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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-03-03 02:56:23 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-16 19:58:09 +0300 |
| commit | cfc481810c903a5f74e5c7bf50ca8e28318dbc44 (patch) | |
| tree | 2f618589dd4f45024f5211dd0e9a627c24b354b7 /arch/x86/kvm/x86.c | |
| parent | 2ef7619d43731b6eaa7cc2e03d000e4bbc1bf612 (diff) | |
| download | linux-cfc481810c903a5f74e5c7bf50ca8e28318dbc44.tar.xz | |
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>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a69f7bf020d9..849957f3afb2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -181,6 +181,11 @@ struct kvm_shared_msrs { static struct kvm_shared_msrs_global __read_mostly shared_msrs_global; static struct kvm_shared_msrs __percpu *shared_msrs; +#define KVM_SUPPORTED_XCR0 (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \ + | XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \ + | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \ + | XFEATURE_MASK_PKRU) + static u64 __read_mostly host_xss; struct kvm_stats_debugfs_item debugfs_entries[] = { @@ -227,6 +232,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { }; u64 __read_mostly host_xcr0; +u64 __read_mostly supported_xcr0; +EXPORT_SYMBOL_GPL(supported_xcr0); struct kmem_cache *x86_fpu_cache; EXPORT_SYMBOL_GPL(x86_fpu_cache); @@ -4114,8 +4121,7 @@ static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu, * CPUID leaf 0xD, index 0, EDX:EAX. This is for compatibility * with old userspace. */ - if (xstate_bv & ~kvm_supported_xcr0() || - mxcsr & ~mxcsr_feature_mask) + if (xstate_bv & ~supported_xcr0 || mxcsr & ~mxcsr_feature_mask) return -EINVAL; load_xsave(vcpu, (u8 *)guest_xsave->region); } else { @@ -7352,8 +7358,10 @@ int kvm_arch_init(void *opaque) perf_register_guest_info_callbacks(&kvm_guest_cbs); - if (boot_cpu_has(X86_FEATURE_XSAVE)) + if (boot_cpu_has(X86_FEATURE_XSAVE)) { host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK); + supported_xcr0 = host_xcr0 & KVM_SUPPORTED_XCR0; + } kvm_lapic_init(); if (pi_inject_timer == -1) |