KVM: SVM: Add support for SEV-ES capability in KVM

Add support to KVM for determining if a system is capable of supporting
SEV-ES as well as determining if a guest is an SEV-ES guest.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <e66792323982c822350e40c7a1cf67ea2978a70b.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/Kconfig

@@ -100,7 +100,8 @@ config KVM_AMD_SEV
 	depends on KVM_AMD && X86_64
 	depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m)
 	help
-	Provides support for launching Encrypted VMs on AMD processors.
+	  Provides support for launching Encrypted VMs (SEV) and Encrypted VMs
+	  with Encrypted State (SEV-ES) on AMD processors.
 
 config KVM_MMU_AUDIT
 	bool "Audit KVM MMU"

arch/x86/kvm/svm/sev.c

@@ -932,7 +932,7 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 	struct kvm_sev_cmd sev_cmd;
 	int r;
 
-	if (!svm_sev_enabled())
+	if (!svm_sev_enabled() || !sev)
 		return -ENOTTY;
 
 	if (!argp)
@@ -1125,29 +1125,58 @@ void sev_vm_destroy(struct kvm *kvm)
 	sev_asid_free(sev->asid);
 }
 
-int __init sev_hardware_setup(void)
+void __init sev_hardware_setup(void)
 {
+	unsigned int eax, ebx, ecx, edx;
+	bool sev_es_supported = false;
+	bool sev_supported = false;
+
+	/* Does the CPU support SEV? */
+	if (!boot_cpu_has(X86_FEATURE_SEV))
+		goto out;
+
+	/* Retrieve SEV CPUID information */
+	cpuid(0x8000001f, &eax, &ebx, &ecx, &edx);
+
 	/* Maximum number of encrypted guests supported simultaneously */
-	max_sev_asid = cpuid_ecx(0x8000001F);
+	max_sev_asid = ecx;
 
 	if (!svm_sev_enabled())
-		return 1;
+		goto out;
 
 	/* Minimum ASID value that should be used for SEV guest */
-	min_sev_asid = cpuid_edx(0x8000001F);
+	min_sev_asid = edx;
 
 	/* Initialize SEV ASID bitmaps */
 	sev_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
 	if (!sev_asid_bitmap)
-		return 1;
+		goto out;
 
 	sev_reclaim_asid_bitmap = bitmap_zalloc(max_sev_asid, GFP_KERNEL);
 	if (!sev_reclaim_asid_bitmap)
-		return 1;
+		goto out;
 
-	pr_info("SEV supported\n");
+	pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1);
+	sev_supported = true;
 
-	return 0;
+	/* SEV-ES support requested? */
+	if (!sev_es)
+		goto out;
+
+	/* Does the CPU support SEV-ES? */
+	if (!boot_cpu_has(X86_FEATURE_SEV_ES))
+		goto out;
+
+	/* Has the system been allocated ASIDs for SEV-ES? */
+	if (min_sev_asid == 1)
+		goto out;
+
+	pr_info("SEV-ES supported: %u ASIDs\n", min_sev_asid - 1);
+	sev_es_supported = true;
+
+out:
+	sev = sev_supported;
+	sev_es = sev_es_supported;
 }
 
 void sev_hardware_teardown(void)

arch/x86/kvm/svm/svm.c

@@ -186,9 +186,13 @@ static int vgif = true;
 module_param(vgif, int, 0444);
 
 /* enable/disable SEV support */
-static int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
 module_param(sev, int, 0444);
 
+/* enable/disable SEV-ES support */
+int sev_es = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+module_param(sev_es, int, 0444);
+
 static bool __read_mostly dump_invalid_vmcb = 0;
 module_param(dump_invalid_vmcb, bool, 0644);
 
@@ -958,15 +962,11 @@ static __init int svm_hardware_setup(void)
 		kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
 	}
 
-	if (sev) {
-		if (boot_cpu_has(X86_FEATURE_SEV) &&
-		    IS_ENABLED(CONFIG_KVM_AMD_SEV)) {
-			r = sev_hardware_setup();
-			if (r)
-				sev = false;
+	if (IS_ENABLED(CONFIG_KVM_AMD_SEV) && sev) {
+		sev_hardware_setup();
 	} else {
 		sev = false;
-		}
+		sev_es = false;
 	}
 
 	svm_adjust_mmio_mask();

arch/x86/kvm/svm/svm.h

@@ -61,6 +61,7 @@ enum {
 
 struct kvm_sev_info {
 	bool active;		/* SEV enabled guest */
+	bool es_active;		/* SEV-ES enabled guest */
 	unsigned int asid;	/* ASID used for this guest */
 	unsigned int handle;	/* SEV firmware handle */
 	int fd;			/* SEV device fd */
@@ -194,6 +195,28 @@ static inline struct kvm_svm *to_kvm_svm(struct kvm *kvm)
 	return container_of(kvm, struct kvm_svm, kvm);
 }
 
+static inline bool sev_guest(struct kvm *kvm)
+{
+#ifdef CONFIG_KVM_AMD_SEV
+	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+
+	return sev->active;
+#else
+	return false;
+#endif
+}
+
+static inline bool sev_es_guest(struct kvm *kvm)
+{
+#ifdef CONFIG_KVM_AMD_SEV
+	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+
+	return sev_guest(kvm) && sev->es_active;
+#else
+	return false;
+#endif
+}
+
 static inline void vmcb_mark_all_dirty(struct vmcb *vmcb)
 {
 	vmcb->control.clean = 0;
@@ -352,6 +375,9 @@ static inline bool gif_set(struct vcpu_svm *svm)
 #define MSR_CR3_LONG_MBZ_MASK			0xfff0000000000000U
 #define MSR_INVALID				0xffffffffU
 
+extern int sev;
+extern int sev_es;
+
 u32 svm_msrpm_offset(u32 msr);
 u32 *svm_vcpu_alloc_msrpm(void);
 void svm_vcpu_init_msrpm(struct kvm_vcpu *vcpu, u32 *msrpm);
@@ -473,17 +499,6 @@ void svm_vcpu_unblocking(struct kvm_vcpu *vcpu);
 
 extern unsigned int max_sev_asid;
 
-static inline bool sev_guest(struct kvm *kvm)
-{
-#ifdef CONFIG_KVM_AMD_SEV
-	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
-
-	return sev->active;
-#else
-	return false;
-#endif
-}
-
 static inline bool svm_sev_enabled(void)
 {
 	return IS_ENABLED(CONFIG_KVM_AMD_SEV) ? max_sev_asid : 0;
@@ -496,7 +511,7 @@ int svm_register_enc_region(struct kvm *kvm,
 int svm_unregister_enc_region(struct kvm *kvm,
 			      struct kvm_enc_region *range);
 void pre_sev_run(struct vcpu_svm *svm, int cpu);
-int __init sev_hardware_setup(void);
+void __init sev_hardware_setup(void);
 void sev_hardware_teardown(void);
 
 #endif