319 Commits

Author SHA1 Message Date
Paolo Bonzini
3bda03865f KVM: s390: Fix for 5.7 and maintainer update
- Silence false positive lockdep warning
 - add Claudio as reviewer
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABAgAGBQJenY6AAAoJEBF7vIC1phx8bykQAK+QZyD+H/zGNuqeUVn0sh8e
 yKUVMR+kuE+l57q77nt2AYVxqpCD9xSKRR+SOSLzhVH/HJf625nm+Ny/WOWMebwJ
 EA/KK+v15T5rga8gFza+4cPg4v/pHwjHhSbjTb1JWg+8cJR1BTj6OxRuTtWr5+25
 GF4RhkJOit/VhNbCo1aIgs7/7F1pPALstdPAUsHYe1PeULdRMVqSVluXT2KTPhpi
 /kzDw8sKKcYgv/eaVdcNoHv+VX1AWIRDAKEttCywyocfbu0ESwadmR7C0qlm1446
 HqowP6F0xCF0Whi/65aN4ZOv7wjO/qrV08DZ7JLA3/oKlXtZ1ieyiE2q/P1frSo1
 gvmuHiH5/UI6t6a/BSCpJwqcilxKYArqAAYBKoGiJhTbsJStqw0wl41klWTKXlTq
 VrCvjoUxQ9JMjFCQ1GXOU+ODNyX2IwZYptJ5vF24HYzBJwUBe3HPG9/BA8YcodzG
 qGQ5IKv0Q1IFTwOqnt557H0MjcBtNIEx54aLJrPy3wldsiNSj39Ft0cuvnbR+Q4F
 QhKk88dHtd7NW1IirfgYmLGe0rB1ANKM7wUGEdM5w2y5Eg8wCs8/P4KeGh0YyFI9
 xPqZDfwof6KkDjOGFXr/CeD/thi+km0/FpePb7cL5Ow4a+JmrCvqQiXrf0TbnFpv
 t5ZlHnGzoSHsEaRgmJ+X
 =d46L
 -----END PGP SIGNATURE-----

Merge tag 'kvm-s390-master-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master

KVM: s390: Fix for 5.7 and maintainer update

- Silence false positive lockdep warning
- add Claudio as reviewer
2020-04-21 09:37:13 -04:00
Uros Bizjak
fb56baae5e KVM: VMX: Enable machine check support for 32bit targets
There is no reason to limit the use of do_machine_check
to 64bit targets. MCE handling works for both target familes.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: stable@vger.kernel.org
Fixes: a0861c02a981 ("KVM: Add VT-x machine check support")
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Message-Id: <20200414071414.45636-1-ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-14 04:22:10 -04:00
Xiaoyao Li
e6f8b6c12f KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest
Two types of #AC can be generated in Intel CPUs:
 1. legacy alignment check #AC
 2. split lock #AC

Reflect #AC back into the guest if the guest has legacy alignment checks
enabled or if split lock detection is disabled.

If the #AC is not a legacy one and split lock detection is enabled, then
invoke handle_guest_split_lock() which will either warn and disable split
lock detection for this task or force SIGBUS on it.

[ tglx: Switch it to handle_guest_split_lock() and rename the misnamed
  helper function. ]

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.176308876@linutronix.de
2020-04-11 16:42:41 +02:00
Vitaly Kuznetsov
dbef2808af KVM: VMX: fix crash cleanup when KVM wasn't used
If KVM wasn't used at all before we crash the cleanup procedure fails with
 BUG: unable to handle page fault for address: ffffffffffffffc8
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 23215067 P4D 23215067 PUD 23217067 PMD 0
 Oops: 0000 [#8] SMP PTI
 CPU: 0 PID: 3542 Comm: bash Kdump: loaded Tainted: G      D           5.6.0-rc2+ #823
 RIP: 0010:crash_vmclear_local_loaded_vmcss.cold+0x19/0x51 [kvm_intel]

The root cause is that loaded_vmcss_on_cpu list is not yet initialized,
we initialize it in hardware_enable() but this only happens when we start
a VM.

Previously, we used to have a bitmap with enabled CPUs and that was
preventing [masking] the issue.

Initialized loaded_vmcss_on_cpu list earlier, right before we assign
crash_vmclear_loaded_vmcss pointer. blocked_vcpu_on_cpu list and
blocked_vcpu_on_cpu_lock are moved altogether for consistency.

Fixes: 31603d4fc2bb ("KVM: VMX: Always VMCLEAR in-use VMCSes during crash with kexec support")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200401081348.1345307-1-vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-07 08:35:36 -04:00
Linus Torvalds
8c1b724ddb ARM:
* GICv4.1 support
 * 32bit host removal
 
 PPC:
 * secure (encrypted) using under the Protected Execution Framework
 ultravisor
 
 s390:
 * allow disabling GISA (hardware interrupt injection) and protected
 VMs/ultravisor support.
 
 x86:
 * New dirty bitmap flag that sets all bits in the bitmap when dirty
 page logging is enabled; this is faster because it doesn't require bulk
 modification of the page tables.
 * Initial work on making nested SVM event injection more similar to VMX,
 and less buggy.
 * Various cleanups to MMU code (though the big ones and related
 optimizations were delayed to 5.8).  Instead of using cr3 in function
 names which occasionally means eptp, KVM too has standardized on "pgd".
 * A large refactoring of CPUID features, which now use an array that
 parallels the core x86_features.
 * Some removal of pointer chasing from kvm_x86_ops, which will also be
 switched to static calls as soon as they are available.
 * New Tigerlake CPUID features.
 * More bugfixes, optimizations and cleanups.
 
 Generic:
 * selftests: cleanups, new MMU notifier stress test, steal-time test
 * CSV output for kvm_stat.
 
 KVM/MIPS has been broken since 5.5, it does not compile due to a patch committed
 by MIPS maintainers.  I had already prepared a fix, but the MIPS maintainers
 prefer to fix it in generic code rather than KVM so they are taking care of it.
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAl6GOnIUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroMfxwf/ZKLZiRoaovXCOG71M/eHtQb8ZIqU
 3MPy+On3eC5Sk/aBxWUL9EFZsbYG6kYdbZ1VOvG9XPBoLlnkDSm/IR0kaELHtnjj
 oGVda/tvGn46Ne39y8xBptmb91WDcWH0vFthT/CwlMxAw3xjr+gG7Qyo+8F2CW6m
 SSSuLiHSBnyO1cQKruBTHZ8qnR8LlnfXEqtd6Y4LFLic0LbLIoIdRcT3wjQrcZrm
 Djd7wbTEYZjUfoqZ72ekwEDUsONcDLDSKcguDO9pSMSCGhpxCVT5Vy68KRpoIMs2
 nzNWDKjvqQo5zb2+GWxJgkd12Hv+n7PCXZMbVrWBu1pQsewUns9m4mkpGw==
 =6fGt
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - GICv4.1 support

   - 32bit host removal

  PPC:
   - secure (encrypted) using under the Protected Execution Framework
     ultravisor

  s390:
   - allow disabling GISA (hardware interrupt injection) and protected
     VMs/ultravisor support.

  x86:
   - New dirty bitmap flag that sets all bits in the bitmap when dirty
     page logging is enabled; this is faster because it doesn't require
     bulk modification of the page tables.

   - Initial work on making nested SVM event injection more similar to
     VMX, and less buggy.

   - Various cleanups to MMU code (though the big ones and related
     optimizations were delayed to 5.8). Instead of using cr3 in
     function names which occasionally means eptp, KVM too has
     standardized on "pgd".

   - A large refactoring of CPUID features, which now use an array that
     parallels the core x86_features.

   - Some removal of pointer chasing from kvm_x86_ops, which will also
     be switched to static calls as soon as they are available.

   - New Tigerlake CPUID features.

   - More bugfixes, optimizations and cleanups.

  Generic:
   - selftests: cleanups, new MMU notifier stress test, steal-time test

   - CSV output for kvm_stat"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (277 commits)
  x86/kvm: fix a missing-prototypes "vmread_error"
  KVM: x86: Fix BUILD_BUG() in __cpuid_entry_get_reg() w/ CONFIG_UBSAN=y
  KVM: VMX: Add a trampoline to fix VMREAD error handling
  KVM: SVM: Annotate svm_x86_ops as __initdata
  KVM: VMX: Annotate vmx_x86_ops as __initdata
  KVM: x86: Drop __exit from kvm_x86_ops' hardware_unsetup()
  KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection
  KVM: x86: Set kvm_x86_ops only after ->hardware_setup() completes
  KVM: VMX: Configure runtime hooks using vmx_x86_ops
  KVM: VMX: Move hardware_setup() definition below vmx_x86_ops
  KVM: x86: Move init-only kvm_x86_ops to separate struct
  KVM: Pass kvm_init()'s opaque param to additional arch funcs
  s390/gmap: return proper error code on ksm unsharing
  KVM: selftests: Fix cosmetic copy-paste error in vm_mem_region_move()
  KVM: Fix out of range accesses to memslots
  KVM: X86: Micro-optimize IPI fastpath delay
  KVM: X86: Delay read msr data iff writes ICR MSR
  KVM: PPC: Book3S HV: Add a capability for enabling secure guests
  KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs
  KVM: arm64: GICv4.1: Allow non-trapping WFI when using HW SGIs
  ...
2020-04-02 15:13:15 -07:00
Linus Torvalds
fdf5563a72 Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Ingo Molnar:
 "This topic tree contains more commits than usual:

   - most of it are uaccess cleanups/reorganization by Al

   - there's a bunch of prototype declaration (--Wmissing-prototypes)
     cleanups

   - misc other cleanups all around the map"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/mm/set_memory: Fix -Wmissing-prototypes warnings
  x86/efi: Add a prototype for efi_arch_mem_reserve()
  x86/mm: Mark setup_emu2phys_nid() static
  x86/jump_label: Move 'inline' keyword placement
  x86/platform/uv: Add a missing prototype for uv_bau_message_interrupt()
  kill uaccess_try()
  x86: unsafe_put-style macro for sigmask
  x86: x32_setup_rt_frame(): consolidate uaccess areas
  x86: __setup_rt_frame(): consolidate uaccess areas
  x86: __setup_frame(): consolidate uaccess areas
  x86: setup_sigcontext(): list user_access_{begin,end}() into callers
  x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit)
  x86: ia32_setup_rt_frame(): consolidate uaccess areas
  x86: ia32_setup_frame(): consolidate uaccess areas
  x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers
  x86/alternatives: Mark text_poke_loc_init() static
  x86/cpu: Fix a -Wmissing-prototypes warning for init_ia32_feat_ctl()
  x86/mm: Drop pud_mknotpresent()
  x86: Replace setup_irq() by request_irq()
  x86/configs: Slightly reduce defconfigs
  ...
2020-03-31 11:04:05 -07:00
Sean Christopherson
e286ac0e38 KVM: VMX: Annotate vmx_x86_ops as __initdata
Tag vmx_x86_ops with __initdata now the the struct is copied by value to
a common x86 instance of kvm_x86_ops as part of kvm_init().

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321202603.19355-9-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31 10:48:10 -04:00
Sean Christopherson
6e4fd06f3e KVM: x86: Drop __exit from kvm_x86_ops' hardware_unsetup()
Remove the __exit annotation from VMX hardware_unsetup(), the hook
can be reached during kvm_init() by way of kvm_arch_hardware_unsetup()
if failure occurs at various points during initialization.

Removing the annotation also lets us annotate vmx_x86_ops and svm_x86_ops
with __initdata; otherwise, objtool complains because it doesn't
understand that the vendor specific __initdata is being copied by value
to a non-__initdata instance.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321202603.19355-8-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31 10:48:09 -04:00
Sean Christopherson
afaf0b2f9b KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection
Replace the kvm_x86_ops pointer in common x86 with an instance of the
struct to save one pointer dereference when invoking functions.  Copy the
struct by value to set the ops during kvm_init().

Arbitrarily use kvm_x86_ops.hardware_enable to track whether or not the
ops have been initialized, i.e. a vendor KVM module has been loaded.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321202603.19355-7-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31 10:48:08 -04:00
Sean Christopherson
72b0eaa946 KVM: VMX: Configure runtime hooks using vmx_x86_ops
Configure VMX's runtime hooks by modifying vmx_x86_ops directly instead
of using the global kvm_x86_ops.  This sets the stage for waiting until
after ->hardware_setup() to set kvm_x86_ops with the vendor's
implementation.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321202603.19355-5-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31 10:48:06 -04:00
Sean Christopherson
484014faf8 KVM: VMX: Move hardware_setup() definition below vmx_x86_ops
Move VMX's hardware_setup() below its vmx_x86_ops definition so that a
future patch can refactor hardware_setup() to modify vmx_x86_ops
directly instead of indirectly modifying the ops via the global
kvm_x86_ops.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321202603.19355-4-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31 10:48:05 -04:00
Sean Christopherson
d008dfdb0e KVM: x86: Move init-only kvm_x86_ops to separate struct
Move the kvm_x86_ops functions that are used only within the scope of
kvm_init() into a separate struct, kvm_x86_init_ops.  In addition to
identifying the init-only functions without restorting to code comments,
this also sets the stage for waiting until after ->hardware_setup() to
set kvm_x86_ops.  Setting kvm_x86_ops after ->hardware_setup() is
desirable as many of the hooks are not usable until ->hardware_setup()
completes.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321202603.19355-3-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-31 10:48:04 -04:00
Paolo Bonzini
cf39d37539 KVM/arm updates for Linux 5.7
- GICv4.1 support
 - 32bit host removal
 -----BEGIN PGP SIGNATURE-----
 
 iQJDBAABCgAtFiEEn9UcU+C1Yxj9lZw9I9DQutE9ekMFAl6DKKIPHG1hekBrZXJu
 ZWwub3JnAAoJECPQ0LrRPXpDDe0P/30Oda6HJdcUY+g0dnHkH8N7t+VKjPPnihlX
 WBaT0Y4SzMsfAtG5lQqS48A50dXKWW70QvwkZjxu7abQhYFWGd2SGtTQxwqJXT8J
 I6MBh4r9xrIfiqzVT2BXslA6id5H6wCyyFI6vKm/IFkIu1J6JtwnKakQ0CIddS1d
 Blbgj5jcxGw+2xOppHCQXbWwwDdmYWkMZEBZjmhkezddqLDK+oaAUiUhHHHizTsB
 kLjgqYBVENpR1zDIsGpQAJloKXAiHfBQshQAmnhnBNzXE60LZ0n0/iODU9U5FDEO
 5j0DRWccKvsIMsUh7JpPr5xerGJ0rqk1IwPC2JcyzfRbvRLMpK1IOWfhI5Tg5lbP
 4Ev96QLEMBnKOWMSE0MqnMdq6JPzDLA6WZ28HZe2nc3/oWNgsSDtlXigx4xFFxTX
 zfc2YpAgFu3xJkPf8PtWTFvItm0AvFNFynPg0Rr/NsGf/FGeszYR4cLcHmv5NlWS
 IiV4+lgnlmr2LZr3VjUaumbtWIpuVF4Db5Al2K2E/PCN7ObfEkyCweDic8ophkH8
 sMS9TI38aH1Efy+I2Nfxxqpy8BcElZAMrAWt9R27A4JRLHdr7j5DsGnyRigXHgRe
 pFgbqtk/EjWkHwjaJVg8kPxf2+2P05VZsQeGG721nbKAIKDetM3RA2BflexdsptY
 kXplNsVr
 =eILh
 -----END PGP SIGNATURE-----

Merge tag 'kvmarm-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm updates for Linux 5.7

- GICv4.1 support
- 32bit host removal
2020-03-31 10:44:53 -04:00
Linus Torvalds
9b82f05f86 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "The main changes in this cycle were:

  Kernel side changes:

   - A couple of x86/cpu cleanups and changes were grandfathered in due
     to patch dependencies. These clean up the set of CPU model/family
     matching macros with a consistent namespace and C99 initializer
     style.

   - A bunch of updates to various low level PMU drivers:
       * AMD Family 19h L3 uncore PMU
       * Intel Tiger Lake uncore support
       * misc fixes to LBR TOS sampling

   - optprobe fixes

   - perf/cgroup: optimize cgroup event sched-in processing

   - misc cleanups and fixes

  Tooling side changes are to:

   - perf {annotate,expr,record,report,stat,test}

   - perl scripting

   - libapi, libperf and libtraceevent

   - vendor events on Intel and S390, ARM cs-etm

   - Intel PT updates

   - Documentation changes and updates to core facilities

   - misc cleanups, fixes and other enhancements"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (89 commits)
  cpufreq/intel_pstate: Fix wrong macro conversion
  x86/cpu: Cleanup the now unused CPU match macros
  hwrng: via_rng: Convert to new X86 CPU match macros
  crypto: Convert to new CPU match macros
  ASoC: Intel: Convert to new X86 CPU match macros
  powercap/intel_rapl: Convert to new X86 CPU match macros
  PCI: intel-mid: Convert to new X86 CPU match macros
  mmc: sdhci-acpi: Convert to new X86 CPU match macros
  intel_idle: Convert to new X86 CPU match macros
  extcon: axp288: Convert to new X86 CPU match macros
  thermal: Convert to new X86 CPU match macros
  hwmon: Convert to new X86 CPU match macros
  platform/x86: Convert to new CPU match macros
  EDAC: Convert to new X86 CPU match macros
  cpufreq: Convert to new X86 CPU match macros
  ACPI: Convert to new X86 CPU match macros
  x86/platform: Convert to new CPU match macros
  x86/kernel: Convert to new CPU match macros
  x86/kvm: Convert to new CPU match macros
  x86/perf/events: Convert to new CPU match macros
  ...
2020-03-30 16:40:08 -07:00
Ingo Molnar
629b3df7ec Merge branch 'x86/cpu' into perf/core, to resolve conflict
Conflicts:
	arch/x86/events/intel/uncore.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-03-25 15:20:44 +01:00
Thomas Gleixner
320debe5ef x86/kvm: Convert to new CPU match macros
The new macro set has a consistent namespace and uses C99 initializers
instead of the grufty C89 ones.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lkml.kernel.org/r/20200320131509.136884777@linutronix.de
2020-03-24 21:27:29 +01:00
Thomas Gleixner
ba5bade4cc x86/devicetable: Move x86 specific macro out of generic code
There is no reason that this gunk is in a generic header file. The wildcard
defines need to stay as they are required by file2alias.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lkml.kernel.org/r/20200320131508.736205164@linutronix.de
2020-03-24 21:02:47 +01:00
Sean Christopherson
4f6ea0a876 KVM: VMX: Gracefully handle faults on VMXON
Gracefully handle faults on VMXON, e.g. #GP due to VMX being disabled by
BIOS, instead of letting the fault crash the system.  Now that KVM uses
cpufeatures to query support instead of reading MSR_IA32_FEAT_CTL
directly, it's possible for a bug in a different subsystem to cause KVM
to incorrectly attempt VMXON[*].  Crashing the system is especially
annoying if the system is configured such that hardware_enable() will
be triggered during boot.

Oppurtunistically rename @addr to @vmxon_pointer and use a named param
to reference it in the inline assembly.

Print 0xdeadbeef in the ultra-"rare" case that reading MSR_IA32_FEAT_CTL
also faults.

[*] https://lkml.kernel.org/r/20200226231615.13664-1-sean.j.christopherson@intel.com
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321193751.24985-4-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:26 -04:00
Sean Christopherson
d260f9ef50 KVM: VMX: Fold loaded_vmcs_init() into alloc_loaded_vmcs()
Subsume loaded_vmcs_init() into alloc_loaded_vmcs(), its only remaining
caller, and drop the VMCLEAR on the shadow VMCS, which is guaranteed to
be NULL.  loaded_vmcs_init() was previously used by loaded_vmcs_clear(),
but loaded_vmcs_clear() also subsumed loaded_vmcs_init() to properly
handle smp_wmb() with respect to VMCLEAR.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321193751.24985-3-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:26 -04:00
Sean Christopherson
31603d4fc2 KVM: VMX: Always VMCLEAR in-use VMCSes during crash with kexec support
VMCLEAR all in-use VMCSes during a crash, even if kdump's NMI shootdown
interrupted a KVM update of the percpu in-use VMCS list.

Because NMIs are not blocked by disabling IRQs, it's possible that
crash_vmclear_local_loaded_vmcss() could be called while the percpu list
of VMCSes is being modified, e.g. in the middle of list_add() in
vmx_vcpu_load_vmcs().  This potential corner case was called out in the
original commit[*], but the analysis of its impact was wrong.

Skipping the VMCLEARs is wrong because it all but guarantees that a
loaded, and therefore cached, VMCS will live across kexec and corrupt
memory in the new kernel.  Corruption will occur because the CPU's VMCS
cache is non-coherent, i.e. not snooped, and so the writeback of VMCS
memory on its eviction will overwrite random memory in the new kernel.
The VMCS will live because the NMI shootdown also disables VMX, i.e. the
in-progress VMCLEAR will #UD, and existing Intel CPUs do not flush the
VMCS cache on VMXOFF.

Furthermore, interrupting list_add() and list_del() is safe due to
crash_vmclear_local_loaded_vmcss() using forward iteration.  list_add()
ensures the new entry is not visible to forward iteration unless the
entire add completes, via WRITE_ONCE(prev->next, new).  A bad "prev"
pointer could be observed if the NMI shootdown interrupted list_del() or
list_add(), but list_for_each_entry() does not consume ->prev.

In addition to removing the temporary disabling of VMCLEAR, open code
loaded_vmcs_init() in __loaded_vmcs_clear() and reorder VMCLEAR so that
the VMCS is deleted from the list only after it's been VMCLEAR'd.
Deleting the VMCS before VMCLEAR would allow a race where the NMI
shootdown could arrive between list_del() and vmcs_clear() and thus
neither flow would execute a successful VMCLEAR.  Alternatively, more
code could be moved into loaded_vmcs_init(), but that gets rather silly
as the only other user, alloc_loaded_vmcs(), doesn't need the smp_wmb()
and would need to work around the list_del().

Update the smp_*() comments related to the list manipulation, and
opportunistically reword them to improve clarity.

[*] https://patchwork.kernel.org/patch/1675731/#3720461

Fixes: 8f536b7697a0 ("KVM: VMX: provide the vmclear function and a bitmap to support VMCLEAR in kdump")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200321193751.24985-2-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:44:25 -04:00
Nick Desaulniers
428b8f1d9f KVM: VMX: don't allow memory operands for inline asm that modifies SP
THUNK_TARGET defines [thunk_target] as having "rm" input constraints
when CONFIG_RETPOLINE is not set, which isn't constrained enough for
this specific case.

For inline assembly that modifies the stack pointer before using this
input, the underspecification of constraints is dangerous, and results
in an indirect call to a previously pushed flags register.

In this case `entry`'s stack slot is good enough to satisfy the "m"
constraint in "rm", but the inline assembly in
handle_external_interrupt_irqoff() modifies the stack pointer via
push+pushf before using this input, which in this case results in
calling what was the previous state of the flags register, rather than
`entry`.

Be more specific in the constraints by requiring `entry` be in a
register, and not a memory operand.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: syzbot+3f29ca2efb056a761e38@syzkaller.appspotmail.com
Debugged-by: Alexander Potapenko <glider@google.com>
Debugged-by: Paolo Bonzini <pbonzini@redhat.com>
Debugged-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Message-Id: <20200323191243.30002-1-ndesaulniers@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-23 15:40:51 -04:00
Paolo Bonzini
96b100cd14 KVM: nVMX: remove side effects from nested_vmx_exit_reflected
The name of nested_vmx_exit_reflected suggests that it's purely
a test, but it actually marks VMCS12 pages as dirty.  Move this to
vmx_handle_exit, observing that the initial nested_run_pending check in
nested_vmx_exit_reflected is pointless---nested_run_pending has just
been cleared in vmx_vcpu_run and won't be set until handle_vmlaunch
or handle_vmresume.

Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-18 12:16:39 +01:00
Wanpeng Li
041bc42ce2 KVM: VMX: Micro-optimize vmexit time when not exposing PMU
PMU is not exposed to guest by most of products from cloud providers since the
bad performance of PMU emulation and security concern. However, it calls
perf_guest_switch_get_msrs() and clear_atomic_switch_msr() unconditionally
even if PMU is not exposed to the guest before each vmentry.

~2% vmexit time reduced can be observed by kvm-unit-tests/vmexit.flat on my
SKX server.

Before patch:
vmcall 1559

After patch:
vmcall 1529

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:58 +01:00
Paolo Bonzini
727a7e27cf KVM: x86: rename set_cr3 callback and related flags to load_mmu_pgd
The set_cr3 callback is not setting the guest CR3, it is setting the
root of the guest page tables, either shadow or two-dimensional.
To make this clearer as well as to indicate that the MMU calls it
via kvm_mmu_load_cr3, rename it to load_mmu_pgd.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:52 +01:00
Paolo Bonzini
689f3bf216 KVM: x86: unify callbacks to load paging root
Similar to what kvm-intel.ko is doing, provide a single callback that
merges svm_set_cr3, set_tdp_cr3 and nested_svm_set_tdp_cr3.

This lets us unify the set_cr3 and set_tdp_cr3 entries in kvm_x86_ops.
I'm doing that in this same patch because splitting it adds quite a bit
of churn due to the need for forward declarations.  For the same reason
the assignment to vcpu->arch.mmu->set_cr3 is moved to kvm_init_shadow_mmu
from init_kvm_softmmu and nested_svm_init_mmu_context.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:51 +01:00
Paolo Bonzini
408e9a318f KVM: CPUID: add support for supervisor states
Current CPUID 0xd enumeration code does not support supervisor
states, because KVM only supports setting IA32_XSS to zero.
Change it instead to use a new variable supported_xss, to be
set from the hardware_setup callback which is in charge of CPU
capabilities.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:45 +01:00
Sean Christopherson
257038745c KVM: x86: Move nSVM CPUID 0x8000000A handling into common x86 code
Handle CPUID 0x8000000A in the main switch in __do_cpuid_func() and drop
->set_supported_cpuid() now that both VMX and SVM implementations are
empty.  Like leaf 0x14 (Intel PT) and leaf 0x8000001F (SEV), leaf
0x8000000A is is (obviously) vendor specific but can be queried in
common code while respecting SVM's wishes by querying kvm_cpu_cap_has().

Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:45 +01:00
Sean Christopherson
91661989d1 KVM: x86: Move VMX's host_efer to common x86 code
Move host_efer to common x86 code and use it for CPUID's is_efer_nx() to
avoid constantly re-reading the MSR.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:42 +01:00
Sean Christopherson
e884b854ee KVM: x86: Don't propagate MMU lpage support to memslot.disallow_lpage
Stop propagating MMU large page support into a memslot's disallow_lpage
now that the MMU's max_page_level handles the scenario where VMX's EPT is
enabled and EPT doesn't support 2M pages.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:41 +01:00
Sean Christopherson
703c335d06 KVM: x86/mmu: Configure max page level during hardware setup
Configure the max page level during hardware setup to avoid a retpoline
in the page fault handler.  Drop ->get_lpage_level() as the page fault
handler was the last user.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:40 +01:00
Sean Christopherson
bde7723559 KVM: x86/mmu: Merge kvm_{enable,disable}_tdp() into a common function
Combine kvm_enable_tdp() and kvm_disable_tdp() into a single function,
kvm_configure_mmu(), in preparation for doing additional configuration
during hardware setup.  And because having separate helpers is silly.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:39 +01:00
Sean Christopherson
a1bead2aba KVM: VMX: Directly query Intel PT mode when refreshing PMUs
Use vmx_pt_mode_is_host_guest() in intel_pmu_refresh() instead of
bouncing through kvm_x86_ops->pt_supported, and remove ->pt_supported()
as the PMU code was the last remaining user.

Opportunistically clean up the wording of a comment that referenced
kvm_x86_ops->pt_supported().

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:38 +01:00
Sean Christopherson
a7a200eb4c KVM: VMX: Directly use VMX capabilities helper to detect RDTSCP support
Use cpu_has_vmx_rdtscp() directly when computing secondary exec controls
and drop the now defunct vmx_rdtscp_supported().

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:36 +01:00
Sean Christopherson
139085101f KVM: x86: Use KVM cpu caps to detect MSR_TSC_AUX virt support
Check for MSR_TSC_AUX virtualization via kvm_cpu_cap_has() and drop
->rdtscp_supported().

Note, vmx_rdtscp_supported() needs to hang around a tiny bit longer due
other usage in VMX code.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:35 +01:00
Sean Christopherson
93c380e7b5 KVM: x86: Set emulated/transmuted feature bits via kvm_cpu_caps
Set emulated and transmuted (set based on other features) feature bits
via kvm_cpu_caps now that the CPUID output for KVM_GET_SUPPORTED_CPUID
is direcly overidden with kvm_cpu_caps.

Note, VMX emulation of UMIP already sets kvm_cpu_caps.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:33 +01:00
Sean Christopherson
bd79199990 KVM: x86: Override host CPUID results with kvm_cpu_caps
Override CPUID entries with kvm_cpu_caps during KVM_GET_SUPPORTED_CPUID
instead of masking the host CPUID result, which is redundant now that
the host CPUID is incorporated into kvm_cpu_caps at runtime.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:32 +01:00
Sean Christopherson
90d2f60f41 KVM: x86: Use KVM cpu caps to track UMIP emulation
Set UMIP in kvm_cpu_caps when it is emulated by VMX, even though the
bit will effectively be dropped by do_host_cpuid().  This allows
checking for UMIP emulation via kvm_cpu_caps instead of a dedicated
kvm_x86_ops callback.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:28 +01:00
Sean Christopherson
8721f5b061 KVM: x86: Add a helper to check kernel support when setting cpu cap
Add a helper, kvm_cpu_cap_check_and_set(), to query boot_cpu_has() as
part of setting a KVM cpu capability.  VMX in particular has a number of
features that are dependent on both a VMCS capability and kernel
support.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:26 +01:00
Sean Christopherson
b3d895d5c4 KVM: x86: Move XSAVES CPUID adjust to VMX's KVM cpu cap update
Move the clearing of the XSAVES CPUID bit into VMX, which has a separate
VMCS control to enable XSAVES in non-root, to eliminate the last ugly
renmant of the undesirable "unsigned f_* = *_supported ? F(*) : 0"
pattern in the common CPUID handling code.

Drop ->xsaves_supported(), CPUID adjustment was the only user.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:25 +01:00
Sean Christopherson
3ec6fd8cf0 KVM: VMX: Convert feature updates from CPUID to KVM cpu caps
Use the recently introduced KVM CPU caps to propagate VMX-only (kernel)
settings to supported CPUID flags.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:24 +01:00
Sean Christopherson
66a6950f99 KVM: x86: Introduce kvm_cpu_caps to replace runtime CPUID masking
Calculate the CPUID masks for KVM_GET_SUPPORTED_CPUID at load time using
what is effectively a KVM-adjusted copy of boot_cpu_data, or more
precisely, the x86_capability array in boot_cpu_data.

In terms of KVM support, the vast majority of CPUID feature bits are
constant, and *all* feature support is known at KVM load time.  Rather
than apply boot_cpu_data, which is effectively read-only after init,
at runtime, copy it into a KVM-specific array and use *that* to mask
CPUID registers.

In additional to consolidating the masking, kvm_cpu_caps can be adjusted
by SVM/VMX at load time and thus eliminate all feature bit manipulation
in ->set_supported_cpuid().

Opportunistically clean up a few warts:

  - Replace bare "unsigned" with "unsigned int" when a feature flag is
    captured in a local variable, e.g. f_nx.

  - Sort the CPUID masks by function, index and register (alphabetically
    for registers, i.e. EBX comes before ECX/EDX).

  - Remove the superfluous /* cpuid 7.0.ecx */ comments.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
[Call kvm_set_cpu_caps from kvm_x86_ops->hardware_setup due to fixed
 GBPAGES patch. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:23 +01:00
Sean Christopherson
dbd068040c KVM: x86: Handle Intel PT CPUID adjustment in VMX code
Move the Processor Trace CPUID adjustment into VMX code to eliminate
an instance of the undesirable "unsigned f_* = *_supported ? F(*) : 0"
pattern in the common CPUID handling code, and to pave the way toward
eventually removing ->pt_supported().

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:20 +01:00
Sean Christopherson
733deafc00 KVM: x86: Handle RDTSCP CPUID adjustment in VMX code
Move the clearing of the RDTSCP CPUID bit into VMX, which has a separate
VMCS control to enable RDTSCP in non-root, to eliminate an instance of
the undesirable "unsigned f_* = *_supported ? F(*) : 0" pattern in the
common CPUID handling code.  Drop ->rdtscp_supported() since CPUID
adjustment was the last remaining user.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:20 +01:00
Sean Christopherson
d64d83d1e0 KVM: x86: Handle PKU CPUID adjustment in VMX code
Move the setting of the PKU CPUID bit into VMX to eliminate an instance
of the undesirable "unsigned f_* = *_supported ? F(*) : 0" pattern in
the common CPUID handling code.  Drop ->pku_supported(), CPUID
adjustment was the only user.

Note, some AMD CPUs now support PKU, but SVM doesn't yet support
exposing it to a guest.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:19 +01:00
Sean Christopherson
e574768f84 KVM: x86: Handle UMIP emulation CPUID adjustment in VMX code
Move the CPUID adjustment for UMIP emulation into VMX code to eliminate
an instance of the undesirable "unsigned f_* = *_supported ? F(*) : 0"
pattern in the common CPUID handling code.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:18 +01:00
Sean Christopherson
5ffec6f910 KVM: x86: Handle INVPCID CPUID adjustment in VMX code
Move the INVPCID CPUID adjustments into VMX to eliminate an instance of
the undesirable "unsigned f_* = *_supported ? F(*) : 0" pattern in the
common CPUID handling code.  Drop ->invpcid_supported(), CPUID
adjustment was the only user.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:17 +01:00
Sean Christopherson
6c7ea4b56b KVM: x86: Handle MPX CPUID adjustment in VMX code
Move the MPX CPUID adjustments into VMX to eliminate an instance of the
undesirable "unsigned f_* = *_supported ? F(*) : 0" pattern in the
common CPUID handling code.

Note, to maintain existing behavior, VMX must manually check for kernel
support for MPX by querying boot_cpu_has(X86_FEATURE_MPX).  Previously,
do_cpuid_7_mask() masked MPX based on boot_cpu_data by invoking
cpuid_mask() on the associated cpufeatures word, but cpuid_mask() runs
prior to executing vmx_set_supported_cpuid().

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:17 +01:00
Sean Christopherson
160b486f65 KVM: x86: Drop explicit @func param from ->set_supported_cpuid()
Drop the explicit @func param from ->set_supported_cpuid() and instead
pull the CPUID function from the relevant entry.  This sets the stage
for hardening guest CPUID updates in future patches, e.g. allows adding
run-time assertions that the CPUID feature being changed is actually
a bit in the referenced CPUID entry.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:12 +01:00
Sean Christopherson
7f5581f592 KVM: x86: Use supported_xcr0 to detect MPX support
Query supported_xcr0 when checking for MPX support instead of invoking
->mpx_supported() and drop ->mpx_supported() as kvm_mpx_supported() was
its last user.  Rename vmx_mpx_supported() to cpu_has_vmx_mpx() to
better align with VMX/VMCS nomenclature.

Modify VMX's adjustment of xcr0 to call cpus_has_vmx_mpx() (renamed from
vmx_mpx_supported()) directly to avoid reading supported_xcr0 before
it's fully configured.

No functional change intended.

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
[Test that *all* bits are set. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:10 +01:00
Sean Christopherson
cfc481810c KVM: x86: Calculate the supported xcr0 mask at load time
Add a new global variable, supported_xcr0, to track which xcr0 bits can
be exposed to the guest instead of calculating the mask on every call.
The supported bits are constant for a given instance of KVM.

This paves the way toward eliminating the ->mpx_supported() call in
kvm_mpx_supported(), e.g. eliminates multiple retpolines in VMX's nested
VM-Enter path, and eventually toward eliminating ->mpx_supported()
altogether.

No functional change intended.

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 17:58:09 +01:00