Currently SVM setup is done sequentially in init_vmcb() -> sev_init_vmcb() -> sev_es_init_vmcb() and tries keeping SVM/SEV/SEV-ES bits separated. One of the exceptions is #GP intercept which init_vmcb() skips setting for SEV guests and then sev_es_init_vmcb() needlessly clears it. Remove the SEV check from init_vmcb(). Clear the #GP intercept in sev_init_vmcb(). SEV-ES will use the SEV setting. No functional change intended. Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxx> Reviewed-by: Carlos Bilbao <carlos.bilbao@xxxxxxx> Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx> Reviewed-by: Santosh Shukla <santosh.shukla@xxxxxxx> --- Changes: v5: * new in the series --- arch/x86/kvm/svm/sev.c | 9 ++++++--- arch/x86/kvm/svm/svm.c | 5 ++--- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 69ae5e1b3120..c03bd063aecf 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2971,9 +2971,6 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm) svm_set_intercept(svm, TRAP_CR4_WRITE); svm_set_intercept(svm, TRAP_CR8_WRITE); - /* No support for enable_vmware_backdoor */ - clr_exception_intercept(svm, GP_VECTOR); - /* Can't intercept XSETBV, HV can't modify XCR0 directly */ svm_clr_intercept(svm, INTERCEPT_XSETBV); @@ -2999,6 +2996,12 @@ void sev_init_vmcb(struct vcpu_svm *svm) svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE; clr_exception_intercept(svm, UD_VECTOR); + /* + * Don't intercept #GP for SEV guests, e.g. for the VMware backdoor, as + * KVM can't decrypt guest memory to decode the faulting instruction. + */ + clr_exception_intercept(svm, GP_VECTOR); + if (sev_es_guest(svm->vcpu.kvm)) sev_es_init_vmcb(svm); } diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 980faf460bfe..9c1b191aed4b 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1256,10 +1256,9 @@ static void init_vmcb(struct kvm_vcpu *vcpu) * Guest access to VMware backdoor ports could legitimately * trigger #GP because of TSS I/O permission bitmap. * We intercept those #GP and allow access to them anyway - * as VMware does. Don't intercept #GP for SEV guests as KVM can't - * decrypt guest memory to decode the faulting instruction. + * as VMware does. */ - if (enable_vmware_backdoor && !sev_guest(vcpu->kvm)) + if (enable_vmware_backdoor) set_exception_intercept(svm, GP_VECTOR); svm_set_intercept(svm, INTERCEPT_INTR); -- 2.40.1
