| Message ID | 20210820155918.7518-44-brijesh.singh@amd.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support | expand |
On Fri, Aug 20, 2021, Brijesh Singh wrote: > From: Tom Lendacky <thomas.lendacky@amd.com> > > In preparation to support SEV-SNP AP Creation, use a variable that holds > the VMSA physical address rather than converting the virtual address. > This will allow SEV-SNP AP Creation to set the new physical address that > will be used should the vCPU reset path be taken. The use of "variable" in the changelog and shortlog is really confusing. I read them multiple times and still didn't fully understand the change until I sussed out that the change is to track the PA in vcpu_svm separately from vcpu_svm.vmsa. It's somewhat of a moot point though, because I think this can and should be simplified. In the SEV-ES case, svm->vmcb->control.vmsa_pa is always __pa(svm->vmsa). And in the SNP case, svm->vmcb->control.vmsa_pa defaults to __pa(svm->vmsa), but is not changed on INIT. Rather than do this crazy 3-way dance, simply don't write svm->vmcb->control.vmsa_pa on INIT. Then SNP can change it at will without having an unnecessary and confusing field. diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 1e8b26b93b4f..0bec0b71577e 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2593,13 +2593,6 @@ void sev_es_init_vmcb(struct vcpu_svm *svm) svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE; svm->vmcb->control.virt_ext |= LBR_CTL_ENABLE_MASK; - /* - * An SEV-ES guest requires a VMSA area that is a separate from the - * VMCB page. Do not include the encryption mask on the VMSA physical - * address since hardware will access it using the guest key. - */ - svm->vmcb->control.vmsa_pa = __pa(svm->vmsa); - /* Can't intercept CR register access, HV can't modify CR registers */ svm_clr_intercept(svm, INTERCEPT_CR0_READ); svm_clr_intercept(svm, INTERCEPT_CR4_READ); @@ -2633,6 +2626,13 @@ void sev_es_init_vmcb(struct vcpu_svm *svm) void sev_es_vcpu_reset(struct vcpu_svm *svm) { + /* + * An SEV-ES guest requires a VMSA area that is a separate from the + * VMCB page. Do not include the encryption mask on the VMSA physical + * address since hardware will access it using the guest key. + */ + svm->vmcb->control.vmsa_pa = __pa(svm->vmsa); + /* * Set the GHCB MSR value as per the GHCB specification when emulating * vCPU RESET for an SEV-ES guest. > Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> This needs your SoB.
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 81ccad412e55..05f795c30816 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -3619,10 +3619,9 @@ void sev_es_init_vmcb(struct vcpu_svm *svm) /* * An SEV-ES guest requires a VMSA area that is a separate from the - * VMCB page. Do not include the encryption mask on the VMSA physical - * address since hardware will access it using the guest key. + * VMCB page. */ - svm->vmcb->control.vmsa_pa = __pa(svm->vmsa); + svm->vmcb->control.vmsa_pa = svm->vmsa_pa; /* Can't intercept CR register access, HV can't modify CR registers */ svm_clr_intercept(svm, INTERCEPT_CR0_READ); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 3ba62f21b113..be820eb999fb 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1409,9 +1409,16 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) svm->vmcb01.ptr = page_address(vmcb01_page); svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT); - if (vmsa_page) + if (vmsa_page) { svm->vmsa = page_address(vmsa_page); + /* + * Do not include the encryption mask on the VMSA physical + * address since hardware will access it using the guest key. + */ + svm->vmsa_pa = __pa(svm->vmsa); + } + svm->guest_state_loaded = false; svm_switch_vmcb(svm, &svm->vmcb01); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 71fe46a778f3..9bf6404142dd 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -199,6 +199,7 @@ struct vcpu_svm { /* SEV-ES support */ struct sev_es_save_area *vmsa; + hpa_t vmsa_pa; bool ghcb_in_use; bool received_first_sipi; unsigned int ap_reset_hold_type;