Svsm planes+SecureTSC

arch/x86/include/asm/cpufeatures.h

@@ -444,6 +444,7 @@
 #define X86_FEATURE_VM_PAGE_FLUSH	(19*32+ 2) /* VM Page Flush MSR is supported */
 #define X86_FEATURE_SEV_ES		(19*32+ 3) /* "sev_es" Secure Encrypted Virtualization - Encrypted State */
 #define X86_FEATURE_SEV_SNP		(19*32+ 4) /* "sev_snp" Secure Encrypted Virtualization - Secure Nested Paging */
+#define X86_FEATURE_SNP_SECURE_TSC	(19*32+ 8) /* SEV-SNP Secure TSC */
 #define X86_FEATURE_V_TSC_AUX		(19*32+ 9) /* Virtual TSC_AUX */
 #define X86_FEATURE_SME_COHERENT	(19*32+10) /* hardware-enforced cache coherency */
 #define X86_FEATURE_RESTRICTED_INJECTION	(19*32+12) /* AMD SEV Restricted Injection */

arch/x86/include/asm/svm.h

@@ -332,6 +332,7 @@ static_assert((X2AVIC_MAX_PHYSICAL_ID & AVIC_PHYSICAL_MAX_INDEX_MASK) == X2AVIC_
 #define SVM_SEV_FEAT_RESTRICTED_INJECTION		BIT(3)
 #define SVM_SEV_FEAT_ALTERNATE_INJECTION		BIT(4)
 #define SVM_SEV_FEAT_DEBUG_SWAP				BIT(5)
+#define SVM_SEV_FEAT_SECURE_TSC				BIT(9)
 
 #define VMCB_ALLOWED_SEV_FEATURES_VALID			BIT_ULL(63)
 

arch/x86/kvm/svm/sev.c

@@ -38,7 +38,6 @@
 #include "lapic.h"
 
 #define GHCB_VERSION_MAX	2ULL
-#define GHCB_VERSION_DEFAULT	2ULL
 #define GHCB_VERSION_MIN	1ULL
 
 #define GHCB_HV_FT_SUPPORTED	(GHCB_HV_FT_SNP			| \
@@ -154,6 +153,14 @@ static bool sev_vcpu_has_debug_swap(struct vcpu_svm *svm)
 	return svm->sev_es.vmsa_features & SVM_SEV_FEAT_DEBUG_SWAP;
 }
 
+static bool snp_is_secure_tsc_enabled(struct kvm *kvm)
+{
+	struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
+
+	return (sev->vmsa_features & SVM_SEV_FEAT_SECURE_TSC) &&
+	       !WARN_ON_ONCE(!sev_snp_guest(kvm));
+}
+
 /* Must be called with the sev_bitmap_lock held */
 static bool __sev_recycle_asids(unsigned int min_asid, unsigned int max_asid)
 {
@@ -413,6 +420,7 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp,
 	struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
 	struct sev_platform_init_args init_args = {0};
 	bool es_active = vm_type != KVM_X86_SEV_VM;
+	bool snp_active = vm_type == KVM_X86_SNP_VM;
 	u64 valid_vmsa_features = es_active ? sev_supported_vmsa_features : 0;
 	int ret;
 
@@ -422,12 +430,26 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp,
 	if (data->flags)
 		return -EINVAL;
 
+	if (!snp_active)
+		valid_vmsa_features &= ~SVM_SEV_FEAT_SECURE_TSC;
+
 	if (data->vmsa_features & ~valid_vmsa_features)
 		return -EINVAL;
 
 	if (data->ghcb_version > GHCB_VERSION_MAX || (!es_active && data->ghcb_version))
 		return -EINVAL;
 
+	/*
+	 * KVM supports the full range of mandatory features defined by version
+	 * 2 of the GHCB protocol, so default to that for SEV-ES guests created
+	 * via KVM_SEV_INIT2 (KVM_SEV_INIT forces version 1).
+	 */
+	if (es_active && !data->ghcb_version)
+		data->ghcb_version = 2;
+
+	if (snp_active && data->ghcb_version < 2)
+		return -EINVAL;
+
 	if (unlikely(sev->active))
 		return -EINVAL;
 
@@ -436,15 +458,7 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp,
 	sev->vmsa_features = data->vmsa_features;
 	sev->ghcb_version = data->ghcb_version;
 
-	/*
-	 * Currently KVM supports the full range of mandatory features defined
-	 * by version 2 of the GHCB protocol, so default to that for SEV-ES
-	 * guests created via KVM_SEV_INIT2.
-	 */
-	if (sev->es_active && !sev->ghcb_version)
-		sev->ghcb_version = GHCB_VERSION_DEFAULT;
-
-	if (vm_type == KVM_X86_SNP_VM)
+	if (snp_active)
 		sev->vmsa_features |= SVM_SEV_FEAT_SNP_ACTIVE;
 
 	ret = sev_asid_new(sev);
@@ -462,7 +476,7 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp,
 	}
 
 	/* This needs to happen after SEV/SNP firmware initialization. */
-	if (vm_type == KVM_X86_SNP_VM) {
+	if (snp_active) {
 		ret = snp_guest_req_init(kvm);
 		if (ret)
 			goto e_free;
@@ -1974,7 +1988,7 @@ static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm)
 	kvm_for_each_vcpu(i, dst_vcpu, dst_kvm) {
 		dst_svm = to_svm(dst_vcpu);
 
-		sev_init_vmcb(dst_svm);
+		sev_init_vmcb(dst_svm, false);
 
 		if (!dst->es_active)
 			continue;
@@ -2186,6 +2200,13 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (!(params.policy & SNP_POLICY_MASK_RSVD_MBO))
 		return -EINVAL;
 
+	if (snp_is_secure_tsc_enabled(kvm)) {
+		if (WARN_ON_ONCE(!kvm->arch.default_tsc_khz))
+			return -EINVAL;
+
+		start.desired_tsc_khz = kvm->arch.default_tsc_khz;
+	}
+
 	sev->policy = params.policy;
 
 	sev->snp_context = snp_context_create(kvm, argp);
@@ -2194,6 +2215,7 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 
 	start.gctx_paddr = __psp_pa(sev->snp_context);
 	start.policy = params.policy;
+
 	memcpy(start.gosvw, params.gosvw, sizeof(params.gosvw));
 	rc = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_LAUNCH_START, &start, &argp->error);
 	if (rc) {
@@ -3124,6 +3146,9 @@ void __init sev_hardware_setup(void)
 
 	if (sev_snp_restricted_injection_enabled)
 		sev_supported_vmsa_features |= SVM_SEV_FEAT_RESTRICTED_INJECTION;
+
+	if (sev_snp_enabled && tsc_khz && cpu_feature_enabled(X86_FEATURE_SNP_SECURE_TSC))
+		sev_supported_vmsa_features |= SVM_SEV_FEAT_SECURE_TSC;
 }
 
 void sev_hardware_unsetup(void)
@@ -3948,17 +3973,14 @@ static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc)
 /*
  * Invoked as part of svm_vcpu_reset() processing of an init event.
  */
-void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
+static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 	struct kvm_memory_slot *slot;
 	struct page *page;
 	kvm_pfn_t pfn;
 	gfn_t gfn;
 
-	if (!sev_snp_guest(vcpu->kvm))
-		return;
-
 	guard(mutex)(&svm->sev_es.snp_vmsa_mutex);
 
 	if (!svm->sev_es.snp_ap_waiting_for_reset)
@@ -4878,6 +4900,9 @@ void sev_es_recalc_msr_intercepts(struct kvm_vcpu *vcpu)
 					  !guest_cpu_cap_has(vcpu, X86_FEATURE_RDTSCP) &&
 					  !guest_cpu_cap_has(vcpu, X86_FEATURE_RDPID));
 
+	svm_set_intercept_for_msr(vcpu, MSR_AMD64_GUEST_TSC_FREQ, MSR_TYPE_R,
+				  !snp_is_secure_tsc_enabled(vcpu->kvm));
+
 	/*
 	 * For SEV-ES, accesses to MSR_IA32_XSS should not be intercepted if
 	 * the host/guest supports its use.
@@ -4915,8 +4940,9 @@ static void sev_snp_init_vmcb(struct vcpu_svm *svm)
 		svm->vmcb->control.int_ctl &= ~V_NMI_ENABLE_MASK;
 }
 
-static void sev_es_init_vmcb(struct vcpu_svm *svm)
+static void sev_es_init_vmcb(struct vcpu_svm *svm, bool init_event)
 {
+	struct kvm_sev_info *sev = to_kvm_sev_info(svm->vcpu.kvm);
 	struct vmcb *vmcb = svm->vmcb01.ptr;
 
 	svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ES_ENABLE;
@@ -4978,10 +5004,21 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
 
 	if (sev_snp_guest(svm->vcpu.kvm))
 		sev_snp_init_vmcb(svm);
+
+	/*
+	 * Set the GHCB MSR value as per the GHCB specification when emulating
+	 * vCPU RESET for an SEV-ES guest.
+	 */
+	if (!init_event)
+		set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version,
+						    GHCB_VERSION_MIN,
+						    sev_enc_bit));
 }
 
-void sev_init_vmcb(struct vcpu_svm *svm)
+void sev_init_vmcb(struct vcpu_svm *svm, bool init_event)
 {
+	struct kvm_vcpu *vcpu = &svm->vcpu;
+
 	svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE;
 	clr_exception_intercept(svm, UD_VECTOR);
 
@@ -4991,25 +5028,36 @@ void sev_init_vmcb(struct vcpu_svm *svm)
 	 */
 	clr_exception_intercept(svm, GP_VECTOR);
 
-	if (sev_es_guest(svm->vcpu.kvm))
-		sev_es_init_vmcb(svm);
+	if (init_event && sev_snp_guest(vcpu->kvm))
+		sev_snp_init_protected_guest_state(vcpu);
+
+	if (sev_es_guest(vcpu->kvm))
+		sev_es_init_vmcb(svm, init_event);
 }
 
-void sev_es_vcpu_reset(struct vcpu_svm *svm)
+int sev_vcpu_create(struct kvm_vcpu *vcpu)
 {
-	struct kvm_vcpu *vcpu = &svm->vcpu;
-	struct kvm_sev_info *sev = to_kvm_sev_info(vcpu->kvm);
+	struct vcpu_svm *svm = to_svm(vcpu);
+	struct page *vmsa_page;
+
+	mutex_init(&svm->sev_es.snp_vmsa_mutex);
+
+	if (!sev_es_guest(vcpu->kvm))
+		return 0;
 
 	/*
-	 * Set the GHCB MSR value as per the GHCB specification when emulating
-	 * vCPU RESET for an SEV-ES guest.
+	 * SEV-ES guests require a separate (from the VMCB) VMSA page used to
+	 * contain the encrypted register state of the guest.
 	 */
-	set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version,
-					    GHCB_VERSION_MIN,
-					    sev_enc_bit));
+	vmsa_page = snp_safe_alloc_page();
+	if (!vmsa_page)
+		return -ENOMEM;
 
-	mutex_init(&svm->sev_es.snp_vmsa_mutex);
-	svm->sev_es.hvdb_gpa = INVALID_PAGE;
+	svm->sev_es.vmsa = page_address(vmsa_page);
+
+	vcpu->arch.guest_tsc_protected = snp_is_secure_tsc_enabled(vcpu->kvm);
+
+	return 0;
 }
 
 void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_area *hostsa)

arch/x86/kvm/svm/svm.c

@@ -1086,7 +1086,7 @@ static void svm_recalc_intercepts_after_set_cpuid(struct kvm_vcpu *vcpu)
 	svm_recalc_msr_intercepts(vcpu);
 }
 
-static void init_vmcb(struct kvm_vcpu *vcpu)
+static void init_vmcb(struct kvm_vcpu *vcpu, bool init_event)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 	struct vmcb *vmcb = svm->vmcb01.ptr;
@@ -1224,7 +1224,7 @@ static void init_vmcb(struct kvm_vcpu *vcpu)
 		svm_set_intercept(svm, INTERCEPT_BUSLOCK);
 
 	if (sev_guest(vcpu->kvm))
-		sev_init_vmcb(svm);
+		sev_init_vmcb(svm, init_event);
 
 	svm_hv_init_vmcb(vmcb);
 
@@ -1247,9 +1247,6 @@ static void __svm_vcpu_reset(struct kvm_vcpu *vcpu)
 
 	svm->nmi_masked = false;
 	svm->awaiting_iret_completion = false;
-
-	if (sev_es_guest(vcpu->kvm))
-		sev_es_vcpu_reset(svm);
 }
 
 static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
@@ -1259,10 +1256,7 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
 	svm->spec_ctrl = 0;
 	svm->virt_spec_ctrl = 0;
 
-	if (init_event)
-		sev_snp_init_protected_guest_state(vcpu);
-
-	init_vmcb(vcpu);
+	init_vmcb(vcpu, init_event);
 
 	if (!init_event)
 		__svm_vcpu_reset(vcpu);
@@ -1278,7 +1272,6 @@ static int svm_vcpu_create(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm;
 	struct page *vmcb01_page;
-	struct page *vmsa_page = NULL;
 	int err;
 
 	BUILD_BUG_ON(offsetof(struct vcpu_svm, vcpu) != 0);
@@ -1292,26 +1285,21 @@ static int svm_vcpu_create(struct kvm_vcpu *vcpu)
 	if (sev_es_guest(vcpu->kvm)) {
 		struct kvm_sev_info *sev = to_kvm_sev_info(vcpu->kvm);
 
-		/*
-		 * SEV-ES guests require a separate VMSA page used to contain
-		 * the encrypted register state of the guest.
-		 */
-		vmsa_page = snp_safe_alloc_page();
-		if (!vmsa_page)
-			goto error_free_vmcb_page;
-
 		/* Sync VM SEV_FEATURES to VCPU - Might be overwritten later */
 		svm->sev_es.vmsa_features = sev->vmsa_features;
 	}
+	err = sev_vcpu_create(vcpu);
+	if(err)
+		goto error_free_vmcb_page;
 
 	err = avic_init_vcpu(svm);
 	if (err)
-		goto error_free_vmsa_page;
+		goto error_free_sev;
 
 	svm->msrpm = svm_vcpu_alloc_msrpm();
 	if (!svm->msrpm) {
 		err = -ENOMEM;
-		goto error_free_vmsa_page;
+		goto error_free_sev;
 	}
 
 	svm->x2avic_msrs_intercepted = true;
@@ -1320,16 +1308,12 @@ static int svm_vcpu_create(struct kvm_vcpu *vcpu)
 	svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT);
 	svm_switch_vmcb(svm, &svm->vmcb01);
 
-	if (vmsa_page)
-		svm->sev_es.vmsa = page_address(vmsa_page);
-
 	svm->guest_state_loaded = false;
 
 	return 0;
 
-error_free_vmsa_page:
-	if (vmsa_page)
-		__free_page(vmsa_page);
+error_free_sev:
+	sev_free_vcpu(vcpu);
 error_free_vmcb_page:
 	__free_page(vmcb01_page);
 out:

arch/x86/kvm/svm/svm.h

@@ -840,10 +840,9 @@ void avic_refresh_virtual_apic_mode(struct kvm_vcpu *vcpu);
 /* sev.c */
 
 int pre_sev_run(struct vcpu_svm *svm, int cpu);
-void sev_init_vmcb(struct vcpu_svm *svm);
+void sev_init_vmcb(struct vcpu_svm *svm, bool init_event);
 void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm);
 int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in);
-void sev_es_vcpu_reset(struct vcpu_svm *svm);
 void sev_es_recalc_msr_intercepts(struct kvm_vcpu *vcpu);
 void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector);
 void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_area *hostsa);
@@ -868,6 +867,7 @@ static inline struct page *snp_safe_alloc_page(void)
 	return snp_safe_alloc_page_node(numa_node_id(), GFP_KERNEL_ACCOUNT);
 }
 
+int sev_vcpu_create(struct kvm_vcpu *vcpu);
 void sev_free_vcpu(struct kvm_vcpu *vcpu);
 void sev_vm_destroy(struct kvm *kvm);
 void __init sev_set_cpu_caps(void);
@@ -877,7 +877,6 @@ int sev_cpu_init(struct svm_cpu_data *sd);
 int sev_dev_get_attr(u32 group, u64 attr, u64 *val);
 extern unsigned int max_sev_asid;
 void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code);
-void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu);
 int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order);
 void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end);
 int sev_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn);
@@ -906,6 +905,7 @@ static inline struct page *snp_safe_alloc_page(void)
 	return snp_safe_alloc_page_node(numa_node_id(), GFP_KERNEL_ACCOUNT);
 }
 
+static inline int sev_vcpu_create(struct kvm_vcpu *vcpu) { return 0; }
 static inline void sev_free_vcpu(struct kvm_vcpu *vcpu) {}
 static inline void sev_vm_destroy(struct kvm *kvm) {}
 static inline void __init sev_set_cpu_caps(void) {}
@@ -915,7 +915,6 @@ static inline int sev_cpu_init(struct svm_cpu_data *sd) { return 0; }
 static inline int sev_dev_get_attr(u32 group, u64 attr, u64 *val) { return -ENXIO; }
 #define max_sev_asid 0
 static inline void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code) {}
-static inline void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu) {}
 static inline int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order)
 {
 	return 0;