On Thu, 2021-01-21 at 01:55 -0500, Wei Huang wrote: > New AMD CPUs have a change that checks VMEXIT intercept on special SVM > instructions before checking their EAX against reserved memory region. > This change is indicated by CPUID_0x8000000A_EDX[28]. If it is 1, #VMEXIT > is triggered before #GP. KVM doesn't need to intercept and emulate #GP > faults as #GP is supposed to be triggered. > > Co-developed-by: Bandan Das <bsd@xxxxxxxxxx> > Signed-off-by: Bandan Das <bsd@xxxxxxxxxx> > Signed-off-by: Wei Huang <wei.huang2@xxxxxxx> > --- > arch/x86/include/asm/cpufeatures.h | 1 + > arch/x86/kvm/svm/svm.c | 6 +++++- > 2 files changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h > index 84b887825f12..ea89d6fdd79a 100644 > --- a/arch/x86/include/asm/cpufeatures.h > +++ b/arch/x86/include/asm/cpufeatures.h > @@ -337,6 +337,7 @@ > #define X86_FEATURE_AVIC (15*32+13) /* Virtual Interrupt Controller */ > #define X86_FEATURE_V_VMSAVE_VMLOAD (15*32+15) /* Virtual VMSAVE VMLOAD */ > #define X86_FEATURE_VGIF (15*32+16) /* Virtual GIF */ > +#define X86_FEATURE_SVME_ADDR_CHK (15*32+28) /* "" SVME addr check */ > > /* Intel-defined CPU features, CPUID level 0x00000007:0 (ECX), word 16 */ > #define X86_FEATURE_AVX512VBMI (16*32+ 1) /* AVX512 Vector Bit Manipulation instructions*/ > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index 6ed523cab068..2a12870ac71a 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -313,7 +313,8 @@ int svm_set_efer(struct kvm_vcpu *vcpu, u64 efer) > svm->vmcb->save.efer = efer | EFER_SVME; > vmcb_mark_dirty(svm->vmcb, VMCB_CR); > /* Enable #GP interception for SVM instructions */ > - set_exception_intercept(svm, GP_VECTOR); > + if (!kvm_cpu_cap_has(X86_FEATURE_SVME_ADDR_CHK)) > + set_exception_intercept(svm, GP_VECTOR); > > return 0; > } > @@ -933,6 +934,9 @@ static __init void svm_set_cpu_caps(void) > boot_cpu_has(X86_FEATURE_AMD_SSBD)) > kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD); > > + if (boot_cpu_has(X86_FEATURE_SVME_ADDR_CHK)) > + kvm_cpu_cap_set(X86_FEATURE_SVME_ADDR_CHK); > + > /* Enable INVPCID feature */ > kvm_cpu_cap_check_and_set(X86_FEATURE_INVPCID); > } Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> Best regards, Maxim Levitsky
