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| author |  Sean Christopherson <sean.j.christopherson@intel.com>
| 2020-03-04 17:34:32 -0800 |
|---|---|---|
| committer |  Paolo Bonzini <pbonzini@redhat.com>
| 2020-03-16 17:58:47 +0100 |
| commit | 15608ed03f10a1414188612b0ee9653e3c78bbd9 (patch) | |
| tree | ac09dad5dac942f2aece0e77a244c33326bdf0a8 /arch/x86/kvm/cpuid.h | |
| parent | KVM: x86: Trace the original requested CPUID function in kvm_cpuid() (diff) | |
| download | linux-15608ed03f10a1414188612b0ee9653e3c78bbd9.tar.gz linux-15608ed03f10a1414188612b0ee9653e3c78bbd9.tar.bz2 linux-15608ed03f10a1414188612b0ee9653e3c78bbd9.zip | |
KVM: x86: Add helpers to perform CPUID-based guest vendor check
Add helpers to provide CPUID-based guest vendor checks, i.e. to do the
ugly register comparisons. Use the new helpers to check for an AMD
guest vendor in guest_cpuid_is_amd() as well as in the existing emulator
flows.
Using the new helpers fixes a _very_ theoretical bug where
guest_cpuid_is_amd() would get a false positive on a non-AMD virtual CPU
with a vendor string beginning with "Auth" due to the previous logic
only checking EBX. It also fixes a marginally less theoretically bug
where guest_cpuid_is_amd() would incorrectly return false for a guest
CPU with "AMDisbetter!" as its vendor string.
Fixes: a0c0feb57992c ("KVM: x86: reserve bit 8 of non-leaf PDPEs and PML4Es in 64-bit mode on AMD")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/cpuid.h')
| -rw-r--r-- | arch/x86/kvm/cpuid.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index e9a3277ce256..cccfd854aacf 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -219,7 +219,7 @@ static inline bool guest_cpuid_is_amd(struct kvm_vcpu *vcpu) struct kvm_cpuid_entry2 *best; best = kvm_find_cpuid_entry(vcpu, 0, 0); - return best && best->ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx; + return best && is_guest_vendor_amd(best->ebx, best->ecx, best->edx); } static inline int guest_cpuid_family(struct kvm_vcpu *vcpu) |