Remove x86 KVM's fast invalidate mechanism, i.e. revert all patches
from the original series[1], now that all users of the fast invalidate
mechanism are gone.
This reverts commit 5304b8d37c.
[1] https://lkml.kernel.org/r/1369960590-14138-1-git-send-email-xiaoguangrong@linux.vnet.ibm.com
Cc: Xiao Guangrong <guangrong.xiao@gmail.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unwinding optimizations related to obsolete pages is a step towards
removing x86 KVM's fast invalidate mechanism, i.e. this is one part of
a revert all patches from the series that introduced the mechanism[1].
This reverts commit 365c886860.
[1] https://lkml.kernel.org/r/1369960590-14138-1-git-send-email-xiaoguangrong@linux.vnet.ibm.com
Cc: Xiao Guangrong <guangrong.xiao@gmail.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Revert back to a dedicated (and slower) mechanism for handling the
scenario where all MMIO shadow PTEs need to be zapped due to overflowing
the MMIO generation number. The MMIO generation scenario is almost
literally a one-in-a-million occurrence, i.e. is not a performance
sensitive scenario.
Restoring kvm_mmu_zap_mmio_sptes() leaves VM teardown as the only user
of kvm_mmu_invalidate_zap_all_pages() and paves the way for removing
the fast invalidate mechanism altogether.
This reverts commit a8eca9dcc6.
Cc: Xiao Guangrong <guangrong.xiao@gmail.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove x86 KVM's fast invalidate mechanism, i.e. revert all patches
from the original series[1].
Though not explicitly stated, for all intents and purposes the fast
invalidate mechanism was added to speed up the scenario where removing
a memslot, e.g. as part of accessing reading PCI ROM, caused KVM to
flush all shadow entries[1]. Now that the memslot case flushes only
shadow entries belonging to the memslot, i.e. doesn't use the fast
invalidate mechanism, the only remaining usage of the mechanism are
when the VM is being destroyed and when the MMIO generation rolls
over.
When a VM is being destroyed, either there are no active vcpus, i.e.
there's no lock contention, or the VM has ungracefully terminated, in
which case we want to reclaim its pages as quickly as possible, i.e.
not release the MMU lock if there are still CPUs executing in the VM.
The MMIO generation scenario is almost literally a one-in-a-million
occurrence, i.e. is not a performance sensitive scenario.
Given that lock-breaking is not desirable (VM teardown) or irrelevant
(MMIO generation overflow), remove the fast invalidate mechanism to
simplify the code (a small amount) and to discourage future code from
zapping all pages as using such a big hammer should be a last restort.
This reverts commit f6f8adeef5.
[1] https://lkml.kernel.org/r/1369960590-14138-1-git-send-email-xiaoguangrong@linux.vnet.ibm.com
Cc: Xiao Guangrong <guangrong.xiao@gmail.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_arch_memslots_updated() is at this point in time an x86-specific
hook for handling MMIO generation wraparound. x86 stashes 19 bits of
the memslots generation number in its MMIO sptes in order to avoid
full page fault walks for repeat faults on emulated MMIO addresses.
Because only 19 bits are used, wrapping the MMIO generation number is
possible, if unlikely. kvm_arch_memslots_updated() alerts x86 that
the generation has changed so that it can invalidate all MMIO sptes in
case the effective MMIO generation has wrapped so as to avoid using a
stale spte, e.g. a (very) old spte that was created with generation==0.
Given that the purpose of kvm_arch_memslots_updated() is to prevent
consuming stale entries, it needs to be called before the new generation
is propagated to memslots. Invalidating the MMIO sptes after updating
memslots means that there is a window where a vCPU could dereference
the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO
spte that was created with (pre-wrap) generation==0.
Fixes: e59dbe09f8 ("KVM: Introduce kvm_arch_memslots_updated()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Declaring the VCPU_REGS_* as enums allows for more robust C code, but it
prevents using the values in assembly files. Expliciting #define the
indices in an asm-friendly file to prepare for VMX moving its transition
code to a proper assembly file, but keep the enums for general usage.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
____kvm_handle_fault_on_reboot() provides a generic exception fixup
handler that is used to cleanly handle faults on VMX/SVM instructions
during reboot (or at least try to). If there isn't a reboot in
progress, ____kvm_handle_fault_on_reboot() treats any exception as
fatal to KVM and invokes kvm_spurious_fault(), which in turn generates
a BUG() to get a stack trace and die.
When it was originally added by commit 4ecac3fd6d ("KVM: Handle
virtualization instruction #UD faults during reboot"), the "call" to
kvm_spurious_fault() was handcoded as PUSH+JMP, where the PUSH'd value
is the RIP of the faulting instructing.
The PUSH+JMP trickery is necessary because the exception fixup handler
code lies outside of its associated function, e.g. right after the
function. An actual CALL from the .fixup code would show a slightly
bogus stack trace, e.g. an extra "random" function would be inserted
into the trace, as the return RIP on the stack would point to no known
function (and the unwinder will likely try to guess who owns the RIP).
Unfortunately, the JMP was replaced with a CALL when the macro was
reworked to not spin indefinitely during reboot (commit b7c4145ba2
"KVM: Don't spin on virt instruction faults during reboot"). This
causes the aforementioned behavior where a bogus function is inserted
into the stack trace, e.g. my builds like to blame free_kvm_area().
Revert the CALL back to a JMP. The changelog for commit b7c4145ba2
("KVM: Don't spin on virt instruction faults during reboot") contains
nothing that indicates the switch to CALL was deliberate. This is
backed up by the fact that the PUSH <insn RIP> was left intact.
Note that an alternative to the PUSH+JMP magic would be to JMP back
to the "real" code and CALL from there, but that would require adding
a JMP in the non-faulting path to avoid calling kvm_spurious_fault()
and would add no value, i.e. the stack trace would be the same.
Using CALL:
------------[ cut here ]------------
kernel BUG at /home/sean/go/src/kernel.org/linux/arch/x86/kvm/x86.c:356!
invalid opcode: 0000 [#1] SMP
CPU: 4 PID: 1057 Comm: qemu-system-x86 Not tainted 4.20.0-rc6+ #75
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:kvm_spurious_fault+0x5/0x10 [kvm]
Code: <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 49 89 fd 41
RSP: 0018:ffffc900004bbcc8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffffffffffff
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888273fd8000 R08: 00000000000003e8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000784 R12: ffffc90000371fb0
R13: 0000000000000000 R14: 000000026d763cf4 R15: ffff888273fd8000
FS: 00007f3d69691700(0000) GS:ffff888277800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f89bc56fe0 CR3: 0000000271a5a001 CR4: 0000000000362ee0
Call Trace:
free_kvm_area+0x1044/0x43ea [kvm_intel]
? vmx_vcpu_run+0x156/0x630 [kvm_intel]
? kvm_arch_vcpu_ioctl_run+0x447/0x1a40 [kvm]
? kvm_vcpu_ioctl+0x368/0x5c0 [kvm]
? kvm_vcpu_ioctl+0x368/0x5c0 [kvm]
? __set_task_blocked+0x38/0x90
? __set_current_blocked+0x50/0x60
? __fpu__restore_sig+0x97/0x490
? do_vfs_ioctl+0xa1/0x620
? __x64_sys_futex+0x89/0x180
? ksys_ioctl+0x66/0x70
? __x64_sys_ioctl+0x16/0x20
? do_syscall_64+0x4f/0x100
? entry_SYSCALL_64_after_hwframe+0x44/0xa9
Modules linked in: vhost_net vhost tap kvm_intel kvm irqbypass bridge stp llc
---[ end trace 9775b14b123b1713 ]---
Using JMP:
------------[ cut here ]------------
kernel BUG at /home/sean/go/src/kernel.org/linux/arch/x86/kvm/x86.c:356!
invalid opcode: 0000 [#1] SMP
CPU: 6 PID: 1067 Comm: qemu-system-x86 Not tainted 4.20.0-rc6+ #75
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:kvm_spurious_fault+0x5/0x10 [kvm]
Code: <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 49 89 fd 41
RSP: 0018:ffffc90000497cd0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffffffffffff
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88827058bd40 R08: 00000000000003e8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000784 R12: ffffc90000369fb0
R13: 0000000000000000 R14: 00000003c8fc6642 R15: ffff88827058bd40
FS: 00007f3d7219e700(0000) GS:ffff888277900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3d64001000 CR3: 0000000271c6b004 CR4: 0000000000362ee0
Call Trace:
vmx_vcpu_run+0x156/0x630 [kvm_intel]
? kvm_arch_vcpu_ioctl_run+0x447/0x1a40 [kvm]
? kvm_vcpu_ioctl+0x368/0x5c0 [kvm]
? kvm_vcpu_ioctl+0x368/0x5c0 [kvm]
? __set_task_blocked+0x38/0x90
? __set_current_blocked+0x50/0x60
? __fpu__restore_sig+0x97/0x490
? do_vfs_ioctl+0xa1/0x620
? __x64_sys_futex+0x89/0x180
? ksys_ioctl+0x66/0x70
? __x64_sys_ioctl+0x16/0x20
? do_syscall_64+0x4f/0x100
? entry_SYSCALL_64_after_hwframe+0x44/0xa9
Modules linked in: vhost_net vhost tap kvm_intel kvm irqbypass bridge stp llc
---[ end trace f9daedb85ab3ddba ]---
Fixes: b7c4145ba2 ("KVM: Don't spin on virt instruction faults during reboot")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The patch is to make kvm_set_spte_hva() return int and caller can
check return value to determine flush tlb or not.
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add flush range call back in the kvm_x86_ops and platform can use it
to register its associated function. The parameter "kvm_tlb_range"
accepts a single range and flush list which contains a list of ranges.
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Expose Intel Processor Trace to guest only when
the PT works in Host-Guest mode.
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Previously, the guest_fpu field was embedded in the kvm_vcpu_arch
struct. Unfortunately, the field is quite large, (e.g., 4352 bytes on my
current setup). This bloats the kvm_vcpu_arch struct for x86 into an
order 3 memory allocation, which can become a problem on overcommitted
machines. Thus, this patch moves the fpu state outside of the
kvm_vcpu_arch struct.
With this patch applied, the kvm_vcpu_arch struct is reduced to 15168
bytes for vmx on my setup when building the kernel with kvmconfig.
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Previously, x86's instantiation of 'struct kvm_vcpu_arch' added an fpu
field to save/restore fpu-related architectural state, which will differ
from kvm's fpu state. However, this is redundant to the 'struct fpu'
field, called fpu, embedded in the task struct, via the thread field.
Thus, this patch removes the user_fpu field from the kvm_vcpu_arch
struct and replaces it with the task struct's fpu field.
This change is significant because the fpu struct is actually quite
large. For example, on the system used to develop this patch, this
change reduces the size of the vcpu_vmx struct from 23680 bytes down to
19520 bytes, when building the kernel with kvmconfig. This reduction in
the size of the vcpu_vmx struct moves us closer to being able to
allocate the struct at order 2, rather than order 3.
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As a preparation to implementing Direct Mode for Hyper-V synthetic
timers switch to using stimer config definition from hyperv-tlfs.h.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The upcoming KVM_GET_SUPPORTED_HV_CPUID ioctl will need to return
Enlightened VMCS version in HYPERV_CPUID_NESTED_FEATURES.EAX when
it was enabled.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since commit e79f245dde ("X86/KVM: Properly update 'tsc_offset' to
represent the running guest"), vcpu->arch.tsc_offset meaning was
changed to always reflect the tsc_offset value set on active VMCS.
Regardless if vCPU is currently running L1 or L2.
However, above mentioned commit failed to also change
kvm_vcpu_write_tsc_offset() to set vcpu->arch.tsc_offset correctly.
This is because vmx_write_tsc_offset() could set the tsc_offset value
in active VMCS to given offset parameter *plus vmcs12->tsc_offset*.
However, kvm_vcpu_write_tsc_offset() just sets vcpu->arch.tsc_offset
to given offset parameter. Without taking into account the possible
addition of vmcs12->tsc_offset. (Same is true for SVM case).
Fix this issue by changing kvm_x86_ops->write_tsc_offset() to return
actually set tsc_offset in active VMCS and modify
kvm_vcpu_write_tsc_offset() to set returned value in
vcpu->arch.tsc_offset.
In addition, rename write_tsc_offset() callback to write_l1_tsc_offset()
to make it clear that it is meant to set L1 TSC offset.
Fixes: e79f245dde ("X86/KVM: Properly update 'tsc_offset' to represent the running guest")
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Leonid Shatz <leonid.shatz@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The per-VM capability KVM_CAP_EXCEPTION_PAYLOAD (to be introduced in a
later commit) adds the following fields to struct kvm_vcpu_events:
exception_has_payload, exception_payload, and exception.pending.
With this capability set, all of the details of vcpu->arch.exception,
including the payload for a pending exception, are reported to
userspace in response to KVM_GET_VCPU_EVENTS.
With this capability clear, the original ABI is preserved, and the
exception.injected field is set for either pending or injected
exceptions.
When userspace calls KVM_SET_VCPU_EVENTS with
KVM_CAP_EXCEPTION_PAYLOAD clear, exception.injected is no longer
translated to exception.pending. KVM_SET_VCPU_EVENTS can now only
establish a pending exception when KVM_CAP_EXCEPTION_PAYLOAD is set.
Reported-by: Jim Mattson <jmattson@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The payload associated with a #PF exception is the linear address of
the fault to be loaded into CR2 when the fault is delivered. The
payload associated with a #DB exception is a mask of the DR6 bits to
be set (or in the case of DR6.RTM, cleared) when the fault is
delivered. Add fields has_payload and payload to kvm_queued_exception
to track payloads for pending exceptions.
The new fields are introduced here, but for now, they are just cleared.
Reported-by: Jim Mattson <jmattson@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Enlightened VMCS is opt-in. The current version does not contain all
fields supported by nested VMX so we must not advertise the
corresponding VMX features if enlightened VMCS is enabled.
Userspace is given the enlightened VMCS version supported by KVM as
part of enabling KVM_CAP_HYPERV_ENLIGHTENED_VMCS. The version is to
be advertised to the nested hypervisor, currently done via a cpuid
leaf for Hyper-V.
Suggested-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MMU reconfiguration in init_kvm_tdp_mmu()/kvm_init_shadow_mmu() can be
avoided if the source data used to configure it didn't change; enhance
MMU extended role with the required fields and consolidate common code in
kvm_calc_mmu_role_common().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MMU re-initialization is expensive, in particular,
update_permission_bitmask() and update_pkru_bitmask() are.
Cache the data used to setup shadow EPT MMU and avoid full re-init when
it is unchanged.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In preparation to MMU reconfiguration avoidance we need a space to
cache source data. As this partially intersects with kvm_mmu_page_role,
create 64bit sized union kvm_mmu_role holding both base and extended data.
No functional change.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Just inline the contents into the sole caller, kvm_init_mmu is now
public.
Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
When EPT is used for nested guest we need to re-init MMU as shadow
EPT MMU (nested_ept_init_mmu_context() does that). When we return back
from L2 to L1 kvm_mmu_reset_context() in nested_vmx_load_cr3() resets
MMU back to normal TDP mode. Add a special 'guest_mmu' so we can use
separate root caches; the improved hit rate is not very important for
single vCPU performance, but it avoids contention on the mmu_lock for
many vCPUs.
On the nested CPUID benchmark, with 16 vCPUs, an L2->L1->L2 vmexit
goes from 42k to 26k cycles.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add an option to specify which MMU root we want to free. This will
be used when nested and non-nested MMUs for L1 are split.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
As a preparation to full MMU split between L1 and L2 make vcpu->arch.mmu
a pointer to the currently used mmu. For now, this is always
vcpu->arch.root_mmu. No functional change.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Regardless of whether your TLB is lush or not it still needs flushing.
Reported-by: Roman Kagan <rkagan@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In most common cases VP index of a vcpu matches its vcpu index. Userspace
is, however, free to set any mapping it wishes and we need to account for
that when we need to find a vCPU with a particular VP index. To keep search
algorithms optimal in both cases introduce 'num_mismatched_vp_indexes'
counter showing how many vCPUs with mismatching VP index we have. In case
the counter is zero we can assume vp_index == vcpu_idx.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, there are two definitions related to huge page, but a little bit
far from each other and seems loosely connected:
* KVM_NR_PAGE_SIZES defines the number of different size a page could map
* PT_MAX_HUGEPAGE_LEVEL means the maximum level of huge page
The number of different size a page could map equals the maximum level
of huge page, which is implied by current definition.
While current implementation may not be kind to readers and further
developers:
* KVM_NR_PAGE_SIZES looks like a stand alone definition at first sight
* in case we need to support more level, two places need to change
This patch tries to make these two definition more close, so that reader
and developer would feel more comfortable to manipulate.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
On a 64bits machine, struct is naturally aligned with 8 bytes. Since
kvm_mmu_page member *unsync* and *role* are less then 4 bytes, we can
rearrange the sequence to compace the struct.
As the comment shows, *role* and *gfn* are used to key the shadow page. In
order to keep the comment valid, this patch moves the *unsync* up and
exchange the position of *role* and *gfn*.
From /proc/slabinfo, it shows the size of kvm_mmu_page is 8 bytes less and
with one more object per slap after applying this patch.
# name <active_objs> <num_objs> <objsize> <objperslab>
kvm_mmu_page_header 0 0 168 24
kvm_mmu_page_header 0 0 160 25
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
According to volume 3 of the SDM, bits 63:15 and 12:4 of the exit
qualification field for debug exceptions are reserved (cleared to
0). However, the SDM is incorrect about bit 16 (corresponding to
DR6.RTM). This bit should be set if a debug exception (#DB) or a
breakpoint exception (#BP) occurred inside an RTM region while
advanced debugging of RTM transactional regions was enabled. Note that
this is the opposite of DR6.RTM, which "indicates (when clear) that a
debug exception (#DB) or breakpoint exception (#BP) occurred inside an
RTM region while advanced debugging of RTM transactional regions was
enabled."
There is still an issue with stale DR6 bits potentially being
misreported for the current debug exception. DR6 should not have been
modified before vectoring the #DB exception, and the "new DR6 bits"
should be available somewhere, but it was and they aren't.
Fixes: b96fb43977 ("KVM: nVMX: fixes to nested virt interrupt injection")
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add KVM_CAP_MSR_PLATFORM_INFO so that userspace can disable guest access
to reads of MSR_PLATFORM_INFO.
Disabling access to reads of this MSR gives userspace the control to "expose"
this platform-dependent information to guests in a clear way. As it exists
today, guests that read this MSR would get unpopulated information if userspace
hadn't already set it (and prior to this patch series, only the CPUID faulting
information could have been populated). This existing interface could be
confusing if guests don't handle the potential for incorrect/incomplete
information gracefully (e.g. zero reported for base frequency).
Signed-off-by: Drew Schmitt <dasch@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In case L1 do not intercept L2 HLT or enter L2 in HLT activity-state,
it is possible for a vCPU to be blocked while it is in guest-mode.
According to Intel SDM 26.6.5 Interrupt-Window Exiting and
Virtual-Interrupt Delivery: "These events wake the logical processor
if it just entered the HLT state because of a VM entry".
Therefore, if L1 enters L2 in HLT activity-state and L2 has a pending
deliverable interrupt in vmcs12->guest_intr_status.RVI, then the vCPU
should be waken from the HLT state and injected with the interrupt.
In addition, if while the vCPU is blocked (while it is in guest-mode),
it receives a nested posted-interrupt, then the vCPU should also be
waken and injected with the posted interrupt.
To handle these cases, this patch enhances kvm_vcpu_has_events() to also
check if there is a pending interrupt in L2 virtual APICv provided by
L1. That is, it evaluates if there is a pending virtual interrupt for L2
by checking RVI[7:4] > VPPR[7:4] as specified in Intel SDM 29.2.1
Evaluation of Pending Interrupts.
Note that this also handles the case of nested posted-interrupt by the
fact RVI is updated in vmx_complete_nested_posted_interrupt() which is
called from kvm_vcpu_check_block() -> kvm_arch_vcpu_runnable() ->
kvm_vcpu_running() -> vmx_check_nested_events() ->
vmx_complete_nested_posted_interrupt().
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A VMX preemption timer value of '0' is guaranteed to cause a VMExit
prior to the CPU executing any instructions in the guest. Use the
preemption timer (if it's supported) to trigger immediate VMExit
in place of the current method of sending a self-IPI. This ensures
that pending VMExit injection to L1 occurs prior to executing any
instructions in the guest (regardless of nesting level).
When deferring VMExit injection, KVM generates an immediate VMExit
from the (possibly nested) guest by sending itself an IPI. Because
hardware interrupts are blocked prior to VMEnter and are unblocked
(in hardware) after VMEnter, this results in taking a VMExit(INTR)
before any guest instruction is executed. But, as this approach
relies on the IPI being received before VMEnter executes, it only
works as intended when KVM is running as L0. Because there are no
architectural guarantees regarding when IPIs are delivered, when
running nested the INTR may "arrive" long after L2 is running e.g.
L0 KVM doesn't force an immediate switch to L1 to deliver an INTR.
For the most part, this unintended delay is not an issue since the
events being injected to L1 also do not have architectural guarantees
regarding their timing. The notable exception is the VMX preemption
timer[1], which is architecturally guaranteed to cause a VMExit prior
to executing any instructions in the guest if the timer value is '0'
at VMEnter. Specifically, the delay in injecting the VMExit causes
the preemption timer KVM unit test to fail when run in a nested guest.
Note: this approach is viable even on CPUs with a broken preemption
timer, as broken in this context only means the timer counts at the
wrong rate. There are no known errata affecting timer value of '0'.
[1] I/O SMIs also have guarantees on when they arrive, but I have
no idea if/how those are emulated in KVM.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
[Use a hook for SVM instead of leaving the default in x86.c - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Dan Carpenter reported that the untrusted data returns from kvm_register_read()
results in the following static checker warning:
arch/x86/kvm/lapic.c:576 kvm_pv_send_ipi()
error: buffer underflow 'map->phys_map' 's32min-s32max'
KVM guest can easily trigger this by executing the following assembly sequence
in Ring0:
mov $10, %rax
mov $0xFFFFFFFF, %rbx
mov $0xFFFFFFFF, %rdx
mov $0, %rsi
vmcall
As this will cause KVM to execute the following code-path:
vmx_handle_exit() -> handle_vmcall() -> kvm_emulate_hypercall() -> kvm_pv_send_ipi()
which will reach out-of-bounds access.
This patch fixes it by adding a check to kvm_pv_send_ipi() against map->max_apic_id,
ignoring destinations that are not present and delivering the rest. We also check
whether or not map->phys_map[min + i] is NULL since the max_apic_id is set to the
max apic id, some phys_map maybe NULL when apic id is sparse, especially kvm
unconditionally set max_apic_id to 255 to reserve enough space for any xAPIC ID.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Add second "if (min > map->max_apic_id)" to complete the fix. -Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
- Fix a VFP corruption in 32-bit guest
- Add missing cache invalidation for CoW pages
- Two small cleanups
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Merge tag 'kvm-arm-fixes-for-v4.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm
Fixes for KVM/ARM for Linux v4.19 v2:
- Fix a VFP corruption in 32-bit guest
- Add missing cache invalidation for CoW pages
- Two small cleanups
kvm_unmap_hva is long gone, and we only have kvm_unmap_hva_range to
deal with. Drop the now obsolete code.
Fixes: fb1522e099 ("KVM: update to new mmu_notifier semantic v2")
Cc: James Hogan <jhogan@kernel.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Allowing x86_emulate_instruction() to be called directly has led to
subtle bugs being introduced, e.g. not setting EMULTYPE_NO_REEXECUTE
in the emulation type. While most of the blame lies on re-execute
being opt-out, exporting x86_emulate_instruction() also exposes its
cr2 parameter, which may have contributed to commit d391f12070
("x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO
when running nested") using x86_emulate_instruction() instead of
emulate_instruction() because "hey, I have a cr2!", which in turn
introduced its EMULTYPE_NO_REEXECUTE bug.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Lack of the kvm_ prefix gives the impression that it's a VMX or SVM
specific function, and there's no conflict that prevents adding the
kvm_ prefix.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
retry_instruction() and reexecute_instruction() are a package deal,
i.e. there is no scenario where one is allowed and the other is not.
Merge their controlling emulation type flags to enforce this in code.
Name the combined flag EMULTYPE_ALLOW_RETRY to make it abundantly
clear that we are allowing re{try,execute} to occur, as opposed to
explicitly requesting retry of a previously failed instruction.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Re-execution of an instruction after emulation decode failure is
intended to be used only when emulating shadow page accesses. Invert
the flag to make allowing re-execution opt-in since that behavior is
by far in the minority.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Re-execution after an emulation decode failure is only intended to
handle a case where two or vCPUs race to write a shadowed page, i.e.
we should never re-execute an instruction as part of RSM emulation.
Add a new helper, kvm_emulate_instruction_from_buffer(), to support
emulating from a pre-defined buffer. This eliminates the last direct
call to x86_emulate_instruction() outside of kvm_mmu_page_fault(),
which means x86_emulate_instruction() can be unexported in a future
patch.
Fixes: 7607b71744 ("KVM: SVM: install RSM intercept")
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
For x86 this brings in PCID emulation and CR3 caching for shadow page
tables, nested VMX live migration, nested VMCS shadowing, an optimized
IPI hypercall, and some optimizations.
ARM will come next week.
There is a semantic conflict because tip also added an .init_platform
callback to kvm.c. Please keep the initializer from this branch,
and add a call to kvmclock_init (added by tip) inside kvm_init_platform
(added here).
Also, there is a backmerge from 4.18-rc6. This is because of a
refactoring that conflicted with a relatively late bugfix and
resulted in a particularly hellish conflict. Because the conflict
was only due to unfortunate timing of the bugfix, I backmerged and
rebased the refactoring rather than force the resolution on you.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull first set of KVM updates from Paolo Bonzini:
"PPC:
- minor code cleanups
x86:
- PCID emulation and CR3 caching for shadow page tables
- nested VMX live migration
- nested VMCS shadowing
- optimized IPI hypercall
- some optimizations
ARM will come next week"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (85 commits)
kvm: x86: Set highest physical address bits in non-present/reserved SPTEs
KVM/x86: Use CC_SET()/CC_OUT in arch/x86/kvm/vmx.c
KVM: X86: Implement PV IPIs in linux guest
KVM: X86: Add kvm hypervisor init time platform setup callback
KVM: X86: Implement "send IPI" hypercall
KVM/x86: Move X86_CR4_OSXSAVE check into kvm_valid_sregs()
KVM: x86: Skip pae_root shadow allocation if tdp enabled
KVM/MMU: Combine flushing remote tlb in mmu_set_spte()
KVM: vmx: skip VMWRITE of HOST_{FS,GS}_BASE when possible
KVM: vmx: skip VMWRITE of HOST_{FS,GS}_SEL when possible
KVM: vmx: always initialize HOST_{FS,GS}_BASE to zero during setup
KVM: vmx: move struct host_state usage to struct loaded_vmcs
KVM: vmx: compute need to reload FS/GS/LDT on demand
KVM: nVMX: remove a misleading comment regarding vmcs02 fields
KVM: vmx: rename __vmx_load_host_state() and vmx_save_host_state()
KVM: vmx: add dedicated utility to access guest's kernel_gs_base
KVM: vmx: track host_state.loaded using a loaded_vmcs pointer
KVM: vmx: refactor segmentation code in vmx_save_host_state()
kvm: nVMX: Fix fault priority for VMX operations
kvm: nVMX: Fix fault vector for VMX operation at CPL > 0
...
This patch is to provide a way for platforms to register hv tlb remote
flush callback and this helps to optimize operation of tlb flush
among vcpus for nested virtualization case.
Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It is a duplicate of X86_CR3_PCID_NOFLUSH. So just use that instead.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Adds support for storing multiple previous CR3/root_hpa pairs maintained
as an LRU cache, so that the lockless CR3 switch path can be used when
switching back to any of them.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This needs a minor bug fix. The updated patch is as follows.
Thanks,
Junaid
------------------------------------------------------------------------------
kvm_mmu_invlpg() and kvm_mmu_invpcid_gva() only need to flush the TLB
entries for the specific guest virtual address, instead of flushing all
TLB entries associated with the VM.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_mmu_free_roots() now takes a mask specifying which roots to free, so
that either one of the roots (active/previous) can be individually freed
when needed.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This allows invlpg() to be called using either the active root_hpa
or the prev_root_hpa.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When PCIDs are enabled, the MSb of the source operand for a MOV-to-CR3
instruction indicates that the TLB doesn't need to be flushed.
This change enables this optimization for MOV-to-CR3s in the guest
that have been intercepted by KVM for shadow paging and are handled
within the fast CR3 switch path.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Implement support for INVPCID in shadow paging mode as well.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The KVM_REQ_LOAD_CR3 request loads the hardware CR3 using the
current root_hpa.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When using shadow paging, a CR3 switch in the guest results in a VM Exit.
In the common case, that VM exit doesn't require much processing by KVM.
However, it does acquire the MMU lock, which can start showing signs of
contention under some workloads even on a 2 VCPU VM when the guest is
using KPTI. Therefore, we add a fast path that avoids acquiring the MMU
lock in the most common cases e.g. when switching back and forth between
the kernel and user mode CR3s used by KPTI with no guest page table
changes in between.
For now, this fast path is implemented only for 64-bit guests and hosts
to avoid the handling of PDPTEs, but it can be extended later to 32-bit
guests and/or hosts as well.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For nested virtualization L0 KVM is managing a bit of state for L2 guests,
this state can not be captured through the currently available IOCTLs. In
fact the state captured through all of these IOCTLs is usually a mix of L1
and L2 state. It is also dependent on whether the L2 guest was running at
the moment when the process was interrupted to save its state.
With this capability, there are two new vcpu ioctls: KVM_GET_NESTED_STATE
and KVM_SET_NESTED_STATE. These can be used for saving and restoring a VM
that is in VMX operation.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jim Mattson <jmattson@google.com>
[karahmed@ - rename structs and functions and make them ready for AMD and
address previous comments.
- handle nested.smm state.
- rebase & a bit of refactoring.
- Merge 7/8 and 8/8 into one patch. ]
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If the vCPU enters system management mode while running a nested guest,
RSM starts processing the vmentry while still in SMM. In that case,
however, the pages pointed to by the vmcs12 might be incorrectly
loaded from SMRAM. To avoid this, delay the handling of the pages
until just before the next vmentry. This is done with a new request
and a new entry in kvm_x86_ops, which we will be able to reuse for
nested VMX state migration.
Extracted from a patch by Jim Mattson and KarimAllah Ahmed.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When nested virtualization is in use, VMENTER operations from the nested
hypervisor into the nested guest will always be processed by the bare metal
hypervisor, and KVM's "conditional cache flushes" mode in particular does a
flush on nested vmentry. Therefore, include the "skip L1D flush on
vmentry" bit in KVM's suggested ARCH_CAPABILITIES setting.
Add the relevant Documentation.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The next patch in this series will have to make the definition of
irq_cpustat_t available to entering_irq().
Inclusion of asm/hardirq.h into asm/apic.h would cause circular header
dependencies like
asm/smp.h
asm/apic.h
asm/hardirq.h
linux/irq.h
linux/topology.h
linux/smp.h
asm/smp.h
or
linux/gfp.h
linux/mmzone.h
asm/mmzone.h
asm/mmzone_64.h
asm/smp.h
asm/apic.h
asm/hardirq.h
linux/irq.h
linux/irqdesc.h
linux/kobject.h
linux/sysfs.h
linux/kernfs.h
linux/idr.h
linux/gfp.h
and others.
This causes compilation errors because of the header guards becoming
effective in the second inclusion: symbols/macros that had been defined
before wouldn't be available to intermediate headers in the #include chain
anymore.
A possible workaround would be to move the definition of irq_cpustat_t
into its own header and include that from both, asm/hardirq.h and
asm/apic.h.
However, this wouldn't solve the real problem, namely asm/harirq.h
unnecessarily pulling in all the linux/irq.h cruft: nothing in
asm/hardirq.h itself requires it. Also, note that there are some other
archs, like e.g. arm64, which don't have that #include in their
asm/hardirq.h.
Remove the linux/irq.h #include from x86' asm/hardirq.h.
Fix resulting compilation errors by adding appropriate #includes to *.c
files as needed.
Note that some of these *.c files could be cleaned up a bit wrt. to their
set of #includes, but that should better be done from separate patches, if
at all.
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add the logic for flushing L1D on VMENTER. The flush depends on the static
key being enabled and the new l1tf_flush_l1d flag being set.
The flags is set:
- Always, if the flush module parameter is 'always'
- Conditionally at:
- Entry to vcpu_run(), i.e. after executing user space
- From the sched_in notifier, i.e. when switching to a vCPU thread.
- From vmexit handlers which are considered unsafe, i.e. where
sensitive data can be brought into L1D:
- The emulator, which could be a good target for other speculative
execution-based threats,
- The MMU, which can bring host page tables in the L1 cache.
- External interrupts
- Nested operations that require the MMU (see above). That is
vmptrld, vmptrst, vmclear,vmwrite,vmread.
- When handling invept,invvpid
[ tglx: Split out from combo patch and reduced to a single flag ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ARM: lazy context-switching of FPSIMD registers on arm64, "split"
regions for vGIC redistributor
* s390: cleanups for nested, clock handling, crypto, storage keys and
control register bits
* x86: many bugfixes, implement more Hyper-V super powers,
implement lapic_timer_advance_ns even when the LAPIC timer
is emulated using the processor's VMX preemption timer. Two
security-related bugfixes at the top of the branch.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"Small update for KVM:
ARM:
- lazy context-switching of FPSIMD registers on arm64
- "split" regions for vGIC redistributor
s390:
- cleanups for nested
- clock handling
- crypto
- storage keys
- control register bits
x86:
- many bugfixes
- implement more Hyper-V super powers
- implement lapic_timer_advance_ns even when the LAPIC timer is
emulated using the processor's VMX preemption timer.
- two security-related bugfixes at the top of the branch"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (79 commits)
kvm: fix typo in flag name
kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access
KVM: x86: pass kvm_vcpu to kvm_read_guest_virt and kvm_write_guest_virt_system
KVM: x86: introduce linear_{read,write}_system
kvm: nVMX: Enforce cpl=0 for VMX instructions
kvm: nVMX: Add support for "VMWRITE to any supported field"
kvm: nVMX: Restrict VMX capability MSR changes
KVM: VMX: Optimize tscdeadline timer latency
KVM: docs: nVMX: Remove known limitations as they do not exist now
KVM: docs: mmu: KVM support exposing SLAT to guests
kvm: no need to check return value of debugfs_create functions
kvm: Make VM ioctl do valloc for some archs
kvm: Change return type to vm_fault_t
KVM: docs: mmu: Fix link to NPT presentation from KVM Forum 2008
kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentation
KVM: x86: hyperv: declare KVM_CAP_HYPERV_TLBFLUSH capability
KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX implementation
KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} implementation
KVM: introduce kvm_make_vcpus_request_mask() API
KVM: x86: hyperv: do rep check for each hypercall separately
...
Implement HvFlushVirtualAddress{List,Space} hypercalls in a simplistic way:
do full TLB flush with KVM_REQ_TLB_FLUSH and kick vCPUs which are currently
IN_GUEST_MODE.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Expose the new virtualized architectural mechanism, VIRT_SSBD, for using
speculative store bypass disable (SSBD) under SVM. This will allow guests
to use SSBD on hardware that uses non-architectural mechanisms for enabling
SSBD.
[ tglx: Folded the migration fixup from Paolo Bonzini ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
L1 and L2 need to have disjoint mappings, so that L1's APIC access
page (under VMX) can be omitted from L2's mappings.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Previously, we toggled between SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE
and SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES, depending on whether or
not the EXTD bit was set in MSR_IA32_APICBASE. However, if the local
APIC is disabled, we should not set either of these APIC
virtualization control bits.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Extract the logic to free a root page in a separate function to avoid code
duplication in mmu_free_roots(). Also, change it to an exported function
i.e. kvm_mmu_free_roots().
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Update 'tsc_offset' on vmentry/vmexit of L2 guests to ensure that it always
captures the TSC_OFFSET of the running guest whether it is the L1 or L2
guest.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
[AMD changes, fix update_ia32_tsc_adjust_msr. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For exceptions & NMIs events, KVM code use the following
coding convention:
*) "pending" represents an event that should be injected to guest at
some point but it's side-effects have not yet occurred.
*) "injected" represents an event that it's side-effects have already
occurred.
However, interrupts don't conform to this coding convention.
All current code flows mark interrupt.pending when it's side-effects
have already taken place (For example, bit moved from LAPIC IRR to
ISR). Therefore, it makes sense to just rename
interrupt.pending to interrupt.injected.
This change follows logic of previous commit 664f8e26b0 ("KVM: X86:
Fix loss of exception which has not yet been injected") which changed
exception to follow this coding convention as well.
It is important to note that in case !lapic_in_kernel(vcpu),
interrupt.pending usage was and still incorrect.
In this case, interrrupt.pending can only be set using one of the
following ioctls: KVM_INTERRUPT, KVM_SET_VCPU_EVENTS and
KVM_SET_SREGS. Looking at how QEMU uses these ioctls, one can see that
QEMU uses them either to re-set an "interrupt.pending" state it has
received from KVM (via KVM_GET_VCPU_EVENTS interrupt.pending or
via KVM_GET_SREGS interrupt_bitmap) or by dispatching a new interrupt
from QEMU's emulated LAPIC which reset bit in IRR and set bit in ISR
before sending ioctl to KVM. So it seems that indeed "interrupt.pending"
in this case is also suppose to represent "interrupt.injected".
However, kvm_cpu_has_interrupt() & kvm_cpu_has_injectable_intr()
is misusing (now named) interrupt.injected in order to return if
there is a pending interrupt.
This leads to nVMX/nSVM not be able to distinguish if it should exit
from L2 to L1 on EXTERNAL_INTERRUPT on pending interrupt or should
re-inject an injected interrupt.
Therefore, add a FIXME at these functions for handling this issue.
This patch introduce no semantics change.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
hyperv.h is not part of uapi, there are no (known) users outside of kernel.
We are making changes to this file to match current Hyper-V Hypervisor
Top-Level Functional Specification (TLFS, see:
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs)
and we don't want to maintain backwards compatibility.
Move the file renaming to hyperv-tlfs.h to avoid confusing it with
mshyperv.h. In future, all definitions from TLFS should go to it and
all kernel objects should go to mshyperv.h or include/linux/hyperv.h.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Add struct kvm_svm, which is analagous to struct vcpu_svm, along with
a helper to_kvm_svm() to retrieve kvm_svm from a struct kvm *. Move
the SVM specific variables and struct definitions out of kvm_arch
and into kvm_svm.
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add struct kvm_vmx, which wraps struct kvm, and a helper to_kvm_vmx()
that retrieves 'struct kvm_vmx *' from 'struct kvm *'. Move the VMX
specific variables out of kvm_arch and into kvm_vmx.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add kvm_x86_ops->set_identity_map_addr and set ept_identity_map_addr
in VMX specific code so that ept_identity_map_addr can be moved out
of 'struct kvm_arch' in a future patch.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Define kvm_arch_[alloc|free]_vm in x86 as pass through functions
to new kvm_x86_ops vm_alloc and vm_free, and move the current
allocation logic as-is to SVM and VMX. Vendor specific alloc/free
functions set the stage for SVM/VMX wrappers of 'struct kvm',
which will allow us to move the growing number of SVM/VMX specific
member variables out of 'struct kvm_arch'.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When L1 IOAPIC redirection-table is written, a request of
KVM_REQ_SCAN_IOAPIC is set on all vCPUs. This is done such that
all vCPUs will now recalc their IOAPIC handled vectors and load
it to their EOI-exitmap.
However, it could be that one of the vCPUs is currently running
L2. In this case, load_eoi_exitmap() will be called which would
write to vmcs02->eoi_exit_bitmap, which is wrong because
vmcs02->eoi_exit_bitmap should always be equal to
vmcs12->eoi_exit_bitmap. Furthermore, at this point
KVM_REQ_SCAN_IOAPIC was already consumed and therefore we will
never update vmcs01->eoi_exit_bitmap. This could lead to remote_irr
of some IOAPIC level-triggered entry to remain set forever.
Fix this issue by delaying the load of EOI-exitmap to when vCPU
is running L1.
One may wonder why not just delay entire KVM_REQ_SCAN_IOAPIC
processing to when vCPU is running L1. This is done in order to handle
correctly the case where LAPIC & IO-APIC of L1 is pass-throughed into
L2. In this case, vmcs12->virtual_interrupt_delivery should be 0. In
current nVMX implementation, that results in
vmcs02->virtual_interrupt_delivery to also be 0. Thus,
vmcs02->eoi_exit_bitmap is not used. Therefore, every L2 EOI cause
a #VMExit into L0 (either on MSR_WRITE to x2APIC MSR or
APIC_ACCESS/APIC_WRITE/EPT_MISCONFIG to APIC MMIO page).
In order for such L2 EOI to be broadcasted, if needed, from LAPIC
to IO-APIC, vcpu->arch.ioapic_handled_vectors must be updated
while L2 is running. Therefore, patch makes sure to delay only the
loading of EOI-exitmap but not the update of
vcpu->arch.ioapic_handled_vectors.
Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow to disable pause loop exit/pause filtering on a per VM basis.
If some VMs have dedicated host CPUs, they won't be negatively affected
due to needlessly intercepted PAUSE instructions.
Thanks to Jan H. Schönherr's initial patch.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If host CPUs are dedicated to a VM, we can avoid VM exits on HLT.
This patch adds the per-VM capability to disable them.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allowing a guest to execute MWAIT without interception enables a guest
to put a (physical) CPU into a power saving state, where it takes
longer to return from than what may be desired by the host.
Don't give a guest that power over a host by default. (Especially,
since nothing prevents a guest from using MWAIT even when it is not
advertised via CPUID.)
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Access to VMware backdoor ports is done by one of the IN/OUT/INS/OUTS
instructions. These ports must be allowed access even if TSS I/O
permission bitmap don't allow it.
To handle this, VMX/SVM will be changed in future commits
to intercept #GP which was raised by such access and
handle it by calling x86 emulator to emulate instruction.
If it was one of these instructions, the x86 emulator already handles
it correctly (Since commit "KVM: x86: Always allow access to VMware
backdoor I/O ports") by not checking these ports against TSS I/O
permission bitmap.
One may wonder why checking for specific instructions is necessary
as we can just forward all #GPs to the x86 emulator.
There are multiple reasons for doing so:
1. We don't want the x86 emulator to be reached easily
by guest by just executing an instruction that raises #GP as that
exposes the x86 emulator as a bigger attack surface.
2. The x86 emulator is incomplete and therefore certain instructions
that can cause #GP cannot be emulated. Such an example is "INT x"
(opcode 0xcd) which reaches emulate_int() which can only emulate
the instruction if vCPU is in real-mode.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Next commits are going introduce support for accessing VMware backdoor
ports even though guest's TSS I/O permissions bitmap doesn't allow
access. This mimic VMware hypervisor behavior.
In order to support this, next commits will change VMX/SVM to
intercept #GP which was raised by such access and handle it by calling
the x86 emulator to emulate instruction. Since commit "KVM: x86:
Always allow access to VMware backdoor I/O ports", the x86 emulator
handles access to these I/O ports by not checking these ports against
the TSS I/O permission bitmap.
However, there could be cases that CPU rasies a #GP on instruction
that fails to be disassembled by the x86 emulator (Because of
incomplete implementation for example).
In those cases, we would like the #GP intercept to just forward #GP
as-is to guest as if there was no intercept to begin with.
However, current emulator code always queues #UD exception in case
emulator fails (including disassembly failures) which is not what is
wanted in this flow.
This commit addresses this issue by adding a new emulation_type flag
that will allow the #GP intercept handler to specify that it wishes
to be aware when instruction emulation fails and doesn't want #UD
exception to be queued.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add kvm_fast_pio() to consolidate duplicate code in VMX and SVM.
Unexport kvm_fast_pio_in() and kvm_fast_pio_out().
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Nested Hyper-V/Windows guest running on top of KVM will use TSC page
clocksource in two cases:
- L0 exposes invariant TSC (CPUID.80000007H:EDX[8]).
- L0 provides Hyper-V Reenlightenment support (CPUID.40000003H:EAX[13]).
Exposing invariant TSC effectively blocks migration to hosts with different
TSC frequencies, providing reenlightenment support will be needed when we
start migrating nested workloads.
Implement rudimentary support for reenlightenment MSRs. For now, these are
just read/write MSRs with no effect.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
In Hyper-V, the fast guest->host notification mechanism is the
SIGNAL_EVENT hypercall, with a single parameter of the connection ID to
signal.
Currently this hypercall incurs a user exit and requires the userspace
to decode the parameters and trigger the notification of the potentially
different I/O context.
To avoid the costly user exit, process this hypercall and signal the
corresponding eventfd in KVM, similar to ioeventfd. The association
between the connection id and the eventfd is established via the newly
introduced KVM_HYPERV_EVENTFD ioctl, and maintained in an
(srcu-protected) IDR.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[asm/hyperv.h changes approved by KY Srinivasan. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Linux (among the others) has checks to make sure that certain features
aren't enabled on a certain family/model/stepping if the microcode version
isn't greater than or equal to a known good version.
By exposing the real microcode version, we're preventing buggy guests that
don't check that they are running virtualized (i.e., they should trust the
hypervisor) from disabling features that are effectively not buggy.
Suggested-by: Filippo Sironi <sironi@amazon.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Provide a new KVM capability that allows bits within MSRs to be recognized
as features. Two new ioctls are added to the /dev/kvm ioctl routine to
retrieve the list of these MSRs and then retrieve their values. A kvm_x86_ops
callback is used to determine support for the listed MSR-based features.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Tweaked documentation. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Fix the following sparse warning by moving the prototype
of kvm_arch_mmu_notifier_invalidate_range() to linux/kvm_host.h .
CHECK arch/s390/kvm/../../../virt/kvm/kvm_main.c
arch/s390/kvm/../../../virt/kvm/kvm_main.c:138:13: warning: symbol 'kvm_arch_mmu_notifier_invalidate_range' was not declared. Should it be static?
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The efer_reload is never used since
commit 26bb0981b3 ("KVM: VMX: Use shared msr infrastructure"),
so remove it.
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This part of Secure Encrypted Virtualization (SEV) patch series focuses on KVM
changes required to create and manage SEV guests.
SEV is an extension to the AMD-V architecture which supports running encrypted
virtual machine (VMs) under the control of a hypervisor. Encrypted VMs have their
pages (code and data) secured such that only the guest itself has access to
unencrypted version. Each encrypted VM is associated with a unique encryption key;
if its data is accessed to a different entity using a different key the encrypted
guest's data will be incorrectly decrypted, leading to unintelligible data.
This security model ensures that hypervisor will no longer able to inspect or
alter any guest code or data.
The key management of this feature is handled by a separate processor known as
the AMD Secure Processor (AMD-SP) which is present on AMD SOCs. The SEV Key
Management Specification (see below) provides a set of commands which can be
used by hypervisor to load virtual machine keys through the AMD-SP driver.
The patch series adds a new ioctl in KVM driver (KVM_MEMORY_ENCRYPT_OP). The
ioctl will be used by qemu to issue SEV guest-specific commands defined in Key
Management Specification.
The following links provide additional details:
AMD Memory Encryption white paper:
http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf
AMD64 Architecture Programmer's Manual:
http://support.amd.com/TechDocs/24593.pdf
SME is section 7.10
SEV is section 15.34
SEV Key Management:
http://support.amd.com/TechDocs/55766_SEV-KM API_Specification.pdf
KVM Forum Presentation:
http://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf
SEV Guest BIOS support:
SEV support has been add to EDKII/OVMF BIOS
https://github.com/tianocore/edk2
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a new bool invalidate_gpa argument to kvm_x86_ops->tlb_flush,
it will be used by later patches to just flush guest tlb.
For VMX, this will use INVVPID instead of INVEPT, which will invalidate
combined mappings while keeping guest-physical mappings.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This MSR returns the number of #SMIs that occurred on CPU since
boot.
It was seen to be used frequently by ESXi guest.
Patch adds a new vcpu-arch specific var called smi_count to
save the number of #SMIs which occurred on CPU since boot.
It is exposed as a read-only MSR to guest (causing #GP
on wrmsr) in RDMSR/WRMSR emulation code.
MSR_SMI_COUNT is also added to emulated_msrs[] to make sure
user-space can save/restore it for migration purposes.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Bhavesh Davda <bhavesh.davda@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The User-Mode Instruction Prevention feature present in recent Intel
processor prevents a group of instructions (sgdt, sidt, sldt, smsw, and
str) from being executed with CPL > 0. Otherwise, a general protection
fault is issued.
UMIP instructions in general are also able to trigger vmexits, so we can
actually emulate UMIP on older processors. This commit sets up the
infrastructure so that kvm-intel.ko and kvm-amd.ko can set the UMIP
feature bit for CPUID even if the feature is not actually available
in hardware.
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add the CPUID bits, make the CR4.UMIP bit not reserved anymore, and
add UMIP support for instructions that are already emulated by KVM.
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Implementation of the unpinned APIC page didn't update the VMCS address
cache when invalidation was done through range mmu notifiers.
This became a problem when the page notifier was removed.
Re-introduce the arch-specific helper and call it from ...range_start.
Reported-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Fixes: 38b9917350 ("kvm: vmx: Implement set_apic_access_page_addr")
Fixes: 369ea8242c ("mm/rmap: update to new mmu_notifier semantic v2")
Cc: <stable@vger.kernel.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Tested-by: Wanpeng Li <wanpeng.li@hotmail.com>
Tested-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Currently, every time a VCPU is scheduled out, the host kernel will
first save the guest FPU/xstate context, then load the qemu userspace
FPU context, only to then immediately save the qemu userspace FPU
context back to memory. When scheduling in a VCPU, the same extraneous
FPU loads and saves are done.
This could be avoided by moving from a model where the guest FPU is
loaded and stored with preemption disabled, to a model where the
qemu userspace FPU is swapped out for the guest FPU context for
the duration of the KVM_RUN ioctl.
This is done under the VCPU mutex, which is also taken when other
tasks inspect the VCPU FPU context, so the code should already be
safe for this change. That should come as no surprise, given that
s390 already has this optimization.
This can fix a bug where KVM calls get_user_pages while owning the
FPU, and the file system ends up requesting the FPU again:
[258270.527947] __warn+0xcb/0xf0
[258270.527948] warn_slowpath_null+0x1d/0x20
[258270.527951] kernel_fpu_disable+0x3f/0x50
[258270.527953] __kernel_fpu_begin+0x49/0x100
[258270.527955] kernel_fpu_begin+0xe/0x10
[258270.527958] crc32c_pcl_intel_update+0x84/0xb0
[258270.527961] crypto_shash_update+0x3f/0x110
[258270.527968] crc32c+0x63/0x8a [libcrc32c]
[258270.527975] dm_bm_checksum+0x1b/0x20 [dm_persistent_data]
[258270.527978] node_prepare_for_write+0x44/0x70 [dm_persistent_data]
[258270.527985] dm_block_manager_write_callback+0x41/0x50 [dm_persistent_data]
[258270.527988] submit_io+0x170/0x1b0 [dm_bufio]
[258270.527992] __write_dirty_buffer+0x89/0x90 [dm_bufio]
[258270.527994] __make_buffer_clean+0x4f/0x80 [dm_bufio]
[258270.527996] __try_evict_buffer+0x42/0x60 [dm_bufio]
[258270.527998] dm_bufio_shrink_scan+0xc0/0x130 [dm_bufio]
[258270.528002] shrink_slab.part.40+0x1f5/0x420
[258270.528004] shrink_node+0x22c/0x320
[258270.528006] do_try_to_free_pages+0xf5/0x330
[258270.528008] try_to_free_pages+0xe9/0x190
[258270.528009] __alloc_pages_slowpath+0x40f/0xba0
[258270.528011] __alloc_pages_nodemask+0x209/0x260
[258270.528014] alloc_pages_vma+0x1f1/0x250
[258270.528017] do_huge_pmd_anonymous_page+0x123/0x660
[258270.528021] handle_mm_fault+0xfd3/0x1330
[258270.528025] __get_user_pages+0x113/0x640
[258270.528027] get_user_pages+0x4f/0x60
[258270.528063] __gfn_to_pfn_memslot+0x120/0x3f0 [kvm]
[258270.528108] try_async_pf+0x66/0x230 [kvm]
[258270.528135] tdp_page_fault+0x130/0x280 [kvm]
[258270.528149] kvm_mmu_page_fault+0x60/0x120 [kvm]
[258270.528158] handle_ept_violation+0x91/0x170 [kvm_intel]
[258270.528162] vmx_handle_exit+0x1ca/0x1400 [kvm_intel]
No performance changes were detected in quick ping-pong tests on
my 4 socket system, which is expected since an FPU+xstate load is
on the order of 0.1us, while ping-ponging between CPUs is on the
order of 20us, and somewhat noisy.
Cc: stable@vger.kernel.org
Signed-off-by: Rik van Riel <riel@redhat.com>
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Fixed a bug where reset_vcpu called put_fpu without preceding load_fpu,
which happened inside from KVM_CREATE_VCPU ioctl. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The SEV memory encryption engine uses a tweak such that two identical
plaintext pages at different location will have different ciphertext.
So swapping or moving ciphertext of two pages will not result in
plaintext being swapped. Relocating (or migrating) physical backing
pages for a SEV guest will require some additional steps. The current SEV
key management spec does not provide commands to swap or migrate (move)
ciphertext pages. For now, we pin the guest memory registered through
KVM_MEMORY_ENCRYPT_REG_REGION ioctl.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
The command is used for encrypting the guest memory region using the VM
encryption key (VEK) created during KVM_SEV_LAUNCH_START.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
The KVM_SEV_LAUNCH_START command is used to create a memory encryption
context within the SEV firmware. In order to do so, the guest owner
should provide the guest's policy, its public Diffie-Hellman (PDH) key
and session information. The command implements the LAUNCH_START flow
defined in SEV spec Section 6.2.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
The command initializes the SEV platform context and allocates a new ASID
for this guest from the SEV ASID pool. The firmware must be initialized
before we issue any guest launch commands to create a new memory encryption
context.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
If hardware supports memory encryption then KVM_MEMORY_ENCRYPT_REG_REGION
and KVM_MEMORY_ENCRYPT_UNREG_REGION ioctl's can be used by userspace to
register/unregister the guest memory regions which may contain the encrypted
data (e.g guest RAM, PCI BAR, SMRAM etc).
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
If the hardware supports memory encryption then the
KVM_MEMORY_ENCRYPT_OP ioctl can be used by qemu to issue a platform
specific memory encryption commands.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
In case of instruction-decode failure or emulation failure,
x86_emulate_instruction() will call reexecute_instruction() which will
attempt to use the cr2 value passed to x86_emulate_instruction().
However, when x86_emulate_instruction() is called from
emulate_instruction(), cr2 is not passed (passed as 0) and therefore
it doesn't make sense to execute reexecute_instruction() logic at all.
Fixes: 51d8b66199 ("KVM: cleanup emulate_instruction")
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Common:
- Python 3 support in kvm_stat
- Accounting of slabs to kmemcg
ARM:
- Optimized arch timer handling for KVM/ARM
- Improvements to the VGIC ITS code and introduction of an ITS reset
ioctl
- Unification of the 32-bit fault injection logic
- More exact external abort matching logic
PPC:
- Support for running hashed page table (HPT) MMU mode on a host that
is using the radix MMU mode; single threaded mode on POWER 9 is
added as a pre-requisite
- Resolution of merge conflicts with the last second 4.14 HPT fixes
- Fixes and cleanups
s390:
- Some initial preparation patches for exitless interrupts and crypto
- New capability for AIS migration
- Fixes
x86:
- Improved emulation of LAPIC timer mode changes, MCi_STATUS MSRs, and
after-reset state
- Refined dependencies for VMX features
- Fixes for nested SMI injection
- A lot of cleanups
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Merge tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Radim Krčmář:
"First batch of KVM changes for 4.15
Common:
- Python 3 support in kvm_stat
- Accounting of slabs to kmemcg
ARM:
- Optimized arch timer handling for KVM/ARM
- Improvements to the VGIC ITS code and introduction of an ITS reset
ioctl
- Unification of the 32-bit fault injection logic
- More exact external abort matching logic
PPC:
- Support for running hashed page table (HPT) MMU mode on a host that
is using the radix MMU mode; single threaded mode on POWER 9 is
added as a pre-requisite
- Resolution of merge conflicts with the last second 4.14 HPT fixes
- Fixes and cleanups
s390:
- Some initial preparation patches for exitless interrupts and crypto
- New capability for AIS migration
- Fixes
x86:
- Improved emulation of LAPIC timer mode changes, MCi_STATUS MSRs,
and after-reset state
- Refined dependencies for VMX features
- Fixes for nested SMI injection
- A lot of cleanups"
* tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (89 commits)
KVM: s390: provide a capability for AIS state migration
KVM: s390: clear_io_irq() requests are not expected for adapter interrupts
KVM: s390: abstract conversion between isc and enum irq_types
KVM: s390: vsie: use common code functions for pinning
KVM: s390: SIE considerations for AP Queue virtualization
KVM: s390: document memory ordering for kvm_s390_vcpu_wakeup
KVM: PPC: Book3S HV: Cosmetic post-merge cleanups
KVM: arm/arm64: fix the incompatible matching for external abort
KVM: arm/arm64: Unify 32bit fault injection
KVM: arm/arm64: vgic-its: Implement KVM_DEV_ARM_ITS_CTRL_RESET
KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET
KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared
KVM: arm/arm64: vgic-its: New helper functions to free the caches
KVM: arm/arm64: vgic-its: Remove kvm_its_unmap_device
arm/arm64: KVM: Load the timer state when enabling the timer
KVM: arm/arm64: Rework kvm_timer_should_fire
KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate
KVM: arm/arm64: Avoid phys timer emulation in vcpu entry/exit
KVM: arm/arm64: Move phys_timer_emulate function
KVM: arm/arm64: Use kvm_arm_timer_set/get_reg for guest register traps
...
Commit 05cade71cf ("KVM: nSVM: fix SMI injection in guest mode") made
KVM mask SMI if GIF=0 but it didn't do anything to unmask it when GIF is
enabled.
The issue manifests for me as a significantly longer boot time of Windows
guests when running with SMM-enabled OVMF.
This commit fixes it by intercepting STGI instead of requesting immediate
exit if the reason why SMM was masked is GIF.
Fixes: 05cade71cf ("KVM: nSVM: fix SMI injection in guest mode")
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
