Commit Graph

95052 Commits

Author SHA1 Message Date
Bandan Das
3573e22cfe KVM: nVMX: additional checks on vmxon region
Currently, the vmxon region isn't used in the nested case.
However, according to the spec, the vmxon instruction performs
additional sanity checks on this region and the associated
pointer. Modify emulated vmxon to better adhere to the spec
requirements

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-06 19:00:27 +02:00
Bandan Das
19677e32fe KVM: nVMX: rearrange get_vmx_mem_address
Our common function for vmptr checks (in 2/4) needs to fetch
the memory address

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-06 18:59:57 +02:00
Paolo Bonzini
2ce316f0b9 1. Fixes an error return code for the breakpoint setup
2. External interrupt fixes
 2.1. Some interrupt conditions like cpu timer or clock comparator
 stay pending even after the interrupt is injected. If the external
 new PSW is enabled for interrupts this will result in an endless
 loop. Usually this indicates a programming error in the guest OS.
 Lets detect such situations and go to userspace. We will provide
 a QEMU patch that sets the guest in panicked/crashed state to avoid
 wasting CPU cycles.
 2.2 Resend external interrupts back to the guest if the HW could
 not do it.
 -
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Merge tag 'kvm-s390-20140506' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next

1. Fixes an error return code for the breakpoint setup

2. External interrupt fixes
2.1. Some interrupt conditions like cpu timer or clock comparator
stay pending even after the interrupt is injected. If the external
new PSW is enabled for interrupts this will result in an endless
loop. Usually this indicates a programming error in the guest OS.
Lets detect such situations and go to userspace. We will provide
a QEMU patch that sets the guest in panicked/crashed state to avoid
wasting CPU cycles.
2.2 Resend external interrupts back to the guest if the HW could
not do it.
-
2014-05-06 17:20:37 +02:00
Thomas Huth
f14d82e06a KVM: s390: Fix external interrupt interception
The external interrupt interception can only occur in rare cases, e.g.
when the PSW of the interrupt handler has a bad value. The old handler
for this interception simply ignored these events (except for increasing
the exit_external_interrupt counter), but for proper operation we either
have to inject the interrupts manually or we should drop to userspace in
case of errors.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-06 14:58:10 +02:00
Thomas Huth
e029ae5b78 KVM: s390: Add clock comparator and CPU timer IRQ injection
Add an interface to inject clock comparator and CPU timer interrupts
into the guest. This is needed for handling the external interrupt
interception.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-06 14:58:05 +02:00
Dan Carpenter
fcc9aec3de KVM: s390: return -EFAULT if copy_from_user() fails
When copy_from_user() fails, this code returns the number of bytes
remaining instead of a negative error code.  The positive number is
returned to the user but otherwise it is harmless.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-06 14:57:59 +02:00
Ulrich Obergfell
1171903d89 KVM: x86: improve the usability of the 'kvm_pio' tracepoint
This patch moves the 'kvm_pio' tracepoint to emulator_pio_in_emulated()
and emulator_pio_out_emulated(), and it adds an argument (a pointer to
the 'pio_data'). A single 8-bit or 16-bit or 32-bit data item is fetched
from 'pio_data' (depending on 'size'), and the value is included in the
trace record ('val'). If 'count' is greater than one, this is indicated
by the string "(...)" in the trace output.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-05 22:42:05 +02:00
Paolo Bonzini
57b5981cd3 1. Guest handling fixes
The handling of MVPG, PFMF and Test Block is fixed to better follow
 the architecture. None of these fixes is critical for any current
 Linux guests, but let's play safe.
 
 2. Optimization for single CPU guests
 We can enable the IBS facility if only one VCPU is running (!STOPPED
 state). We also enable this optimization for guest > 1 VCPU as soon
 as all but one VCPU is in stopped state. Thus will help guests that
 have tools like cpuplugd (from s390-utils) that do dynamic offline/
 online of CPUs.
 
 3. NOTES
 There is one non-s390 change in include/linux/kvm_host.h that
 introduces 2 defines for VCPU requests:
 define KVM_REQ_ENABLE_IBS        23
 define KVM_REQ_DISABLE_IBS       24
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Merge tag 'kvm-s390-20140429' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next

1. Guest handling fixes
The handling of MVPG, PFMF and Test Block is fixed to better follow
the architecture. None of these fixes is critical for any current
Linux guests, but let's play safe.

2. Optimization for single CPU guests
We can enable the IBS facility if only one VCPU is running (!STOPPED
state). We also enable this optimization for guest > 1 VCPU as soon
as all but one VCPU is in stopped state. Thus will help guests that
have tools like cpuplugd (from s390-utils) that do dynamic offline/
online of CPUs.

3. NOTES
There is one non-s390 change in include/linux/kvm_host.h that
introduces 2 defines for VCPU requests:
define KVM_REQ_ENABLE_IBS        23
define KVM_REQ_DISABLE_IBS       24
2014-04-30 12:29:41 +02:00
Marcelo Tosatti
e4c9a5a175 KVM: x86: expose invariant tsc cpuid bit (v2)
Invariant TSC is a property of TSC, no additional
support code necessary.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-04-29 15:22:43 +02:00
David Hildenbrand
8ad3575517 KVM: s390: enable IBS for single running VCPUs
This patch enables the IBS facility when a single VCPU is running.
The facility is dynamically turned on/off as soon as other VCPUs
enter/leave the stopped state.

When this facility is operating, some instructions can be executed
faster for single-cpu guests.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-29 15:01:54 +02:00
David Hildenbrand
6852d7b69b KVM: s390: introduce kvm_s390_vcpu_{start,stop}
This patch introduces two new functions to set/clear the CPUSTAT_STOPPED bit and
makes use of it at all applicable places. These functions prepare the additional
execution of code when starting/stopping a vcpu.

The CPUSTAT_STOPPED bit should not be touched outside of these functions.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-29 15:01:54 +02:00
Thomas Huth
e45efa28e5 KVM: s390: Add low-address protection to TEST BLOCK
TEST BLOCK is also subject to the low-address protection, so we need
to check the destination address in our handler.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-29 15:01:53 +02:00
Thomas Huth
fb34c60365 KVM: s390: Fixes for PFMF
Add a check for low-address protection to the PFMF handler and
convert real-addresses to absolute if necessary, as it is defined
in the Principles of Operations specification.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-29 15:01:53 +02:00
Thomas Huth
f8232c8cf7 KVM: s390: Add a function for checking the low-address protection
The s390 architecture has a special protection mechanism that can
be used to prevent write access to the vital data in the low-core
memory area. This patch adds a new helper function that can be used
to check for such write accesses and in case of protection, it also
sets up the exception data accordingly.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-29 15:01:52 +02:00
Thomas Huth
9a558ee3cc KVM: s390: Handle MVPG partial execution interception
When the guest executes the MVPG instruction with DAT disabled,
and the source or destination page is not mapped in the host,
the so-called partial execution interception occurs. We need to
handle this event by setting up a mapping for the corresponding
user pages.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-29 15:01:51 +02:00
Xiao Guangrong
198c74f43f KVM: MMU: flush tlb out of mmu lock when write-protect the sptes
Now we can flush all the TLBs out of the mmu lock without TLB corruption when
write-proect the sptes, it is because:
- we have marked large sptes readonly instead of dropping them that means we
  just change the spte from writable to readonly so that we only need to care
  the case of changing spte from present to present (changing the spte from
  present to nonpresent will flush all the TLBs immediately), in other words,
  the only case we need to care is mmu_spte_update()

- in mmu_spte_update(), we haved checked
  SPTE_HOST_WRITEABLE | PTE_MMU_WRITEABLE instead of PT_WRITABLE_MASK, that
  means it does not depend on PT_WRITABLE_MASK anymore

Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:49:52 -03:00
Xiao Guangrong
7f31c9595e KVM: MMU: flush tlb if the spte can be locklessly modified
Relax the tlb flush condition since we will write-protect the spte out of mmu
lock. Note lockless write-protection only marks the writable spte to readonly
and the spte can be writable only if both SPTE_HOST_WRITEABLE and
SPTE_MMU_WRITEABLE are set (that are tested by spte_is_locklessly_modifiable)

This patch is used to avoid this kind of race:

      VCPU 0                         VCPU 1
lockless wirte protection:
      set spte.w = 0
                                 lock mmu-lock

                                 write protection the spte to sync shadow page,
                                 see spte.w = 0, then without flush tlb

				 unlock mmu-lock

                                 !!! At this point, the shadow page can still be
                                     writable due to the corrupt tlb entry
     Flush all TLB

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:49:51 -03:00
Xiao Guangrong
c126d94f2c KVM: MMU: lazily drop large spte
Currently, kvm zaps the large spte if write-protected is needed, the later
read can fault on that spte. Actually, we can make the large spte readonly
instead of making them un-present, the page fault caused by read access can
be avoided

The idea is from Avi:
| As I mentioned before, write-protecting a large spte is a good idea,
| since it moves some work from protect-time to fault-time, so it reduces
| jitter.  This removes the need for the return value.

This version has fixed the issue reported in 6b73a9606, the reason of that
issue is that fast_page_fault() directly sets the readonly large spte to
writable but only dirty the first page into the dirty-bitmap that means
other pages are missed. Fixed it by only the normal sptes (on the
PT_PAGE_TABLE_LEVEL level) can be fast fixed

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:49:50 -03:00
Xiao Guangrong
92a476cbfc KVM: MMU: properly check last spte in fast_page_fault()
Using sp->role.level instead of @level since @level is not got from the
page table hierarchy

There is no issue in current code since the fast page fault currently only
fixes the fault caused by dirty-log that is always on the last level
(level = 1)

This patch makes the code more readable and avoids potential issue in the
further development

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:49:49 -03:00
Xiao Guangrong
a086f6a1eb Revert "KVM: Simplify kvm->tlbs_dirty handling"
This reverts commit 5befdc385d.

Since we will allow flush tlb out of mmu-lock in the later
patch

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:49:48 -03:00
Nadav Amit
42bf549f3c KVM: x86: Processor mode may be determined incorrectly
If EFER.LMA is off, cs.l does not determine execution mode.
Currently, the emulation engine assumes differently.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:47:00 -03:00
Nadav Amit
e6e39f0438 KVM: x86: IN instruction emulation should ignore REP-prefix
The IN instruction is not be affected by REP-prefix as INS is.  Therefore, the
emulation should ignore the REP prefix as well.  The current emulator
implementation tries to perform writeback when IN instruction with REP-prefix
is emulated. This causes it to perform wrong memory write or spurious #GP
exception to be injected to the guest.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:46:59 -03:00
Nadav Amit
346874c950 KVM: x86: Fix CR3 reserved bits
According to Intel specifications, PAE and non-PAE does not have any reserved
bits.  In long-mode, regardless to PCIDE, only the high bits (above the
physical address) are reserved.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:46:57 -03:00
Nadav Amit
671bd9934a KVM: x86: Fix wrong/stuck PMU when guest does not use PMI
If a guest enables a performance counter but does not enable PMI, the
hypervisor currently does not reprogram the performance counter once it
overflows.  As a result the host performance counter is kept with the original
sampling period which was configured according to the value of the guest's
counter when the counter was enabled.

Such behaviour can cause very bad consequences. The most distrubing one can
cause the guest not to make any progress at all, and keep exiting due to host
PMI before any guest instructions is exeucted. This situation occurs when the
performance counter holds a very high value when the guest enables the
performance counter. As a result the host's sampling period is configured to be
very short. The host then never reconfigures the sampling period and get stuck
at entry->PMI->exit loop. We encountered such a scenario in our experiments.

The solution is to reprogram the counter even if the guest does not use PMI.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-23 17:46:52 -03:00
Bandan Das
e0ba1a6ffc KVM: nVMX: Advertise support for interrupt acknowledgement
Some Type 1 hypervisors such as XEN won't enable VMX without it present

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22 18:41:34 -03:00
Bandan Das
77b0f5d67f KVM: nVMX: Ack and write vector info to intr_info if L1 asks us to
This feature emulates the "Acknowledge interrupt on exit" behavior.
We can safely emulate it for L1 to run L2 even if L0 itself has it
disabled (to run L1).

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22 18:41:33 -03:00
Bandan Das
4b85507860 KVM: nVMX: Don't advertise single context invalidation for invept
For single context invalidation, we fall through to global
invalidation in handle_invept() except for one case - when
the operand supplied by L1 is different from what we have in
vmcs12. However, typically hypervisors will only call invept
for the currently loaded eptp, so the condition will
never be true.

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22 18:41:28 -03:00
Huw Davies
fd2a445a94 KVM: VMX: Advance rip to after an ICEBP instruction
When entering an exception after an ICEBP, the saved instruction
pointer should point to after the instruction.

This fixes the bug here: https://bugs.launchpad.net/qemu/+bug/1119686

Signed-off-by: Huw Davies <huw@codeweavers.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2014-04-22 18:37:43 -03:00
Marcelo Tosatti
63b5cf04f4 Lazy storage key handling
-------------------------
 Linux does not use the ACC and F bits of the storage key. Newer Linux
 versions also do not use the storage keys for dirty and reference
 tracking. We can optimize the guest handling for those guests for faults
 as well as page-in and page-out by simply not caring about the guest
 visible storage key. We trap guest storage key instruction to enable
 those keys only on demand.
 
 Migration bitmap
 
 Until now s390 never provided a proper dirty bitmap.  Let's provide a
 proper migration bitmap for s390. We also change the user dirty tracking
 to a fault based mechanism. This makes the host completely independent
 from the storage keys. Long term this will allow us to back guest memory
 with large pages.
 
 per-VM device attributes
 ------------------------
 To avoid the introduction of new ioctls, let's provide the
 attribute semanantic also on the VM-"device".
 
 Userspace controlled CMMA
 -------------------------
 The CMMA assist is changed from "always on" to "on if requested" via
 per-VM device attributes. In addition a callback to reset all usage
 states is provided.
 
 Proper guest DAT handling for intercepts
 ----------------------------------------
 While instructions handled by SIE take care of all addressing aspects,
 KVM/s390 currently does not care about guest address translation of
 intercepts. This worked out fine, because
 - the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real
  for all pages up to memory size
 - intercepts happen only for a small amount of cases
 - all of these intercepts happen to be in the kernel text for current
   distros
 
 Of course we need to be better for other intercepts, kernel modules etc.
 We provide the infrastructure and rework all in-kernel intercepts to work
 on logical addresses (paging etc) instead of real ones. The code has
 been running internally for several months now, so it is time for going
 public.
 
 GDB support
 -----------
 We provide breakpoints, single stepping and watchpoints.
 
 Fixes/Cleanups
 --------------
 - Improve program check delivery
 - Factor out the handling of transactional memory  on program checks
 - Use the existing define __LC_PGM_TDB
 - Several cleanups in the lowcore structure
 - Documentation
 
 NOTES
 -----
 - All patches touching base s390 are either ACKed or written by the s390
   maintainers
 - One base KVM patch "KVM: add kvm_is_error_gpa() helper"
 - One patch introduces the notion of VM device attributes
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Merge tag 'kvm-s390-20140422' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into queue

Lazy storage key handling
-------------------------
Linux does not use the ACC and F bits of the storage key. Newer Linux
versions also do not use the storage keys for dirty and reference
tracking. We can optimize the guest handling for those guests for faults
as well as page-in and page-out by simply not caring about the guest
visible storage key. We trap guest storage key instruction to enable
those keys only on demand.

Migration bitmap

Until now s390 never provided a proper dirty bitmap.  Let's provide a
proper migration bitmap for s390. We also change the user dirty tracking
to a fault based mechanism. This makes the host completely independent
from the storage keys. Long term this will allow us to back guest memory
with large pages.

per-VM device attributes
------------------------
To avoid the introduction of new ioctls, let's provide the
attribute semanantic also on the VM-"device".

Userspace controlled CMMA
-------------------------
The CMMA assist is changed from "always on" to "on if requested" via
per-VM device attributes. In addition a callback to reset all usage
states is provided.

Proper guest DAT handling for intercepts
----------------------------------------
While instructions handled by SIE take care of all addressing aspects,
KVM/s390 currently does not care about guest address translation of
intercepts. This worked out fine, because
- the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real
 for all pages up to memory size
- intercepts happen only for a small amount of cases
- all of these intercepts happen to be in the kernel text for current
  distros

Of course we need to be better for other intercepts, kernel modules etc.
We provide the infrastructure and rework all in-kernel intercepts to work
on logical addresses (paging etc) instead of real ones. The code has
been running internally for several months now, so it is time for going
public.

GDB support
-----------
We provide breakpoints, single stepping and watchpoints.

Fixes/Cleanups
--------------
- Improve program check delivery
- Factor out the handling of transactional memory  on program checks
- Use the existing define __LC_PGM_TDB
- Several cleanups in the lowcore structure
- Documentation

NOTES
-----
- All patches touching base s390 are either ACKed or written by the s390
  maintainers
- One base KVM patch "KVM: add kvm_is_error_gpa() helper"
- One patch introduces the notion of VM device attributes

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Conflicts:
	include/uapi/linux/kvm.h
2014-04-22 10:51:06 -03:00
Michael Mueller
e325fe69aa KVM: s390: Factor out handle_itdb to handle TX aborts
Factor out the new function handle_itdb(), which copies the ITDB into
guest lowcore to fully handle a TX abort.

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:54 +02:00
Michael Mueller
a86dcc2482 KVM: s390: replace TDB_ADDR by __LC_PGM_TDB
The generically assembled low core labels already contain the
address for the TDB.

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:53 +02:00
Christian Borntraeger
67335e63c9 KVM: s390: Drop pending interrupts on guest exit
On hard exits (abort, sigkill) we have have some kvm_s390_interrupt_info
structures hanging around. Delete those on exit to avoid memory leaks.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: stable@vger.kernel.org
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
2014-04-22 13:24:53 +02:00
David Hildenbrand
f71d0dc508 KVM: s390: no timer interrupts when single-stepping a guest
When a guest is single-stepped, we want to disable timer interrupts. Otherwise,
the guest will continuously execute the external interrupt handler and make
debugging of code where timer interrupts are enabled almost impossible.

The delivery of timer interrupts can be enforced in such sections by setting a
breakpoint and continuing execution.

In order to disable timer interrupts, they are disabled in the control register
of the guest just before SIE entry and are suppressed in the interrupt
check/delivery methods.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:52 +02:00
David Hildenbrand
bb78c5ec91 KVM: s390: move timer interrupt checks into own functions
This patch moves the checks for enabled timer (clock-comparator) interrupts and pending
timer interrupts into own functions, making the code better readable and easier to
maintain.

The method kvm_cpu_has_pending_timer is filled with life.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:52 +02:00
David Hildenbrand
27291e2165 KVM: s390: hardware support for guest debugging
This patch adds support to debug the guest using the PER facility on s390.
Single-stepping, hardware breakpoints and hardware watchpoints are supported. In
order to use the PER facility of the guest without it noticing it, the control
registers of the guest have to be patched and access to them has to be
intercepted(stctl, stctg, lctl, lctlg).

All PER program interrupts have to be intercepted and only the relevant PER
interrupts for the guest have to be given back. Special care has to be taken
about repeated exits on the same hardware breakpoint. The intervention of the
host in the guests PER configuration is not fully transparent. PER instruction
nullification can not be used by the guest and too many storage alteration
events may be reported to the guest (if it is activated for special address
ranges only) when the host concurrently debugging it.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:51 +02:00
David Hildenbrand
af1827e773 KVM: s390: kernel header addition for guest debugging
This patch adds the structs to the kernel headers needed to pass information
from/to userspace in order to debug a guest on s390 with hardware support.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:50 +02:00
David Hildenbrand
aba0750889 KVM: s390: emulate stctl and stctg
Introduce the methods to emulate the stctl and stctg instruction. Added tracing
code.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:50 +02:00
David Hildenbrand
8712836b30 KVM: s390: deliver program irq parameters and use correct ilc
When a program interrupt was to be delivered until now, no program interrupt
parameters were stored in the low-core of the target vcpu.

This patch enables the delivery of those program interrupt parameters, takes
care of concurrent PER events which can be injected in addition to any program
interrupt and uses the correct instruction length code (depending on the
interception code) for the injection of program interrupts.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:49 +02:00
David Hildenbrand
439716a5ca KVM: s390: extract irq parameters of intercepted program irqs
Whenever a program interrupt is intercepted, some parameters are stored in the
sie control block. These parameters have to be extracted in order to be
reinjected correctly. This patch also takes care of intercepted PER events which
can occurr in addition to any program interrupt.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:49 +02:00
Jens Freimann
da7cf2570c s390: add fields to lowcore definition
This patch adds fields which are currently missing but needed for the correct
injection of interrupts.

This is based on a patch by David Hildenbrand

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:49 +02:00
Jens Freimann
21ee7ffd17 s390: rename and split lowcore field per_perc_atmid
per_perc_atmid is currently a two-byte field that combines two
fields, the PER code and the PER Addressing-and-Translation-Mode
Identification (ATMID)

Let's make them accessible indepently and also rename per_cause to
per_code.

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:48 +02:00
Jens Freimann
3d53b46ce8 s390: fix name of lowcore field at offset 0xa3
According to the Principles of Operation, at offset 0xA3
in the lowcore we have the "Architectural-Mode identification",
not an "access identification".

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:48 +02:00
Heiko Carstens
e497a96ae8 KVM: s390: cleanup kvm_s390_real_to_abs()
Add kerneldoc comment to kvm_s390_real_to_abs() and change the code
so it matches the coding style of the rest of gaccess.h.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:47 +02:00
Heiko Carstens
3263bd1637 KVM: s390: remove old guest access functions
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:47 +02:00
Heiko Carstens
645c5bc1d5 KVM: s390: convert handle_stsi()
Convert handle_stsi() to new guest access functions.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:46 +02:00
Heiko Carstens
f987a3eef0 KVM: s390: convert handle lctl[g]()
Convert handle lctl[g]() to new guest access functions.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:46 +02:00
Heiko Carstens
7d777d7824 KVM: s390: convert handle_stidp()
Convert handle_stidp() to new guest access functions.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:45 +02:00
Heiko Carstens
2d8bcaeda1 KVM: s390: convert handle_lpsw[e]()
Convert handle_lpsw[e]() to new guest access functions.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:45 +02:00
Cornelia Huck
2f32d4ea28 KVM: s390: reinject io interrupt on tpi failure
The tpi instruction should be suppressed on addressing and protection
exceptions, so we need to re-inject the dequeued io interrupt in that
case.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:45 +02:00
Heiko Carstens
4799b557c9 KVM: s390: convert handle_tpi()
Convert handle_tpi() to new guest access functions.

The code now sets up a structure which is copied with a single call to
guest space instead of issuing several separate guest access calls.
This is necessary since the to be copied data may cross a page boundary.
If a protection exception happens while accessing any of the pages, the
instruction is suppressed and may not have modified any memory contents.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22 13:24:44 +02:00