Messages in this thread | | | Date | Sun, 25 Dec 2022 12:31:21 +0800 | Subject | Re: [PATCH v2 15/15] KVM: x86/cpuid: Advertise Arch LBR feature in CPUID | From | "Yang, Weijiang" <> |
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On 12/22/2022 7:03 PM, Like Xu wrote: > On 25/11/2022 12:06 pm, Yang Weijiang wrote: >> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c >> index 85e3df6217af..60b3c591d462 100644 >> --- a/arch/x86/kvm/cpuid.c >> +++ b/arch/x86/kvm/cpuid.c >> @@ -134,6 +134,19 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu, >> if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) >> return -EINVAL; >> } >> + if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR)) { >> + best = cpuid_entry2_find(entries, nent, 0x1c, 0); >> + if (best) { >> + unsigned int eax, ebx, ecx, edx; >> + >> + /* Reject user-space CPUID if depth is different from >> host's.*/ > > Try to verify this in the KVM selftest, as this behavior is different > from the host.
Will do it.
> >> + cpuid_count(0x1c, 0, &eax, &ebx, &ecx, &edx); > + >> + if ((eax & 0xff) && >> + (best->eax & 0xff) != BIT(fls(eax & 0xff) - 1)) >> + return -EINVAL; >> + } >> + }
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