Re: [PATCH Part2 v5 20/45] KVM: SVM: Provide the Hypervisor Feature support VMGEXIT

Sean Christopherson
2021-10-12T20:38:28Z

On Fri, Aug 20, 2021, Brijesh Singh wrote:
> Version 2 of the GHCB specification introduced advertisement of features
> that are supported by the Hypervisor.
>
> Now that KVM supports version 2 of the GHCB specification, bump the
> maximum supported protocol version.
>
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
> arch/x86/include/asm/sev-common.h | 2 ++
> arch/x86/kvm/svm/sev.c | 14 ++++++++++++++
> arch/x86/kvm/svm/svm.h | 3 ++-
> 3 files changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
> index d70a19000953..779c7e8f836c 100644
> --- a/arch/x86/include/asm/sev-common.h
> +++ b/arch/x86/include/asm/sev-common.h
> @@ -97,6 +97,8 @@ enum psc_op {
> /* GHCB Hypervisor Feature Request/Response */
> #define GHCB_MSR_HV_FT_REQ 0x080
> #define GHCB_MSR_HV_FT_RESP 0x081
> +#define GHCB_MSR_HV_FT_POS 12
> +#define GHCB_MSR_HV_FT_MASK GENMASK_ULL(51, 0)
> #define GHCB_MSR_HV_FT_RESP_VAL(v) \
> /* GHCBData[63:12] */ \
> (((u64)(v) & GENMASK_ULL(63, 12)) >> 12)
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 0ca5b5b9aeef..1644da5fc93f 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -2184,6 +2184,7 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
> case SVM_VMGEXIT_AP_HLT_LOOP:
> case SVM_VMGEXIT_AP_JUMP_TABLE:
> case SVM_VMGEXIT_UNSUPPORTED_EVENT:
> + case SVM_VMGEXIT_HV_FEATURES:
> break;
> default:
> goto vmgexit_err;
> @@ -2438,6 +2439,13 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
> GHCB_MSR_INFO_MASK,
> GHCB_MSR_INFO_POS);
> break;
> + case GHCB_MSR_HV_FT_REQ: {

Unnecessary braces.

> + set_ghcb_msr_bits(svm, GHCB_HV_FT_SUPPORTED,
> + GHCB_MSR_HV_FT_MASK, GHCB_MSR_HV_FT_POS);
> + set_ghcb_msr_bits(svm, GHCB_MSR_HV_FT_RESP,
> + GHCB_MSR_INFO_MASK, GHCB_MSR_INFO_POS);
> + break;
> + }
> case GHCB_MSR_TERM_REQ: {
> u64 reason_set, reason_code;
>
> @@ -2553,6 +2561,12 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
> ret = 1;
> break;
> }
> + case SVM_VMGEXIT_HV_FEATURES: {

Same here.

> + ghcb_set_sw_exit_info_2(ghcb, GHCB_HV_FT_SUPPORTED);
> +
> + ret = 1;
> + break;
> + }
> case SVM_VMGEXIT_UNSUPPORTED_EVENT:
> vcpu_unimpl(vcpu,
> "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",