Messages in this thread | | | Date | Thu, 22 Dec 2022 19:03:26 +0800 | Subject | Re: [PATCH v2 15/15] KVM: x86/cpuid: Advertise Arch LBR feature in CPUID | From | Like Xu <> |
| |
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.
> + cpuid_count(0x1c, 0, &eax, &ebx, &ecx, &edx); > + > + if ((eax & 0xff) && > + (best->eax & 0xff) != BIT(fls(eax & 0xff) - 1)) > + return -EINVAL; > + } > + }
| |