its meaning and worked well in our test:
write protection became some times faster than before when the ratio of
dirty pages are low and was not worse even when the ratio was near the
criterion.
Note that the locking for this write protection becomes fine grained.
The reason why this is safe is descripted in the comments.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Needed for the next patch which uses this number to decide how to write
protect a slot.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
The host side pv mmu support has been marked for feature removal in
January 2011. It's not in use, is slower than shadow or hardware
assisted paging, and a maintenance burden. It's November 2011, time to
remove it.
Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Fast prefetch spte for the unsync shadow page on invlpg path
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Remove the same code between emulator_pio_in_emulated and
emulator_pio_out_emulated
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If the emulation is caused by #PF and it is non-page_table writing instruction,
it means the VM-EXIT is caused by shadow page protected, we can zap the shadow
page and retry this instruction directly
The idea is from Avi
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a new vcpu->requests bit, KVM_REQ_IMMEDIATE_EXIT.
This bit requests that when next entering the guest, we should run it only
for as little as possible, and exit again.
We use this new option in nested VMX: When L1 launches L2, but L0 wishes L1
to continue running so it can inject an event to it, we unfortunately cannot
just pretend to have run L2 for a little while - We must really launch L2,
otherwise certain one-off vmcs12 parameters (namely, L1 injection into L2)
will be lost. So the existing code runs L2 in this case.
But L2 could potentially run for a long time until it exits, and the
injection into L1 will be delayed. The new KVM_REQ_IMMEDIATE_EXIT allows us
to request that L2 will be entered, as necessary, but will exit as soon as
possible after entry.
Our implementation of this request uses smp_send_reschedule() to send a
self-IPI, with interrupts disabled. The interrupts remain disabled until the
guest is entered, and then, after the entry is complete (often including
processing an injection and jumping to the relevant handler), the physical
interrupt is noticed and causes an exit.
On recent Intel processors, we could have achieved the same goal by using
MTF instead of a self-IPI. Another technique worth considering in the future
is to use VM_EXIT_ACK_INTR_ON_EXIT and a highest-priority vector IPI - to
slightly improve performance by avoiding the useless interrupt handler
which ends up being called when smp_send_reschedule() is used.
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Unlike all of the other cpuid bits, the TSC deadline timer bit is set
unconditionally, regardless of what userspace wants.
This is broken in several ways:
- if userspace doesn't use KVM_CREATE_IRQCHIP, and doesn't emulate the TSC
deadline timer feature, a guest that uses the feature will break
- live migration to older host kernels that don't support the TSC deadline
timer will cause the feature to be pulled from under the guest's feet;
breaking it
- guests that are broken wrt the feature will fail.
Fix by not enabling the feature automatically; instead report it to userspace.
Because the feature depends on KVM_CREATE_IRQCHIP, which we cannot guarantee
will be called, we expose it via a KVM_CAP_TSC_DEADLINE_TIMER and not
KVM_GET_SUPPORTED_CPUID.
Fixes the Illumos guest kernel, which uses the TSC deadline timer feature.
[avi: add the KVM_CAP + documentation]
Reported-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (33 commits)
iommu/core: Remove global iommu_ops and register_iommu
iommu/msm: Use bus_set_iommu instead of register_iommu
iommu/omap: Use bus_set_iommu instead of register_iommu
iommu/vt-d: Use bus_set_iommu instead of register_iommu
iommu/amd: Use bus_set_iommu instead of register_iommu
iommu/core: Use bus->iommu_ops in the iommu-api
iommu/core: Convert iommu_found to iommu_present
iommu/core: Add bus_type parameter to iommu_domain_alloc
Driver core: Add iommu_ops to bus_type
iommu/core: Define iommu_ops and register_iommu only with CONFIG_IOMMU_API
iommu/amd: Fix wrong shift direction
iommu/omap: always provide iommu debug code
iommu/core: let drivers know if an iommu fault handler isn't installed
iommu/core: export iommu_set_fault_handler()
iommu/omap: Fix build error with !IOMMU_SUPPORT
iommu/omap: Migrate to the generic fault report mechanism
iommu/core: Add fault reporting mechanism
iommu/core: Use PAGE_SIZE instead of hard-coded value
iommu/core: use the existing IS_ALIGNED macro
iommu/msm: ->unmap() should return order of unmapped page
...
Fixup trivial conflicts in drivers/iommu/Makefile: "move omap iommu to
dedicated iommu folder" vs "Rename the DMAR and INTR_REMAP config
options" just happened to touch lines next to each other.
With per-bus iommu_ops the iommu_found function needs to
work on a bus_type too. This patch adds a bus_type parameter
to that function and converts all call-places.
The function is also renamed to iommu_present because the
function now checks if an iommu is present for a given bus
and does not check for a global iommu anymore.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
If simultaneous NMIs happen, we're supposed to queue the second
and next (collapsing them), but currently we sometimes collapse
the second into the first.
Fix by using a counter for pending NMIs instead of a bool; since
the counter limit depends on whether the processor is currently
in an NMI handler, which can only be checked in vcpu context
(via the NMI mask), we add a new KVM_REQ_NMI to request recalculation
of the counter.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM assumed in several places that reading the TSC MSR returns the value for
L1. This is incorrect, because when L2 is running, the correct TSC read exit
emulation is to return L2's value.
We therefore add a new x86_ops function, read_l1_tsc, to use in places that
specifically need to read the L1 TSC, NOT the TSC of the current level of
guest.
Note that one change, of one line in kvm_arch_vcpu_load, is made redundant
by a different patch sent by Zachary Amsden (and not yet applied):
kvm_arch_vcpu_load() should not read the guest TSC, and if it didn't, of
course we didn't have to change the call of kvm_get_msr() to read_l1_tsc().
[avi: moved callback to kvm_x86_ops tsc block]
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Acked-by: Zachary Amsdem <zamsden@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Windows Server 2008 SP2 checked build with smp > 1 BSOD's during
boot due to lack of microcode update:
*** Assertion failed: The system BIOS on this machine does not properly
support the processor. The system BIOS did not load any microcode update.
A BIOS containing the latest microcode update is needed for system reliability.
(CurrentUpdateRevision != 0)
*** Source File: d:\longhorn\base\hals\update\intelupd\update.c, line 440
Report a non-zero microcode update signature to make it happy.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Return EMULATION_OK/FAILED consistently. Also treat instruction fetch
errors, not restricted to X86EMUL_UNHANDLEABLE, as EMULATION_FAILED;
although this cannot happen in practice, the current logic will continue
the emulation even if the decoder fails to fetch the instruction.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently the method of dealing with an IO operation on a bus (PIO/MMIO)
is to call the read or write callback for each device registered
on the bus until we find a device which handles it.
Since the number of devices on a bus can be significant due to ioeventfds
and coalesced MMIO zones, this leads to a lot of overhead on each IO
operation.
Instead of registering devices, we now register ranges which points to
a device. Lookup is done using an efficient bsearch instead of a linear
search.
Performance test was conducted by comparing exit count per second with
200 ioeventfds created on one byte and the guest is trying to access a
different byte continuously (triggering usermode exits).
Before the patch the guest has achieved 259k exits per second, after the
patch the guest does 274k exits per second.
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Commit 0945d4b228 tried to fix the get_msr path for the
HV_X64_MSR_APIC_ASSIST_PAGE msr, but was poorly tested. We should be
returning 0 if the read succeeded, and passing the value back to the
caller via the pdata out argument, not returning the value directly.
Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
"get" support for the HV_X64_MSR_APIC_ASSIST_PAGE msr was missing, even
though it is explicitly enumerated as something the vmm should save in
msrs_to_save and reported to userland via the KVM_GET_MSR_INDEX_LIST
ioctl.
Add "get" support for HV_X64_MSR_APIC_ASSIST_PAGE. We simply return the
guest visible value of this register, which seems to be correct as a set
on the register is validated for us already.
Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The patch raises the hard limit of VCPU count to 254.
This will allow developers to easily work on scalability
and will allow users to test high VCPU setups easily without
patching the kernel.
To prevent possible issues with current setups, KVM_CAP_NR_VCPUS
now returns the recommended VCPU limit (which is still 64) - this
should be a safe value for everybody, while a new KVM_CAP_MAX_VCPUS
returns the hard limit which is now 254.
Cc: Avi Kivity <avi@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Suggested-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Using the read/write operation to remove the same code
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The operations of read emulation and write emulation are very similar, so we
can abstract the operation of them, in larter patch, it is used to cleanup the
same code
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If the range spans a page boundary, the mmio access can be broke, fix it as
write emulation.
And we already get the guest physical address, so use it to read guest data
directly to avoid walking guest page table again
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The idea is from Avi:
| We could cache the result of a miss in an spte by using a reserved bit, and
| checking the page fault error code (or seeing if we get an ept violation or
| ept misconfiguration), so if we get repeated mmio on a page, we don't need to
| search the slot list/tree.
| (https://lkml.org/lkml/2011/2/22/221)
When the page fault is caused by mmio, we cache the info in the shadow page
table, and also set the reserved bits in the shadow page table, so if the mmio
is caused again, we can quickly identify it and emulate it directly
Searching mmio gfn in memslots is heavy since we need to walk all memeslots, it
can be reduced by this feature, and also avoid walking guest page table for
soft mmu.
[jan: fix operator precedence issue]
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The idea is from Avi:
| Maybe it's time to kill off bypass_guest_pf=1. It's not as effective as
| it used to be, since unsync pages always use shadow_trap_nonpresent_pte,
| and since we convert between the two nonpresent_ptes during sync and unsync.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If the page fault is caused by mmio, we can cache the mmio info, later, we do
not need to walk guest page table and quickly know it is a mmio fault while we
emulate the mmio instruction
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce vcpu_mmio_gva_to_gpa to translate the gva to gpa, we can use it
to cleanup the code between read emulation and write emulation
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
To implement steal time, we need the hypervisor to pass the guest
information about how much time was spent running other processes
outside the VM, while the vcpu had meaningful work to do - halt
time does not count.
This information is acquired through the run_delay field of
delayacct/schedstats infrastructure, that counts time spent in a
runqueue but not running.
Steal time is a per-cpu information, so the traditional MSR-based
infrastructure is used. A new msr, KVM_MSR_STEAL_TIME, holds the
memory area address containing information about steal time
This patch contains the hypervisor part of the steal time infrasructure,
and can be backported independently of the guest portion.
[avi, yongjie: export delayacct_on, to avoid build failures in some configs]
Signed-off-by: Glauber Costa <glommer@redhat.com>
Tested-by: Eric B Munson <emunson@mgebm.net>
CC: Rik van Riel <riel@redhat.com>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Yongjie Ren <yongjie.ren@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch exposes ERMS feature to KVM guests.
The REP MOVSB/STOSB instruction can enhance fast strings attempts to
move as much of the data with larger size load/stores as possible.
Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch exposes DRNG feature to KVM guests.
The RDRAND instruction can provide software with sequences of
random numbers generated from white noise.
Signed-off-by: Yang, Wei <wei.y.yang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
commit 123108f1c1aafd51d6a5c79cc04d7999dd88a930 tried to fix KVMs
XSAVE valid feature scanning, but it was wrong. It was not considering
the sparse nature of this bitfield, instead reading values from
uninitialized members of the entries array.
This patch now separates subleaf indicies from KVM's array indicies
and fills the entry before querying it's value.
This fixes AVX support in KVM guests.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This saves a lot of pointless casts x86_emulate_ctxt and decode_cache.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The name eip conflicts with a field of the same name in x86_emulate_ctxt,
which we plan to fold decode_cache into.
The name _eip is unfortunate, but what's really needed is a refactoring
here, not a better name.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We should use the local variables ctxt and c when the emulate_ctxt and
decode appears many times. At least, we need to be consistent about
how we use these in a function.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch includes a utility function for decoding pointer operands of VMX
instructions issued by L1 (a guest hypervisor)
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch allows the guest to enable the VMXE bit in CR4, which is a
prerequisite to running VMXON.
Whether to allow setting the VMXE bit now depends on the architecture (svm
or vmx), so its checking has moved to kvm_x86_ops->set_cr4(). This function
now returns an int: If kvm_x86_ops->set_cr4() returns 1, __kvm_set_cr4()
will also return 1, and this will cause kvm_set_cr4() will throw a #GP.
Turning on the VMXE bit is allowed only when the nested VMX feature is
enabled, and turning it off is forbidden after a vmxon.
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
During tracing the emulator, we noticed that init_emulate_ctxt()
sometimes took a bit longer time than we expected.
This patch is for mitigating the problem by some degree.
By looking into the function, we soon notice that it clears the whole
decode_cache whose size is about 2.5K bytes now. Furthermore, most of
the bytes are taken for the two read_cache arrays, which are used only
by a few instructions.
Considering the fact that we are not assuming the cache arrays have
been cleared when we store actual data, we do not need to clear the
arrays: 2K bytes elimination. In addition, we can avoid clearing the
fetch_cache and regs arrays.
This patch changes the initialization not to clear the arrays.
On our 64-bit host, init_emulate_ctxt() becomes 0.3 to 0.5us faster with
this patch applied.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Use a local pointer to the emulate_ctxt for simplicity. Then, arrange
the hard-to-read mode selection lines neatly.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
So far kvm_arch_vcpu_setup is responsible for freeing the vcpu struct if
it fails. Move this confusing resonsibility back into the hands of
kvm_vm_ioctl_create_vcpu. Only kvm_arch_vcpu_setup of x86 is affected,
all other archs cannot fail.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of blacklisting known-unsupported cpuid leaves, whitelist known-
supported leaves. This is more conservative and prevents us from reporting
features we don't support. Also whitelist a few more leaves while at it.
Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Simply use __copy_to_user/__clear_user to write guest page since we have
already verified the user address when the memslot is set
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Dereference it in the actual users.
This not only cleans up the emulator but also makes it easy to convert
the old emulation functions to the new em_xxx() form later.
Note: Remove some inline keywords to let the compiler decide inlining.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Instead of separate accessors for the segment selector and cached descriptor,
use one accessor for both. This simplifies the code somewhat.
Signed-off-by: Avi Kivity <avi@redhat.com>
The CPUIDs for Centaur are added, and then the features of
PadLock hardware engine on VIA CPU, such as "ace", "ace_en"
and so on, can be passed into the kvm guest.
Signed-off-by: Brilly Wu <brillywu@viatech.com.cn>
Signed-off-by: Kary Jin <karyjin@viatech.com.cn>
Signed-off-by: Avi Kivity <avi@redhat.com>
mmio_index should be taken into account when copying data from
userspace.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Avoid using ctxt->vcpu; we can do everything with ->get_cr() and ->set_cr().
A side effect is that we no longer activate the fpu on emulated CLTS; but that
should be very rare.
Signed-off-by: Avi Kivity <avi@redhat.com>
Making the emulator caller agnostic.
[Takuya Yoshikawa: fix typo leading to LDT failures]
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
The last_guest_tsc is used in vcpu_load to adjust the
tsc_offset since tsc-scaling is merged. So the
last_guest_tsc needs to be updated in vcpu_put instead of
the the last_host_tsc. This is fixed with this patch.
Reported-by: Jan Kiszka <jan.kiszka@web.de>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When doing a soft int, we need to bump eip before pushing it to
the stack. Otherwise we'll do the int a second time.
[apw@canonical.com: merged eip update as per Jan's recommendation.]
Signed-off-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently we sync registers back and forth before/after exiting
to userspace for IO, but during IO device model shouldn't need to
read/write the registers, so we can as well skip those sync points. The
only exaception is broken vmware backdor interface. The new code sync
registers content during IO only if registers are read from/written to
by userspace in the middle of the IO operation and this almost never
happens in practise.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch implements two new vm-ioctls to get and set the
virtual_tsc_khz if the machine supports tsc-scaling. Setting
the tsc-frequency is only possible before userspace creates
any vcpu.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
With TSC scaling in SVM the tsc-offset needs to be
calculated differently. This patch propagates this
calculation into the architecture specific modules so that
this complexity can be handled there.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The calculation of the tsc_delta value to ensure a
forward-going tsc for the guest is a function of the
host-tsc. This works as long as the guests tsc_khz is equal
to the hosts tsc_khz. With tsc-scaling hardware support this
is not longer true and the tsc_delta needs to be calculated
using guest_tsc values.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch changes the kvm_guest_time_update function to use
TSC frequency the guest actually has for updating its clock.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds all necessary intercept checks for
instructions that access the crX registers.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a callback into kvm_x86_ops so that svm and
vmx code can do intercept checks on emulated instructions.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch prevents the changed CPU state to be written back
when the emulator detected that the instruction was
intercepted by the guest.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When running in guest mode, certain instructions can be intercepted by
hardware. This also holds for nested guests running on emulated
virtualization hardware, in particular instructions emulated by kvm
itself.
This patch adds a framework for intercepting instructions. If an
instruction is marked for interception, and if we're running in guest
mode, a callback is called to check whether an intercept is needed or
not. The callback is called at three points in time: immediately after
beginning execution, after checking privilge exceptions, and after
checking memory exception. This suits the different interception points
defined for different instructions and for the various virtualization
instruction sets.
In addition, a new X86EMUL_INTERCEPT is defined, which any callback or
memory access may define, allowing the more complicated intercepts to be
implemented in existing callbacks.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Since sse instructions can issue 16-byte mmios, we need to support them. We
can't increase the kvm_run mmio buffer size to 16 bytes without breaking
compatibility, so instead we break the large mmios into two smaller 8-byte
ones. Since the bus is 64-bit we aren't breaking any atomicity guarantees.
Signed-off-by: Avi Kivity <avi@redhat.com>
As Avi recently mentioned, the new standard mechanism for exposing features
is KVM_GET_SUPPORTED_CPUID, not spamming CAPs. For some reason async pf
missed that.
So expose async_pf here.
Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Gleb Natapov <gleb@redhat.com>
CC: Avi Kivity <avi@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Some rflags bits are owned by the host, not guest, so we need to use
kvm_get_rflags() to strip those bits away or kvm_set_rflags() to add them
back.
Signed-off-by: Avi Kivity <avi@redhat.com>
If KVM cannot find an exact match for a requested CPUID leaf, the
code will try to find the closest match instead of simply confessing
it's failure.
The implementation was meant to satisfy the CPUID specification, but
did not properly check for extended and standard leaves and also
didn't account for the index subleaf.
Beside that this rule only applies to CPUID intercepts, which is not
the only user of the kvm_find_cpuid_entry() function.
So fix this algorithm and call it from kvm_emulate_cpuid().
This fixes a crash of newer Linux kernels as KVM guests on
AMD Bulldozer CPUs, where bogus values were returned in response to
a CPUID intercept.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When KVM scans the 0xD CPUID leaf for propagating the XSAVE save area
leaves, it assumes that the leaves are contigious and stops at the
first zero one. On AMD hardware there is a gap, though, as LWP uses
leaf 62 to announce it's state save area.
So lets iterate through all 64 possible leaves and simply skip zero
ones to also cover later features.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Flush TLB if PGD entry is changed in i386 PAE mode
x86, dumpstack: Correct stack dump info when frame pointer is available
x86: Clean up csum-copy_64.S a bit
x86: Fix common misspellings
x86: Fix misspelling and align params
x86: Use PentiumPro-optimized partial_csum() on VIA C7
They were generated by 'codespell' and then manually reviewed.
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: trivial@kernel.org
LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
commit 387b9f97750444728962b236987fbe8ee8cc4f8c moved kvm_request_guest_time_update(vcpu),
breaking 32bit SMP guests using kvm-clock. Fix this by moving (new) clock update function
to proper place.
Signed-off-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Current implementation truncates upper 32bit of TR base address during IO
permission bitmap check. The patch fixes this.
Reported-and-tested-by: Francis Moreau <francis.moro@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
kvm_mmu_calculate_mmu_pages need to walk all memslots and it's protected by
kvm->slots_lock, so move it out of mmu spinlock
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
use EFER_SCE, EFER_LME and EFER_LMA instead of magic numbers.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The hash array of async gfns may still contain some left gfns after
kvm_clear_async_pf_completion_queue() called, need to clear them.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
isr_ack logic was added by e48258009d to avoid unnecessary IPIs. Back
then it made sense, but now the code checks that vcpu is ready to accept
interrupt before sending IPI, so this logic is no longer needed. The
patch removes it.
Fixes a regression with Debian/Hurd.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reported-and-tested-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The interrupt injection logic looks something like
if an nmi is pending, and nmi injection allowed
inject nmi
if an nmi is pending
request exit on nmi window
the problem is that "nmi is pending" can be set asynchronously by
the PIT; if it happens to fire between the two if statements, we
will request an nmi window even though nmi injection is allowed. On
SVM, this has disasterous results, since it causes eflags.TF to be
set in random guest code.
The fix is simple; make nmi_pending synchronous using the standard
vcpu->requests mechanism; this ensures the code above is completely
synchronous wrt nmi_pending.
Signed-off-by: Avi Kivity <avi@redhat.com>
Use the new support in the emulator, and drop the ad-hoc code in x86.c.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
x86_decode_insn() doesn't return X86EMUL_* values, so the check
for X86EMUL_PROPOGATE_FAULT will always fail. There is a proper
check later on, so there is no need for a replacement for this
code.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When a vcpu is reset, kvmclock page keeps being written to this days.
This is wrong and inconsistent: a cpu reset should take it to its
initial state.
Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
A correction to Intel cpu model CPUID data (patch queued)
caused winxp to BSOD when booted with a Penryn model.
This was traced to the CPUID "model" field correction from
6 -> 23 (as is proper for a Penryn class of cpu). Only in
this case does the problem surface.
The cause for this failure is winxp accessing the BBL_CR_CTL3
MSR which is unsupported by current kvm, appears to be a
legacy MSR not fully characterized yet existing in current
silicon, and is apparently carried forward in MSR space to
accommodate vintage code as here. It is not yet conclusive
whether this MSR implements any of its legacy functionality
or is just an ornamental dud for compatibility. While I
found no silicon version specific documentation link to
this MSR, a general description exists in Intel's developer's
reference which agrees with the functional behavior of
other bootloader/kernel code I've examined accessing
BBL_CR_CTL3. Regrettably winxp appears to be setting bit #19
called out as "reserved" in the above document.
So to minimally accommodate this MSR, kvm msr get will provide
the equivalent mock data and kvm msr write will simply toss the
guest passed data without interpretation. While this treatment
of BBL_CR_CTL3 addresses the immediate problem, the approach may
be modified pending clarification from Intel.
Signed-off-by: john cooper <john.cooper@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently we keep track of only two states: guest mode and host
mode. This patch adds an "exiting guest mode" state that tells
us that an IPI will happen soon, so unless we need to wait for the
IPI, we can avoid it completely.
Also
1: No need atomically to read/write ->mode in vcpu's thread
2: reorganize struct kvm_vcpu to make ->mode and ->requests
in the same cache line explicitly
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This case is a pure user space error we do not need to record. Moreover,
it can be misused to flood the kernel log. Remove it.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* 'kvm-updates/2.6.38' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (142 commits)
KVM: Initialize fpu state in preemptible context
KVM: VMX: when entering real mode align segment base to 16 bytes
KVM: MMU: handle 'map_writable' in set_spte() function
KVM: MMU: audit: allow audit more guests at the same time
KVM: Fetch guest cr3 from hardware on demand
KVM: Replace reads of vcpu->arch.cr3 by an accessor
KVM: MMU: only write protect mappings at pagetable level
KVM: VMX: Correct asm constraint in vmcs_load()/vmcs_clear()
KVM: MMU: Initialize base_role for tdp mmus
KVM: VMX: Optimize atomic EFER load
KVM: VMX: Add definitions for more vm entry/exit control bits
KVM: SVM: copy instruction bytes from VMCB
KVM: SVM: implement enhanced INVLPG intercept
KVM: SVM: enhance mov DR intercept handler
KVM: SVM: enhance MOV CR intercept handler
KVM: SVM: add new SVM feature bit names
KVM: cleanup emulate_instruction
KVM: move complete_insn_gp() into x86.c
KVM: x86: fix CR8 handling
KVM guest: Fix kvm clock initialization when it's configured out
...
init_fpu() (which is indirectly called by the fpu switching code) assumes
it is in process context. Rather than makeing init_fpu() use an atomic
allocation, which can cause a task to be killed, make sure the fpu is
already initialized when we enter the run loop.
KVM-Stable-Tag.
Reported-and-tested-by: Kirill A. Shutemov <kas@openvz.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of syncing the guest cr3 every exit, which is expensince on vmx
with ept enabled, sync it only on demand.
[sheng: fix incorrect cr3 seen by Windows XP]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
In case of a nested page fault or an intercepted #PF newer SVM
implementations provide a copy of the faulting instruction bytes
in the VMCB.
Use these bytes to feed the instruction emulator and avoid the costly
guest instruction fetch in this case.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
emulate_instruction had many callers, but only one used all
parameters. One parameter was unused, another one is now
hidden by a wrapper function (required for a future addition
anyway), so most callers use now a shorter parameter list.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
move the complete_insn_gp() helper function out of the VMX part
into the generic x86 part to make it usable by SVM.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The handling of CR8 writes in KVM is currently somewhat cumbersome.
This patch makes it look like the other CR register handlers
and fixes a possible issue in VMX, where the RIP would be incremented
despite an injected #GP.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
In KVM_CREATE_IRQCHIP, kvm_io_bus_unregister_dev() is called without taking
slots_lock in the error handling path.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Retry #PF for softmmu only when the current vcpu has the same cr3 as the time
when #PF occurs
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch prevents that emulation failures which result
from emulating an instruction for an L2-Guest results in
being reported to userspace.
Without this patch a malicious L2-Guest would be able to
kill the L1 by triggering a race-condition between an vmexit
and the instruction emulator.
With this patch the L2 will most likely only kill itself in
this situation.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently page fault cr2 and nesting infomation are carried outside
the fault data structure. Instead they are placed in the vcpu struct,
which results in confusion as global variables are manipulated instead
of passing parameters.
Fix this issue by adding address and nested fields to struct x86_exception,
so this struct can carry all information associated with a fault.
Signed-off-by: Avi Kivity <avi@redhat.com>
Tested-by: Joerg Roedel <joerg.roedel@amd.com>
Tested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Introduce a structure that can contain an exception to be passed back
to main kvm code.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This allows Linux to mask cpuid bits if, for example, nx is enabled on only
some cpus.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If apf is generated in L2 guest and is completed in L1 guest, it will
prefault this apf in L1 guest's mmu context.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If CR0.PG is changed, the page fault cann't be avoid when the prefault address
is accessed later
And it also fix a bug: it can retry a page enabled #PF in page disabled context
if mmu is shadow page
This idear is from Gleb Natapov
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
IA64 support forces us to abstract the allocation of the kvm structure.
But instead of mixing this up with arch-specific initialization and
doing the same on destruction, split both steps. This allows to move
generic destruction calls into generic code.
It also fixes error clean-up on failures of kvm_create_vm for IA64.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
In current code, it checks async pf completion out of the wait context,
like this:
if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
!vcpu->arch.apf.halted)
r = vcpu_enter_guest(vcpu);
else {
......
kvm_vcpu_block(vcpu)
^- waiting until 'async_pf.done' is not empty
}
kvm_check_async_pf_completion(vcpu)
^- delete list from async_pf.done
So, if we check aysnc pf completion first, it can be blocked at
kvm_vcpu_block
Fixed by mark the vcpu is unhalted in kvm_check_async_pf_completion()
path
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Micro optimization to avoid calling wbinvd twice on the CPU that has to
emulate it. As we might be preempted between smp_call_function_many and
the local wbinvd, the cache might be filled again so that real work
could be done uselessly.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently x86's kvm_vm_ioctl_get_dirty_log() needs to allocate a bitmap by
vmalloc() which will be used in the next logging and this has been causing
bad effect to VGA and live-migration: vmalloc() consumes extra systime,
triggers tlb flush, etc.
This patch resolves this issue by pre-allocating one more bitmap and switching
between two bitmaps during dirty logging.
Performance improvement:
I measured performance for the case of VGA update by trace-cmd.
The result was 1.5 times faster than the original one.
In the case of live migration, the improvement ratio depends on the workload
and the guest memory size. In general, the larger the memory size is the more
benefits we get.
Note:
This does not change other architectures's logic but the allocation size
becomes twice. This will increase the actual memory consumption only when
the new size changes the number of pages allocated by vmalloc().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If guest indicates that it can handle async pf in kernel mode too send
it, but only if interrupts are enabled.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If guest can detect that it runs in non-preemptable context it can
handle async PFs at any time, so let host know that it can send async
PF even if guest cpu is not in userspace.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Send async page fault to a PV guest if it accesses swapped out memory.
Guest will choose another task to run upon receiving the fault.
Allow async page fault injection only when guest is in user mode since
otherwise guest may be in non-sleepable context and will not be able
to reschedule.
Vcpu will be halted if guest will fault on the same page again or if
vcpu executes kernel code.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Keep track of memslots changes by keeping generation number in memslots
structure. Provide kvm_write_guest_cached() function that skips
gfn_to_hva() translation if memslots was not changed since previous
invocation.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page. Do it only when tdp is enabled for now. Shadow paging case is
more complicated. CR[034] and EFER registers should be switched before
doing mapping and then switched back.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If a guest accesses swapped out memory do not swap it in from vcpu thread
context. Schedule work to do swapping and put vcpu into halted state
instead.
Interrupts will still be delivered to the guest and if interrupt will
cause reschedule guest will continue to run another task.
[avi: remove call to get_user_pages_noio(), nacked by Linus; this
makes everything synchrnous again]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
gameport: use this_cpu_read instead of lookup
x86: udelay: Use this_cpu_read to avoid address calculation
x86: Use this_cpu_inc_return for nmi counter
x86: Replace uses of current_cpu_data with this_cpu ops
x86: Use this_cpu_ops to optimize code
vmstat: User per cpu atomics to avoid interrupt disable / enable
irq_work: Use per cpu atomics instead of regular atomics
cpuops: Use cmpxchg for xchg to avoid lock semantics
x86: this_cpu_cmpxchg and this_cpu_xchg operations
percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
percpu,x86: relocate this_cpu_add_return() and friends
connector: Use this_cpu operations
xen: Use this_cpu_inc_return
taskstats: Use this_cpu_ops
random: Use this_cpu_inc_return
fs: Use this_cpu_inc_return in buffer.c
highmem: Use this_cpu_xx_return() operations
vmstat: Use this_cpu_inc_return for vm statistics
x86: Support for this_cpu_add, sub, dec, inc_return
percpu: Generic support for this_cpu_add, sub, dec, inc_return
...
Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.
The only bit of EFER that affects the mmu is NX, and this is already
accounted for (LME only takes effect when changing cr0).
Based on a patch by Hillf Danton.
Signed-off-by: Avi Kivity <avi@redhat.com>
Go through x86 code and replace __get_cpu_var and get_cpu_var
instances that refer to a scalar and are not used for address
determinations.
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
To support xsave properly for the guest the SVM module need
software support for it. As long as this is not present do
not report the xsave as supported feature in cpuid.
As a side-effect this patch moves the bit() helper function
into the x86.h file so that it can be used in svm.c too.
KVM-Stable-Tag.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
CPUID's OSXSAVE is a mirror of CR4.OSXSAVE bit. We need to update the CPUID
after migration.
KVM-Stable-Tag.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
smp_call_function_many is specified to be called only with preemption
disabled. Fulfill this requirement.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Structures kvm_vcpu_events, kvm_debugregs, kvm_pit_state2 and
kvm_clock_data are copied to userland with some padding and reserved
fields unitialized. It leads to leaking of contents of kernel stack
memory. We have to initialize them to zero.
In patch v1 Jan Kiszka suggested to fill reserved fields with zeros
instead of memset'ting the whole struct. It makes sense as these
fields are explicitly marked as padding. No more fields need zeroing.
KVM-Stable-Tag.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
I have observed the following bug trigger:
1. userspace calls GET_DIRTY_LOG
2. kvm_mmu_slot_remove_write_access is called and makes a page ro
3. page fault happens and makes the page writeable
fault is logged in the bitmap appropriately
4. kvm_vm_ioctl_get_dirty_log swaps slot pointers
a lot of time passes
5. guest writes into the page
6. userspace calls GET_DIRTY_LOG
At point (5), bitmap is clean and page is writeable,
thus, guest modification of memory is not logged
and GET_DIRTY_LOG returns an empty bitmap.
The rule is that all pages are either dirty in the current bitmap,
or write-protected, which is violated here.
It seems that just moving kvm_mmu_slot_remove_write_access down
to after the slot pointer swap should fix this bug.
KVM-Stable-Tag.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (321 commits)
KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages
KVM: Fix signature of kvm_iommu_map_pages stub
KVM: MCE: Send SRAR SIGBUS directly
KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
KVM: fix typo in copyright notice
KVM: Disable interrupts around get_kernel_ns()
KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address
KVM: MMU: move access code parsing to FNAME(walk_addr) function
KVM: MMU: audit: check whether have unsync sps after root sync
KVM: MMU: audit: introduce audit_printk to cleanup audit code
KVM: MMU: audit: unregister audit tracepoints before module unloaded
KVM: MMU: audit: fix vcpu's spte walking
KVM: MMU: set access bit for direct mapping
KVM: MMU: cleanup for error mask set while walk guest page table
KVM: MMU: update 'root_hpa' out of loop in PAE shadow path
KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()
KVM: x86: Fix constant type in kvm_get_time_scale
KVM: VMX: Add AX to list of registers clobbered by guest switch
KVM guest: Move a printk that's using the clock before it's ready
KVM: x86: TSC catchup mode
...
Now we have MCG_SER_P (and corresponding SRAO/SRAR MCE) support in
kernel and QEMU-KVM, the MCG_SER_P should be added into
KVM_MCE_CAP_SUPPORTED to make all these code really works.
Reported-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
get_kernel_ns() wants preemption disabled. It doesn't make a lot of sense
during the get/set ioctls (no way to make them non-racy) but the callee wants
it.
Signed-off-by: Avi Kivity <avi@redhat.com>
Older gcc versions complain about the improper type (for x86-32), 4.5
seems to fix this silently. However, we should better use the right type
initially.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Negate the effects of AN TYM spell while kvm thread is preempted by tracking
conversion factor to the highest TSC rate and catching the TSC up when it has
fallen behind the kernel view of time. Note that once triggered, we don't
turn off catchup mode.
A slightly more clever version of this is possible, which only does catchup
when TSC rate drops, and which specifically targets only CPUs with broken
TSC, but since these all are considered unstable_tsc(), this patch covers
all necessary cases.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This just changes some names to better reflect the usage they
will be given. Separated out to keep confusion to a minimum.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The math in kvm_get_time_scale relies on the fact that
NSEC_PER_SEC < 2^32. To use the same function to compute
arbitrary time scales, we must extend the first reduction
step to shrink the base rate to a 32-bit value, and
possibly reduce the scaled rate into a 32-bit as well.
Note we must take care to avoid an arithmetic overflow
when scaling up the tps32 value (this could not happen
with the fixed scaled value of NSEC_PER_SEC, but can
happen with scaled rates above 2^31.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This adds a wrapper function kvm_inject_realmode_interrupt() around the
emulator function emulate_int_real() to allow real mode interrupt injection.
[avi: initialize operand and address sizes before emulating interrupts]
[avi: initialize rip for real mode interrupt injection]
[avi: clear interrupt pending flag after emulating interrupt injection]
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The PIC code used to be called from preempt_disable() context, which
wasn't very good for PREEMPT_RT. That is no longer the case, so move
back from raw_spinlock_t to spinlock_t.
Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If preempted after kvmclock values are updated, but before hardware
virtualization is entered, the last tsc time as read by the guest is
never set. It underflows the next time kvmclock is updated if there
has not yet been a successful entry / exit into hardware virt.
Fix this by simply setting last_tsc to the newly read tsc value so
that any computed nsec advance of kvmclock is nulled.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch moves the detection whether a page-fault was
nested or not out of the error code and moves it into a
separate variable in the fault struct.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Change the interrupt injection code to work from preemptible, interrupts
enabled context. This works by adding a ->cancel_injection() operation
that undoes an injection in case we were not able to actually enter the guest
(this condition could never happen with atomic injection).
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of blindly attempting to inject an event before each guest entry,
check for a possible event first in vcpu->requests. Sites that can trigger
event injection are modified to set KVM_REQ_EVENT:
- interrupt, nmi window opening
- ppr updates
- i8259 output changes
- local apic irr changes
- rflags updates
- gif flag set
- event set on exit
This improves non-injecting entry performance, and sets the stage for
non-atomic injection.
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch fixes a bug in KVM where it _always_ reports the
support of the SVM feature to userspace. But KVM only
supports SVM on AMD hardware and only when it is enabled in
the kernel module. This patch fixes the wrong reporting.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This function need to be able to load the pdptrs from any
mmu context currently in use. So change this function to
take an kvm_mmu parameter to fit these needs.
As a side effect this patch also moves the cached pdptrs
from vcpu_arch into the kvm_mmu struct.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
KVM currently ignores fetch faults in the instruction
emulator. With nested-npt we could have such faults. This
patch adds the code to handle these.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch implements logic to make sure that either a
page-fault/page-fault-vmexit or a nested-page-fault-vmexit
is propagated back to the guest.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces the init_kvm_nested_mmu() function
which is used to re-initialize the nested mmu when the l2
guest changes its paging mode.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces the kvm_read_guest_page_x86 function
which reads from the physical memory of the guest. If the
guest is running in guest-mode itself with nested paging
enabled it will read from the guest's guest physical memory
instead.
The patch also changes changes the code to use this function
where it is necessary.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds a function which can read from the guests
physical memory or from the guest's guest physical memory.
This will be used in the two-dimensional page table walker.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces the walk_mmu pointer which points to
the mmu-context currently used for gva_to_gpa translations.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces a mmu-callback to translate gpa
addresses in the walk_addr code. This is later used to
translate l2_gpa addresses into l1_gpa addresses.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch introduces a struct with two new fields in
vcpu_arch for x86:
* fault.address
* fault.error_code
This will be used to correctly propagate page faults back
into the guest when we could have either an ordinary page
fault or a nested page fault. In the case of a nested page
fault the fault-address is different from the original
address that should be walked. So we need to keep track
about the real fault-address.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Some operating systems store data about the host processor at the
time of installation, and when booted on a more uptodate cpu tries
to read MSR_EBC_FREQUENCY_ID. This has been found with XP.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
MSR_K7_CLK_CTL is a no longer documented MSR, which is only relevant
on said old AMD CPU models. This change returns the expected value,
which the Linux kernel is expecting to avoid writing back the MSR,
plus it ignores all writes to the MSR.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
x86_emulate_insn() will return 1 if instruction can be restarted
without re-entering a guest.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Kernel time, which advances in discrete steps may progress much slower
than TSC. As a result, when kvmclock is adjusted to a new base, the
apparent time to the guest, which runs at a much higher, nsec scaled
rate based on the current TSC, may have already been observed to have
a larger value (kernel_ns + scaled tsc) than the value to which we are
setting it (kernel_ns + 0).
We must instead compute the clock as potentially observed by the guest
for kernel_ns to make sure it does not go backwards.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If there are active VCPUs which are marked as belonging to
a particular hardware CPU, request a clock sync for them when
enabling hardware; the TSC could be desynchronized on a newly
arriving CPU, and we need to recompute guests system time
relative to boot after a suspend event.
This covers both cases.
Note that it is acceptable to take the spinlock, as either
no other tasks will be running and no locks held (BSP after
resume), or other tasks will be guaranteed to drop the lock
relatively quickly (AP on CPU_STARTING).
Noting we now get clock synchronization requests for VCPUs
which are starting up (or restarting), it is tempting to
attempt to remove the arch/x86/kvm/x86.c CPU hot-notifiers
at this time, however it is not correct to do so; they are
required for systems with non-constant TSC as the frequency
may not be known immediately after the processor has started
until the cpufreq driver has had a chance to run and query
the chipset.
Updated: implement better locking semantics for hardware_enable
Removed the hack of dropping and retaking the lock by adding the
semantic that we always hold kvm_lock when hardware_enable is
called. The one place that doesn't need to worry about it is
resume, as resuming a frozen CPU, the spinlock won't be taken.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Make the match of TSC find TSC writes that are close to each other
instead of perfectly identical; this allows the compensator to also
work in migration / suspend scenarios.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Add a helper function to compute the kernel time and convert nanoseconds
back to CPU specific cycles. Note that these must not be called in preemptible
context, as that would mean the kernel could enter software suspend state,
which would cause non-atomic operation.
Also, convert the KVM_SET_CLOCK / KVM_GET_CLOCK ioctls to use the kernel
time helper, these should be bootbased as well.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When CPUs with unstable TSCs enter deep C-state, TSC may stop
running. This causes us to require resynchronization. Since
we can't tell when this may potentially happen, we assume the
worst by forcing re-compensation for it at every point the VCPU
task is descheduled.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Move the TSC control logic from the vendor backends into x86.c
by adding adjust_tsc_offset to x86 ops. Now all TSC decisions
can be done in one place.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If creating an SMP guest with unstable host TSC, issue a warning
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This simplifies much of the init code; we can now simply always
call tsc_khz_changed, optionally passing it a new value, or letting
it figure out the existing value (while interrupts are disabled, and
thus, by inference from the rule, not raceful against CPU hotplug or
frequency updates, which will issue IPIs to the local CPU to perform
this very same task).
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Attempt to synchronize TSCs which are reset to the same value. In the
case of a reliable hardware TSC, we can just re-use the same offset, but
on non-reliable hardware, we can get closer by adjusting the offset to
match the elapsed time.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Also, ensure that the storing of the offset and the reading of the TSC
are never preempted by taking a spinlock. While the lock is overkill
now, it is useful later in this patch series.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This is used only by the VMX code, and is not done properly;
if the TSC is indeed backwards, it is out of sync, and will
need proper handling in the logic at each and every CPU change.
For now, drop this test during init as misguided.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
arch.n_alloc_mmu_pages is a poor choice of name. This value truly
means, "the number of pages which _may_ be allocated". But,
reading the name, "n_alloc_mmu_pages" implies "the number of allocated
mmu pages", which is dead wrong.
It's really the high watermark, so let's give it a name to match:
nr_max_mmu_pages. This change will make the next few patches
much more obvious and easy to read.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The code for initializing the emulation context is duplicated at two
locations (emulate_instruction() and kvm_task_switch()). Separate it
in a separate function and call it from there.
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The patch adds a new member get_idt() to x86_emulate_ops.
It also adds a function to get the idt in order to be used by the emulator.
This is needed for real mode interrupt injection and the emulation of int
instructions.
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
No need to update vcpu state since instruction is in the middle of the
emulation.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
It doesn't ever change, so we don't need to pass it around everywhere.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The AMD extensions to AVX (FMA4, XOP) work on the same YMM register set
as AVX, so they are safe for guests to use, as long as AVX itself
is allowed. Add F16C and AES on the way for the same reasons.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
LKML-Reference: <1283778860-26843-4-git-send-email-andre.przywara@amd.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The AMD SSE5 feature set as-it has been replaced by some extensions
to the AVX instruction set. Thus the bit formerly advertised as SSE5
is re-used for one of these extensions (XOP).
Although this changes the /proc/cpuinfo output, it is not user visible, as
there are no CPUs (yet) having this feature.
To avoid confusion this should be added to the stable series, too.
Cc: stable@kernel.org [.32.x .34.x, .35.x]
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
LKML-Reference: <1283778860-26843-2-git-send-email-andre.przywara@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: PIT: free irq source id in handling error path
KVM: destroy workqueue on kvm_create_pit() failures
KVM: fix poison overwritten caused by using wrong xstate size
fpu.state is allocated from task_xstate_cachep, the size of task_xstate_cachep
is xstate_size. xstate_size is set from cpuid instruction, which is often
smaller than sizeof(struct xsave_struct). kvm is using sizeof(struct xsave_struct)
to fill in/out fpu.state.xsave, as what we allocated for fpu.state is
xstate_size, kernel will write out of memory and caused poison/redzone/padding
overwritten warnings.
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Reviewed-by: Sheng Yang <sheng@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Sheng Yang <sheng@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If the destination is a memory operand and the memory cannot
map to a valid page, the xchg instruction emulation and locked
instruction will not work on io regions and stuck in endless
loop. We should emulate exchange as write to fix it.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
With tdp enabled we should get into emulator only when emulating io, so
reexecution will always bring us back into emulator.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Userspace needs to reset and save/restore these MSRs.
The MCE banks are not exposed since their number varies from vcpu to vcpu.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When shadow pages are in use sometimes KVM try to emulate an instruction
when it accesses a shadowed page. If emulation fails KVM un-shadows the
page and reenter guest to allow vcpu to execute the instruction. If page
is not in shadow page hash KVM assumes that this was attempt to do MMIO
and reports emulation failure to userspace since there is no way to fix
the situation. This logic has a race though. If two vcpus tries to write
to the same shadowed page simultaneously both will enter emulator, but
only one of them will find the page in shadow page hash since the one who
founds it also removes it from there, so another cpu will report failure
to userspace and will abort the guest.
Fix this by checking (in addition to checking shadowed page hash) that
page that caused the emulation belongs to valid memory slot. If it is
then reenter the guest to allow vcpu to reexecute the instruction.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly
WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or
CLFLUSH, we need to maintain data consistency either by:
1: flushing cache (wbinvd) when the guest is scheduled out if there is no
wbinvd exit, or
2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits.
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
No need to reload the mmu in between two different vcpu->requests checks.
kvm_mmu_reload() may trigger KVM_REQ_TRIPLE_FAULT, but that will be caught
during atomic guest entry later.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Enable Intel(R) Advanced Vector Extension(AVX) for guest.
The detection of AVX feature includes OSXSAVE bit testing. When OSXSAVE bit is
not set, even if AVX is supported, the AVX instruction would result in UD as
well. So we're safe to expose AVX bits to guest directly.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If a process with a memory slot is COWed, the page will change its address
(despite having an elevated reference count). This breaks internal memory
slots which have their physical addresses loaded into vmcs registers (see
the APIC access memory slot).
Signed-off-by: Avi Kivity <avi@redhat.com>
As advertised in feature-removal-schedule.txt. Equivalent support is provided
by overlapping memory regions.
Signed-off-by: Avi Kivity <avi@redhat.com>
Instead of three temporary variables and three free calls, have one temporary
variable (with four names) and one free call.
Signed-off-by: Avi Kivity <avi@redhat.com>
On Intel, we call skip_emulated_instruction() even if we injected a #GP,
resulting in the #GP pointing at the wrong address.
Fix by injecting the exception and skipping the instruction at the same place,
so we can do just one or the other.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
On Intel, we call skip_emulated_instruction() even if we injected a #GP,
resulting in the #GP pointing at the wrong address.
Fix by injecting the exception and skipping the instruction at the same place,
so we can do just one or the other.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
On Intel, we call skip_emulated_instruction() even if we injected a #GP,
resulting in the #GP pointing at the wrong address.
Fix by injecting the exception and skipping the instruction at the same place,
so we can do just one or the other.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch enable guest to use XSAVE/XRSTOR instructions.
We assume that host_xcr0 would use all possible bits that OS supported.
And we loaded xcr0 in the same way we handled fpu - do it as late as we can.
Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Should use linux/uaccess.h instead of asm/uaccess.h
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Memory allocation may fail. Propagate such errors.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
We can avoid unnecessary fpu load when userspace process
didn't use FPU frequently.
Derived from Avi's idea.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Now that all arch specific ioctls have centralized locking, it is easy to
move it to the central dispatcher.
Signed-off-by: Avi Kivity <avi@redhat.com>
All vcpu ioctls need to be locked, so instead of locking each one specifically
we lock at the generic dispatcher.
This patch only updates generic ioctls and leaves arch specific ioctls alone.
Signed-off-by: Avi Kivity <avi@redhat.com>
Only modifying some bits of CR0/CR4 needs paging mode switch.
Modify EFER.NXE bit would result in reserved bit updates.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
mmu.free() already set root_hpa to INVALID_PAGE, no need to do it again in the
destory_kvm_mmu().
kvm_x86_ops->set_cr4() and set_efer() already assign cr4/efer to
vcpu->arch.cr4/efer, no need to do it again later.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Do not kill VM when instruction emulation fails. Inject #UD and report
failure to userspace instead. Userspace may choose to reenter guest if
vcpu is in userspace (cpl == 3) in which case guest OS will kill
offending process and continue running.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM_REQ_KICK poisons vcpu->requests by having a bit set during normal
operation. This causes the fast path check for a clear vcpu->requests
to fail all the time, triggering tons of atomic operations.
Fix by replacing KVM_REQ_KICK with a vcpu->guest_mode atomic.
Signed-off-by: Avi Kivity <avi@redhat.com>
Return exception as a result of instruction emulation and handle
injection in KVM code.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Return new RIP as part of instruction emulation result instead of
updating KVM's RIP from x86 emulator code.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Return error to x86 emulator instead of injection exception behind its back.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
It is not called directly outside of the file it's defined in anymore.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently emulator returns -1 when emulation failed or IO is needed.
Caller tries to guess whether emulation failed by looking at other
variables. Make it easier for caller to recognise error condition by
always returning -1 in case of failure. For this new emulator
internal return value X86EMUL_IO_NEEDED is introduced. It is used to
distinguish between error condition (which returns X86EMUL_UNHANDLEABLE)
and condition that requires IO exit to userspace to continue emulation.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Fill in run->mmio details in (read|write)_emulated function just like
pio does. There is no point in filling only vcpu fields there just to
copy them into vcpu->run a little bit later.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Make (get|set)_dr() callback return error if it fails instead of
injecting exception behind emulator's back.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Make set_cr() callback return error if it fails instead of injecting #GP
behind emulator's back.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
On VMX it is expensive to call get_cached_descriptor() just to get segment
base since multiple vmcs_reads are done instead of only one. Introduce
new call back get_cached_segment_base() for efficiency.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Add (set|get)_msr callbacks to x86_emulate_ops instead of calling
them directly.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Add (set|get)_dr callbacks to x86_emulate_ops instead of calling
them directly.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
cr0.ts may change between entries, so we copy cr0 to HOST_CR0 before each
entry. That is slow, so instead, set HOST_CR0 to have TS set unconditionally
(which is a safe value), and issue a clts() just before exiting vcpu context
if the task indeed owns the fpu.
Saves ~50 cycles/exit.
Signed-off-by: Avi Kivity <avi@redhat.com>
Although we always allocate a new dirty bitmap in x86's get_dirty_log(),
it is only used as a zero-source of copy_to_user() and freed right after
that when memslot is clean. This patch uses clear_user() instead of doing
this unnecessary zero-source allocation.
Performance improvement: as we can expect easily, the time needed to
allocate a bitmap is completely reduced. In my test, the improved ioctl
was about 4 to 10 times faster than the original one for clean slots.
Furthermore, reducing memory allocations and copies will produce good
effects to caches too.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
MSR_K6_EFER is unused, and MSR_K6_STAR is redundant with MSR_STAR.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1279371808-24804-1-git-send-email-brgerst@gmail.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (269 commits)
KVM: x86: Add missing locking to arch specific vcpu ioctls
KVM: PPC: Add missing vcpu_load()/vcpu_put() in vcpu ioctls
KVM: MMU: Segregate shadow pages with different cr0.wp
KVM: x86: Check LMA bit before set_efer
KVM: Don't allow lmsw to clear cr0.pe
KVM: Add cpuid.txt file
KVM: x86: Tell the guest we'll warn it about tsc stability
x86, paravirt: don't compute pvclock adjustments if we trust the tsc
x86: KVM guest: Try using new kvm clock msrs
KVM: x86: export paravirtual cpuid flags in KVM_GET_SUPPORTED_CPUID
KVM: x86: add new KVMCLOCK cpuid feature
KVM: x86: change msr numbers for kvmclock
x86, paravirt: Add a global synchronization point for pvclock
x86, paravirt: Enable pvclock flags in vcpu_time_info structure
KVM: x86: Inject #GP with the right rip on efer writes
KVM: SVM: Don't allow nested guest to VMMCALL into host
KVM: x86: Fix exception reinjection forced to true
KVM: Fix wallclock version writing race
KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_roots
KVM: VMX: enable VMXON check with SMX enabled (Intel TXT)
...
kvm_x86_ops->set_efer() would execute vcpu->arch.efer = efer, so the
checking of LMA bit didn't work.
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The current lmsw implementation allows the guest to clear cr0.pe, contrary
to the manual, which breaks EMM386.EXE.
Fix by ORing the old cr0.pe with lmsw's operand.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch puts up the flag that tells the guest that we'll warn it
about the tsc being trustworthy or not. By now, we also say
it is not.
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Right now, we were using individual KVM_CAP entities to communicate
userspace about which cpuids we support. This is suboptimal, since it
generates a delay between the feature arriving in the host, and
being available at the guest.
A much better mechanism is to list para features in KVM_GET_SUPPORTED_CPUID.
This makes userspace automatically aware of what we provide. And if we
ever add a new cpuid bit in the future, we have to do that again,
which create some complexity and delay in feature adoption.
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Avi pointed out a while ago that those MSRs falls into the pentium
PMU range. So the idea here is to add new ones, and after a while,
deprecate the old ones.
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch fixes a bug in the KVM efer-msr write path. If a
guest writes to a reserved efer bit the set_efer function
injects the #GP directly. The architecture dependent wrmsr
function does not see this, assumes success and advances the
rip. This results in a #GP in the guest with the wrong rip.
This patch fixes this by reporting efer write errors back to
the architectural wrmsr function.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The patch merged recently which allowed to mark an exception
as reinjected has a bug as it always marks the exception as
reinjected. This breaks nested-svm shadow-on-shadow
implementation.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Wallclock writing uses an unprotected global variable to hold the version;
this can cause one guest to interfere with another if both write their
wallclock at the same time.
Acked-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The recent changes to emulate string instructions without entering guest
mode exposed a bug where pending interrupts are not properly reflected
in ready_for_interrupt_injection.
The result is that userspace overwrites a previously queued interrupt,
when irqchip's are emulated in userspace.
Fix by always updating state before returning to userspace.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits)
perf tools: Add mode to build without newt support
perf symbols: symbol inconsistency message should be done only at verbose=1
perf tui: Add explicit -lslang option
perf options: Type check all the remaining OPT_ variants
perf options: Type check OPT_BOOLEAN and fix the offenders
perf options: Check v type in OPT_U?INTEGER
perf options: Introduce OPT_UINTEGER
perf tui: Add workaround for slang < 2.1.4
perf record: Fix bug mismatch with -c option definition
perf options: Introduce OPT_U64
perf tui: Add help window to show key associations
perf tui: Make <- exit menus too
perf newt: Add single key shortcuts for zoom into DSO and threads
perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed
perf newt: Fix the 'A'/'a' shortcut for annotate
perf newt: Make <- exit the ui_browser
x86, perf: P4 PMU - fix counters management logic
perf newt: Make <- zoom out filters
perf report: Report number of events, not samples
perf hist: Clarify events_stats fields usage
...
Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
This patch adds logic to kvm/x86 which allows to mark an
injected exception as reinjected. This allows to remove an
ugly hack from svm_complete_interrupts that prevented
exceptions from being reinjected at all in the nested case.
The hack was necessary because an reinjected exception into
the nested guest could cause a nested vmexit emulation. But
reinjected exceptions must not intercept. The downside of
the hack is that a exception that in injected could get
lost.
This patch fixes the problem and puts the code for it into
generic x86 files because. Nested-VMX will likely have the
same problem and could reuse the code.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch adds the get_supported_cpuid callback to
kvm_x86_ops. It will be used in do_cpuid_ent to delegate the
decission about some supported cpuid bits to the
architecture modules.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Since commit bf47a760f6, we no longer handle ptes with the global bit
set specially, so there is no reason to distinguish between shadow pages
created with cr4.gpe set and clear.
Such tracking is expensive when the guest toggles cr4.pge, so drop it.
Signed-off-by: Avi Kivity <avi@redhat.com>
emulator_task_switch() should return -1 for failure and 0 for success to
the caller, just like x86_emulate_insn() does.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When a fault triggers a task switch, the error code, if existent, has to
be pushed on the new task's stack. Implement the missing bits.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We can call kvm_mmu_pte_write() directly from
emulator_cmpxchg_emulated() instead of passing mmu_only down to
emulator_write_emulated_onepage() and call it there.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently both SVM and VMX have their own DR handling code. Move it to
x86.c.
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
MAXPHYADDR is derived from cpuid 0x80000008, but when that isn't present, we
get some random value.
Fix by checking first that cpuid 0x80000008 is supported.
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Log emulated instructions in ftrace, especially if they failed.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Make sure that rflags is committed only after successful instruction
emulation.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Unify all conditions that get us back into emulator after returning from
userspace.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently when string instruction is only partially complete we go back
to a guest mode, guest tries to reexecute instruction and exits again
and at this point emulation continues. Avoid all of this by restarting
instruction without going back to a guest mode, but return to a guest
mode each 1024 iterations to allow interrupt injection. Pending
exception causes immediate guest entry too.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently emulation is done outside of emulator so things like doing
ins/outs to/from mmio are broken it also makes it hard (if not impossible)
to implement single stepping in the future. The implementation in this
patch is not efficient since it exits to userspace for each IO while
previous implementation did 'ins' in batches. Further patch that
implements pio in string read ahead address this problem.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
in/out emulation is broken now. The breakage is different depending
on where IO device resides. If it is in userspace emulator reports
emulation failure since it incorrectly interprets kvm_emulate_pio()
return value. If IO device is in the kernel emulation of 'in' will do
nothing since kvm_emulate_pio() stores result directly into vcpu
registers, so emulator will overwrite result of emulation during
commit of shadowed register.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Eliminate the need to call back into KVM to get it from emulator.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Use this callback instead of directly call kvm function. Also rename
realmode_(set|get)_cr to emulator_(set|get)_cr since function has nothing
to do with real mode.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Mov reg, cr instruction doesn't change flags in any meaningful way, so
no need to update rflags after instruction execution.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Currently emulated atomic operations are immediately followed by a non-atomic
operation, so that kvm_mmu_pte_write() can be invoked. This updates the mmu
but undoes the whole point of doing things atomically.
Fix by only performing the atomic operation and the mmu update, and avoiding
the non-atomic write.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Once upon a time, locked operations were emulated while holding the mmu mutex.
Since mmu pages were write protected, it was safe to emulate the writes in
a non-atomic manner, since there could be no other writer, either in the
guest or in the kernel.
These days emulation takes place without holding the mmu spinlock, so the
write could be preempted by an unshadowing event, which exposes the page
to writes by the guest. This may cause corruption of guest page tables.
Fix by using an atomic cmpxchg for these operations.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If no irq chip in kernel, ioctl KVM_IRQ_LINE will return -EFAULT.
But I see in other place such as KVM_[GET|SET]IRQCHIP, -ENXIO is
return. So this patch used -ENXIO instead of -EFAULT.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This patch does:
- no need call tracepoint_synchronize_unregister() when kvm module
is unloaded since ftrace can handle it
- cleanup ftrace's macro
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
cpuid_update may operate VMCS, so vcpu_load() and vcpu_put()
should be called to ensure correctness.
Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
