Commit Graph

506439 Commits

Author SHA1 Message Date
Paul Burton 84ab45b338 MIPS: disable FPU if the mode is unsupported
The expected semantics of __enable_fpu are for the FPU to be enabled
in the given mode if possible, otherwise for the FPU to be left
disabled and SIGFPE returned. The FPU was incorrectly being left
enabled in cases where the desired value for FR was unavailable.
Without ensuring the FPU is disabled in this case, it would be
possible for userland to go on to execute further FP instructions
natively in the incorrect mode, rather than those instructions being
trapped & emulated as they need to be.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9167/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:47 +01:00
Paul Burton ac9ad83bc3 MIPS: prevent FP context set via ptrace being discarded
If a ptracee has not used the FPU and the ptracer sets its FP context
using PTRACE_POKEUSR, PTRACE_SETFPREGS or PTRACE_SETREGSET then that
context will be discarded upon either the ptracee using the FPU or a
further write to the context via ptrace. Prevent this loss by recording
that the task has "used" math once its FP context has been written to.
The context initialisation code that was present for the PTRACE_POKEUSR
case is reused for the other 2 cases to provide consistent behaviour
for the different ptrace requests.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9166/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:47 +01:00
Paul Burton ad70c13a93 MIPS: Ensure FCSR cause bits are clear after invoking FPU emulator
When running the emulator to handle an instruction that raised an FP
unimplemented operation exception, the FCSR cause bits were being
cleared. This is done to ensure that the kernel does not take an FP
exception when later restoring FP context to registers. However, this
was not being done when the emulator is invoked in response to a
coprocessor unusable exception. This happens in 2 cases:

  - There is no FPU present in the system. In this case things were
    OK, since the FP context is never restored to hardware registers
    and thus no FP exception may be raised when restoring FCSR.

  - The FPU could not be configured to the mode required by the task.
    In this case it would be possible for the emulator to set cause
    bits which are later restored to hardware if the task migrates
    to a CPU whose associated FPU does support its mode requirements,
    or if the tasks FP mode requirements change.

Consistently clear the cause bits after invoking the emulator, by moving
the clearing to process_fpemu_return and ensuring this is always called
before the tasks FP context is restored. This will make it easier to
catch further paths invoking the emulator in future, as will be
introduced in further patches.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9165/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:46 +01:00
Paul Burton 091be550a7 MIPS: clear MSACSR cause bits when handling MSA FP exception
Much like for traditional scalar FP exceptions, the cause bits in the
MSACSR register need to be cleared following an MSA FP exception.
Without doing so the exception will simply be raised again whenever
the kernel restores MSACSR from a tasks saved context, leading to
undesirable spurious exceptions. Clear the cause bits from the
handle_msa_fpe function, mirroring the way handle_fpe clears the
cause bits in FCSR.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9164/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:45 +01:00
Paul Burton e1bebbab1e MIPS: wrap cfcmsa & ctcmsa accesses for toolchains with MSA support
Uses of the cfcmsa & ctcmsa instructions were not being wrapped by a
macro in the case where the toolchain supports MSA, since the arguments
exactly match a typical use of the instructions. However using current
toolchains this leads to errors such as:

  arch/mips/kernel/genex.S:437: Error: opcode not supported on this processor: mips32r2 (mips32r2) `cfcmsa $5,1'

Thus uses of the instructions must be in the context of a ".set msa"
directive, however doing that from the users of the instructions would
be messy due to the possibility that the toolchain does not support
MSA. Fix this by renaming the macros (prepending an underscore) in order
to avoid recursion when attempting to emit the instructions, and provide
implementations for the TOOLCHAIN_SUPPORTS_MSA case which ".set msa" as
appropriate.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9163/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:44 +01:00
Paul Burton a3a49810c5 MIPS: remove MSA macro recursion
Recursive macros made the code more concise & worked great for the
case where the toolchain doesn't support MSA. However, with toolchains
which do support MSA they lead to build failures such as:

  arch/mips/kernel/r4k_switch.S: Assembler messages:
  arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w(0+1)[2],$1'
  arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w(0+1)[3],$1'
  arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w((0+1)+1)[2],$1'
  arch/mips/kernel/r4k_switch.S:148: Error: invalid operands `insert.w $w((0+1)+1)[3],$1'
  ...

Drop the recursion from msa_init_all_upper invoking the msa_init_upper
macro explicitly for each vector register.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9162/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:44 +01:00
Paul Burton f23ce3883a MIPS: assume at as source/dest of MSA copy/insert instructions
Assuming at ($1) as the source or destination register of copy or
insert instructions:

  - Simplifies the macros providing those instructions for toolchains
    without MSA support.

  - Avoids an unnecessary move instruction when at is used as the source
    or destination register anyway.

  - Is sufficient for the uses to be introduced in the kernel by a
    subsequent patch.

Note that due to a patch ordering snafu on my part this also fixes the
currently broken build with MSA support enabled. The build has been
broken since commit c9017757c5 "MIPS: init upper 64b of vector
registers when MSA is first used", which this patch should have
preceeded.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9161/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:43 +01:00
Paul Burton 631afc65e8 MIPS: Push .set mips64r* into the functions needing it
The {save,restore}_fp_context{,32} functions require that the assembler
allows the use of sdc instructions on any FP register, and this is
acomplished by setting the arch to mips64r2 or mips64r6
(using MIPS_ISA_ARCH_LEVEL_RAW).

However this has the effect of enabling the assembler to use mips64
instructions in the expansion of pseudo-instructions. This was done in
the (now-reverted) commit eec43a224c "MIPS: Save/restore MSA context
around signals" which led to my mistakenly believing that there was an
assembler bug, when in reality the assembler was just emitting mips64
instructions. Avoid the issue for future commits which will add code to
r4k_fpu.S by pushing the .set MIPS_ISA_ARCH_LEVEL_RAW directives into
the functions that require it, and remove the spurious assertion
declaring the assembler bug.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
[james.hogan@imgtec.com: Rebase on v4.0-rc1 and reword commit message to
 reflect use of MIPS_ISA_ARCH_LEVEL_RAW]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9612/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:42:42 +01:00
James Hogan acaf6a97d6 MIPS: lose_fpu(): Disable FPU when MSA enabled
The lose_fpu() function only disables the FPU in CP0_Status.CU1 if the
FPU is in use and MSA isn't enabled.

This isn't necessarily a problem because KSTK_STATUS(current), the
version of CP0_Status stored on the kernel stack on entry from user
mode, does always get updated and gets restored when returning to user
mode, but I don't think it was intended, and it is inconsistent with the
case of only the FPU being in use. Sometimes leaving the FPU enabled may
also mask kernel bugs where FPU operations are executed when the FPU
might not be enabled.

So lets disable the FPU in the MSA case too.

Fixes: 33c771ba5c ("MIPS: save/disable MSA in lose_fpu")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9323/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-27 19:39:42 +01:00
Jan Kiszka b3a2a9076d KVM: nVMX: Add support for rdtscp
If the guest CPU is supposed to support rdtscp and the host has rdtscp
enabled in the secondary execution controls, we can also expose this
feature to L1. Just extend nested_vmx_exit_handled to properly route
EXIT_REASON_RDTSCP.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-26 22:33:48 -03:00
Andre Przywara a9cf86f62b KVM: arm/arm64: prepare GICv2 emulation to be handled by kvm_io_bus
Using the framework provided by the recent vgic.c changes we register
a kvm_io_bus device when initializing the virtual GICv2.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:15 +00:00
Andre Przywara 6777f77f0f KVM: arm/arm64: implement kvm_io_bus MMIO handling for the VGIC
Currently we use a lot of VGIC specific code to do the MMIO
dispatching.
Use the previous reworks to add kvm_io_bus style MMIO handlers.

Those are not yet called by the MMIO abort handler, also the actual
VGIC emulator function do not make use of it yet, but will be enabled
with the following patches.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:14 +00:00
Andre Przywara 9f199d0a0e KVM: arm/arm64: simplify vgic_find_range() and callers
The vgic_find_range() function in vgic.c takes a struct kvm_exit_mmio
argument, but actually only used the length field in there. Since we
need to get rid of that structure in that part of the code anyway,
let's rework the function (and it's callers) to pass the length
argument to the function directly.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:14 +00:00
Andre Przywara cf50a1eb43 KVM: arm/arm64: rename struct kvm_mmio_range to vgic_io_range
The name "kvm_mmio_range" is a bit bold, given that it only covers
the VGIC's MMIO ranges. To avoid confusion with kvm_io_range, rename
it to vgic_io_range.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:14 +00:00
Andre Przywara f0e4b2776c KVM: x86: remove now unneeded include directory from Makefile
virt/kvm was never really a good include directory for anything else
than locally included headers.
With the move of iodev.h there is no need anymore to add this
directory the compiler's include path, so remove it from the x86 kvm
Makefile.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:13 +00:00
Andre Przywara 5d9d15af1c KVM: arm/arm64: remove now unneeded include directory from Makefile
virt/kvm was never really a good include directory for anything else
than locally included headers.
With the move of iodev.h there is no need anymore to add this
directory the compiler's include path, so remove it from the arm and
arm64 kvm Makefile.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:13 +00:00
Andre Przywara af669ac6dc KVM: move iodev.h from virt/kvm/ to include/kvm
iodev.h contains definitions for the kvm_io_bus framework. This is
needed both by the generic KVM code in virt/kvm as well as by
architecture specific code under arch/. Putting the header file in
virt/kvm and using local includes in the architecture part seems at
least dodgy to me, so let's move the file into include/kvm, so that a
more natural "#include <kvm/iodev.h>" can be used by all of the code.
This also solves a problem later when using struct kvm_io_device
in arm_vgic.h.
Fixing up the FSF address in the GPL header and a wrong include path
on the way.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:12 +00:00
Nikolay Nikolaev e32edf4fd0 KVM: Redesign kvm_io_bus_ API to pass VCPU structure to the callbacks.
This is needed in e.g. ARM vGIC emulation, where the MMIO handling
depends on the VCPU that does the access.

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:11 +00:00
Radim Krčmář a123374ff3 KVM: x86: inline kvm_ioapic_handles_vector()
An overhead from function call is not appropriate for its size and
frequency of execution.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-23 21:20:52 -03:00
Marcelo Tosatti bbf4aef89d KVM: s390: Features and fixes for 4.1 (kvm/next)
1. Fixes
 2. Implement access register mode in KVM
 3. Provide a userspace post handler for the STSI instruction
 4. Provide an interface for compliant memory accesses
 5. Provide an interface for getting/setting the guest storage key
 6. Fixup for the vector facility patches: do not announce the
    vector facility in the guest for old QEMUs.
 
 1-5 were initially shown as RFC in
 
 http://www.spinics.net/lists/kvm/msg114720.html
 
 some small review changes
 - added some ACKs
 - have the AR mode patches first
 - get rid of unnecessary AR_INVAL define
 - typos and language
 
 6. two new patches
 The two new patches fixup the vector support patches that were
 introduced in the last pull request for QEMU versions that dont
 know about vector support and guests that do. (We announce the
 facility bit, but dont enable the facility so vector aware guests
 will crash on vector instructions).
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Merge tag 'kvm-s390-next-20150318' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into queue

KVM: s390: Features and fixes for 4.1 (kvm/next)

1. Fixes
2. Implement access register mode in KVM
3. Provide a userspace post handler for the STSI instruction
4. Provide an interface for compliant memory accesses
5. Provide an interface for getting/setting the guest storage key
6. Fixup for the vector facility patches: do not announce the
   vector facility in the guest for old QEMUs.

1-5 were initially shown as RFC in

http://www.spinics.net/lists/kvm/msg114720.html

some small review changes
- added some ACKs
- have the AR mode patches first
- get rid of unnecessary AR_INVAL define
- typos and language

6. two new patches
The two new patches fixup the vector support patches that were
introduced in the last pull request for QEMU versions that dont
know about vector support and guests that do. (We announce the
facility bit, but dont enable the facility so vector aware guests
will crash on vector instructions).
2015-03-23 20:32:02 -03:00
Marcelo Tosatti 0a4e6be9ca x86: kvm: Revert "remove sched notifier for cross-cpu migrations"
The following point:

    2. per-CPU pvclock time info is updated if the
       underlying CPU changes.

Is not true anymore since "KVM: x86: update pvclock area conditionally,
on cpu migration".

Add task migration notification back.

Problem noticed by Andy Lutomirski.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
CC: stable@kernel.org # 3.11+
2015-03-23 20:22:48 -03:00
Takuya Yoshikawa 58d2930f4e KVM: Eliminate extra function calls in kvm_get_dirty_log_protect()
When all bits in mask are not set,
kvm_arch_mmu_enable_log_dirty_pt_masked() has nothing to do.  But since
it needs to be called from the generic code, it cannot be inlined, and
a few function calls, two when PML is enabled, are wasted.

Since it is common to see many pages remain clean, e.g. framebuffers can
stay calm for a long time, it is worth eliminating this overhead.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-18 22:23:33 -03:00
Bandan Das faac245851 KVM: SVM: Fix confusing message if no exit handlers are installed
I hit this path on a AMD box and thought
someone was playing a April Fool's joke on me.

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-18 21:52:49 -03:00
Xiubo Li 52eb5a6d57 KVM: x86: For the symbols used locally only should be static type
This patch fix the following sparse warnings:

for arch/x86/kvm/x86.c:
warning: symbol 'emulator_read_write' was not declared. Should it be static?
warning: symbol 'emulator_write_emulated' was not declared. Should it be static?
warning: symbol 'emulator_get_dr' was not declared. Should it be static?
warning: symbol 'emulator_set_dr' was not declared. Should it be static?

for arch/x86/kvm/pmu.c:
warning: symbol 'fixed_pmc_events' was not declared. Should it be static?

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-17 22:38:28 -03:00
Xiubo Li 795a149e78 KVM: x86: Avoid using plain integer as NULL pointer warning
This patch fix the following sparse warning:

for file arch/x86/kvm/x86.c:
warning: Using plain integer as NULL pointer

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-17 22:34:25 -03:00
Michael Mueller 18280d8b4b KVM: s390: represent SIMD cap in kvm facility
The patch represents capability KVM_CAP_S390_VECTOR_REGISTERS by means
of the SIMD facility bit. This allows to a) disable the use of SIMD when
used in conjunction with a not-SIMD-aware QEMU, b) to enable SIMD when
used with a SIMD-aware version of QEMU and c) finally by means of a QEMU
version using the future cpu model ioctls.

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com>
Tested-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:33:14 +01:00
Michael Mueller 400ac6cd73 KVM: s390: drop SIMD bit from kvm_s390_fac_list_mask
Setting the SIMD bit in the KVM mask is an issue because it makes the
facility visible but not usable to the guest, thus it needs to be
removed again.

Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:33:11 +01:00
Jason J. Herne 30ee2a984f KVM: s390: Create ioctl for Getting/Setting guest storage keys
Provide the KVM_S390_GET_SKEYS and KVM_S390_SET_SKEYS ioctl which can be used
to get/set guest storage keys. This functionality is needed for live migration
of s390 guests that use storage keys.

Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:33:06 +01:00
Ekaterina Tumanova e44fc8c9da KVM: s390: introduce post handlers for STSI
The Store System Information (STSI) instruction currently collects all
information it relays to the caller in the kernel. Some information,
however, is only available in user space. An example of this is the
guest name: The kernel always sets "KVMGuest", but user space knows the
actual guest name.

This patch introduces a new exit, KVM_EXIT_S390_STSI, guarded by a
capability that can be enabled by user space if it wants to be able to
insert such data. User space will be provided with the target buffer
and the requested STSI function code.

Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:26:51 +01:00
Thomas Huth 41408c28f2 KVM: s390: Add MEMOP ioctls for reading/writing guest memory
On s390, we've got to make sure to hold the IPTE lock while accessing
logical memory. So let's add an ioctl for reading and writing logical
memory to provide this feature for userspace, too.
The maximum transfer size of this call is limited to 64kB to prevent
that the guest can trigger huge copy_from/to_user transfers. QEMU
currently only requests up to one or two pages so far, so 16*4kB seems
to be a reasonable limit here.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:26:24 +01:00
Alexander Yarygin 664b497353 KVM: s390: Add access register mode
Access register mode is one of the modes that control dynamic address
translation. In this mode the address space is specified by values of
the access registers. The effective address-space-control element is
obtained from the result of the access register translation. See
the "Access-Register Introduction" section of the chapter 5 "Program
Execution" in "Principles of Operations" for more details.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:25:57 +01:00
Alexander Yarygin 75a1812230 KVM: s390: Optimize paths where get_vcpu_asce() is invoked
During dynamic address translation the get_vcpu_asce()
function can be invoked several times. It's ok for usual modes, but will
be slow if CPUs are in AR mode. Let's call the get_vcpu_asce() once and
pass the result to the called functions.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:25:31 +01:00
Alexander Yarygin 8ae04b8f50 KVM: s390: Guest's memory access functions get access registers
In access register mode, the write_guest() read_guest() and other
functions will invoke the access register translation, which
requires an ar, designated by one of the instruction fields.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:25:04 +01:00
Alexander Yarygin dd9e5b7bdb KVM: s390: Fix low-address protection for real addresses
The kvm_s390_check_low_addr_protection() function is used only with real
addresses. According to the POP (the "Low-Address Protection"
paragraph in chapter 3), if the effective address is real or absolute,
the low-address protection procedure should raise a PROTECTION exception
only when the low-address protection is enabled in the control register
0 and the address is low.
This patch removes ASCE checks from the function and renames it to
better reflect its behavior.

Cc: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:24:38 +01:00
Dominik Dingel 40f5b735e8 KVM: s390: cleanup jump lables in kvm_arch_init_vm
As all cleanup functions can handle their respective NULL case
there is no need to have more than one error jump label.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:24:11 +01:00
Geert Uytterhoeven 1e8d242478 KVM: s390: Spelling s/intance/instance/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Message-Id: <1425932832-6244-1-git-send-email-geert+renesas@glider.be>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-03-17 16:22:56 +01:00
Christoffer Dall 1a74847885 arm/arm64: KVM: Fix migration race in the arch timer
When a VCPU is no longer running, we currently check to see if it has a
timer scheduled in the future, and if it does, we schedule a host
hrtimer to notify is in case the timer expires while the VCPU is still
not running.  When the hrtimer fires, we mask the guest's timer and
inject the timer IRQ (still relying on the guest unmasking the time when
it receives the IRQ).

This is all good and fine, but when migration a VM (checkpoint/restore)
this introduces a race.  It is unlikely, but possible, for the following
sequence of events to happen:

 1. Userspace stops the VM
 2. Hrtimer for VCPU is scheduled
 3. Userspace checkpoints the VGIC state (no pending timer interrupts)
 4. The hrtimer fires, schedules work in a workqueue
 5. Workqueue function runs, masks the timer and injects timer interrupt
 6. Userspace checkpoints the timer state (timer masked)

At restore time, you end up with a masked timer without any timer
interrupts and your guest halts never receiving timer interrupts.

Fix this by only kicking the VCPU in the workqueue function, and sample
the expired state of the timer when entering the guest again and inject
the interrupt and mask the timer only then.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-14 13:48:00 +01:00
Christoffer Dall 47a98b15ba arm/arm64: KVM: support for un-queuing active IRQs
Migrating active interrupts causes the active state to be lost
completely. This implements some additional bitmaps to track the active
state on the distributor and export this to user space.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-14 13:46:44 +01:00
Alex Bennée 71760950bf arm/arm64: KVM: add a common vgic_queue_irq_to_lr fn
This helps re-factor away some of the repetitive code and makes the code
flow more nicely.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-14 13:44:52 +01:00
Alex Bennée ecccf0cc72 arm/arm64: KVM: export VCPU power state via MP_STATE ioctl
To cleanly restore an SMP VM we need to ensure that the current pause
state of each vcpu is correctly recorded. Things could get confused if
the CPU starts running after migration restore completes when it was
paused before it state was captured.

We use the existing KVM_GET/SET_MP_STATE ioctl to do this. The arm/arm64
interface is a lot simpler as the only valid states are
KVM_MP_STATE_RUNNABLE and KVM_MP_STATE_STOPPED.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-14 13:44:52 +01:00
Christoffer Dall ae705930fc arm/arm64: KVM: Keep elrsr/aisr in sync with software model
There is an interesting bug in the vgic code, which manifests itself
when the KVM run loop has a signal pending or needs a vmid generation
rollover after having disabled interrupts but before actually switching
to the guest.

In this case, we flush the vgic as usual, but we sync back the vgic
state and exit to userspace before entering the guest.  The consequence
is that we will be syncing the list registers back to the software model
using the GICH_ELRSR and GICH_EISR from the last execution of the guest,
potentially overwriting a list register containing an interrupt.

This showed up during migration testing where we would capture a state
where the VM has masked the arch timer but there were no interrupts,
resulting in a hung test.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Reported-by: Alex Bennee <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-14 13:42:07 +01:00
Jan Kiszka ae1f576707 KVM: nVMX: Do not emulate #UD while in guest mode
While in L2, leave all #UD to L2 and do not try to emulate it. If L1 is
interested in doing this, it reports its interest via the exception
bitmap, and we never get into handle_exception of L0 anyway.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-13 13:44:43 -03:00
Jan Kiszka b34a80517b KVM: x86: Fix re-execution of patched vmmcall
For a very long time (since 2b3d2a20), the path handling a vmmcall
instruction of the guest on an Intel host only applied the patch but no
longer handled the hypercall. The reverse case, vmcall on AMD hosts, is
fine. As both em_vmcall and em_vmmcall actually have to do the same, we
can fix the issue by consolidating both into the same handler.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-13 13:27:54 -03:00
David Kaplan 5e57518d99 x86: svm: use cr_interception for SVM_EXIT_CR0_SEL_WRITE
Another patch in my war on emulate_on_interception() use as a svm exit handler.

These were pulled out of a larger patch at the suggestion of Radim Krcmar, see
https://lkml.org/lkml/2015/2/25/559

Changes since v1:
	* fixed typo introduced after test, retested

Signed-off-by: David Kaplan <david.kaplan@amd.com>
[separated out just cr_interception part from larger removal of
INTERCEPT_CR0_WRITE, forward ported, tested]
Signed-off-by: Joel Schopp <joel.schopp@amd.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-13 11:46:41 -03:00
Wei Yongjun b52104e509 arm/arm64: KVM: fix missing unlock on error in kvm_vgic_create()
Add the missing unlock before return from function kvm_vgic_create()
in the error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-13 11:40:57 +01:00
Marcelo Tosatti 2b25385761 KVM: s390: Features and Fixes for 4.1 (kvm/next)
1. Several Fixes and enhancements
 ---------------------------------
 - These 3 patches have cc stable:
 b75f4c9 KVM: s390: Zero out current VMDB of STSI before including level3 data.
 261520d KVM: s390: fix handling of write errors in the tpi handler
 15462e3 KVM: s390: reinjection of irqs can fail in the tpi handler
 
 2. SIMD support the kernel part (introduced with z13)
 -----------------------------------------------------
 - two KVM-generic changes in kvm.h:
 1. New capability that can be enabled: KVM_CAP_S390_VECTOR_REGISTERS
 2. increased padding size for sync regs in struct kvm_run to clarify that
    sync regs can be larger than 1k. This is fine as this is the last
    element in the structure.
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Merge tag 'kvm-s390-next-20150306' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into queue

KVM: s390: Features and Fixes for 4.1 (kvm/next)

1. Several Fixes and enhancements
---------------------------------
- These 3 patches have cc stable:
b75f4c9 KVM: s390: Zero out current VMDB of STSI before including level3 data.
261520d KVM: s390: fix handling of write errors in the tpi handler
15462e3 KVM: s390: reinjection of irqs can fail in the tpi handler

2. SIMD support the kernel part (introduced with z13)
-----------------------------------------------------
- two KVM-generic changes in kvm.h:
1. New capability that can be enabled: KVM_CAP_S390_VECTOR_REGISTERS
2. increased padding size for sync regs in struct kvm_run to clarify that
   sync regs can be larger than 1k. This is fine as this is the last
   element in the structure.
2015-03-12 22:09:35 -03:00
Christian Borntraeger 1662e862a8 KVM: MAINTAINERS: add file arch/x86/kernel/kvm.c|kvmclock.c
The KVM list should be CCed on changes for arch/x86/kernel/kvm.c
and arch/x86/kernel/kvmclock.c

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-12 21:57:58 -03:00
Marc Zyngier aeda9130c3 arm/arm64: KVM: Optimize handling of Access Flag faults
Now that we have page aging in Stage-2, it becomes obvious that
we're doing way too much work handling the fault.

The page is not going anywhere (it is still mapped), the page
tables are already allocated, and all we want is to flip a bit
in the PMD or PTE. Also, we can avoid any form of TLB invalidation,
since a page with the AF bit off is not allowed to be cached.

An obvious solution is to have a separate handler for FSC_ACCESS,
where we pride ourselves to only do the very minimum amount of
work.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-12 22:34:49 +01:00
Marc Zyngier 35307b9a5f arm/arm64: KVM: Implement Stage-2 page aging
Until now, KVM/arm didn't care much for page aging (who was swapping
anyway?), and simply provided empty hooks to the core KVM code. With
server-type systems now being available, things are quite different.

This patch implements very simple support for page aging, by clearing
the Access flag in the Stage-2 page tables. On access fault, the current
fault handling will write the PTE or PMD again, putting the Access flag
back on.

It should be possible to implement a much faster handling for Access
faults, but that's left for a later patch.

With this in place, performance in VMs is degraded much more gracefully.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-12 22:34:43 +01:00
Marc Zyngier 1d2ebaccc7 arm/arm64: KVM: Allow handle_hva_to_gpa to return a value
So far, handle_hva_to_gpa was never required to return a value.
As we prepare to age pages at Stage-2, we need to be able to
return a value from the iterator (kvm_test_age_hva).

Adapt the code to handle this situation. No semantic change.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-12 22:34:30 +01:00