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[v3,3/4] KVM: SVM: Add support for Hypervisor Feature support MSR protocol

Message ID 20210913141345.27175-4-joro@8bytes.org (mailing list archive)
State New, archived
Headers show
Series KVM: SVM: Add initial GHCB protocol version 2 support | expand

Commit Message

Joerg Roedel Sept. 13, 2021, 2:13 p.m. UTC 
From: Brijesh Singh <brijesh.singh@amd.com>

Version 2 of the GHCB specification introduced advertisement of
supported Hypervisor SEV features. This request is required to support
a the GHCB version 2 protocol.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/include/uapi/asm/svm.h |  1 +
 arch/x86/kvm/svm/sev.c          | 19 +++++++++++++++++++
 arch/x86/kvm/svm/svm.h          |  1 +
 3 files changed, 21 insertions(+)

Comments

Sean Christopherson Sept. 24, 2021, 8:11 p.m. UTC | #1 
On Mon, Sep 13, 2021, Joerg Roedel wrote:
> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> index 524d943f3efc..f019da28ff06 100644
> --- a/arch/x86/kvm/svm/svm.h
> +++ b/arch/x86/kvm/svm/svm.h
> @@ -542,6 +542,7 @@ void svm_vcpu_unblocking(struct kvm_vcpu *vcpu);
>  #define GHCB_VERSION_MAX	1ULL
>  #define GHCB_VERSION_MIN	1ULL
>  
> +#define GHCB_HV_FT_SUPPORTED	0

I'd prefer to keep these SEV-only defines in sev.c.  I also think it should have
KVM somewhere in the name, a la KVM_SUPPORTED_XCR0, e.g. KVM_SUPPORTED_GHCB_FEATURES?
diff mbox series

Patch

diff --git a/arch/x86/include/uapi/asm/svm.h b/arch/x86/include/uapi/asm/svm.h
index efa969325ede..67cf153fe580 100644
--- a/arch/x86/include/uapi/asm/svm.h
+++ b/arch/x86/include/uapi/asm/svm.h
@@ -108,6 +108,7 @@ 
 #define SVM_VMGEXIT_AP_JUMP_TABLE		0x80000005
 #define SVM_VMGEXIT_SET_AP_JUMP_TABLE		0
 #define SVM_VMGEXIT_GET_AP_JUMP_TABLE		1
+#define SVM_VMGEXIT_HYPERVISOR_FEATURES		0x8000fffd
 #define SVM_VMGEXIT_UNSUPPORTED_EVENT		0x8000ffff
 
 /* Exit code reserved for hypervisor/software use */
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 8cd1e4ebb4a8..b3fdfccf0499 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_HYPERVISOR_FEATURES:
 		break;
 	default:
 		goto vmgexit_err;
@@ -2365,6 +2366,16 @@  static u64 ghcb_msr_ap_rst_resp(u64 value)
 	return (u64)GHCB_MSR_AP_RESET_HOLD_RESP | (value << GHCB_DATA_LOW);
 }
 
+static u64 ghcb_msr_hv_feat_resp(u64 value)
+{
+	u64 msr;
+
+	msr  = GHCB_MSR_HV_FT_RESP;
+	msr |= (value << GHCB_DATA_LOW);
+
+	return msr;
+}
+
 static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
 {
 	struct vmcb_control_area *control = &svm->vmcb->control;
@@ -2422,6 +2433,9 @@  static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
 		 */
 		svm->vmcb->control.ghcb_gpa = ghcb_msr_ap_rst_resp(0);
 
+		break;
+	case GHCB_MSR_HV_FT_REQ:
+		svm->vmcb->control.ghcb_gpa = ghcb_msr_hv_feat_resp(GHCB_HV_FT_SUPPORTED);
 		break;
 	case GHCB_MSR_TERM_REQ: {
 		u64 reason_set, reason_code;
@@ -2535,6 +2549,11 @@  int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
 		ret = 1;
 		break;
 	}
+	case SVM_VMGEXIT_HYPERVISOR_FEATURES:
+		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",
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 524d943f3efc..f019da28ff06 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -542,6 +542,7 @@  void svm_vcpu_unblocking(struct kvm_vcpu *vcpu);
 #define GHCB_VERSION_MAX	1ULL
 #define GHCB_VERSION_MIN	1ULL
 
+#define GHCB_HV_FT_SUPPORTED	0
 
 extern unsigned int max_sev_asid;