sev/i386: Add initial support for SEV-ES

Provide initial support for SEV-ES. This includes creating a function to
indicate the guest is an SEV-ES guest (which will return false until all
support is in place), performing the proper SEV initialization and
ensuring that the guest CPU state is measured as part of the launch.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Co-developed-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com>
Message-Id: <2e6386cbc1ddeaf701547dd5677adf5ddab2b6bd.1611682609.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/cpu.c

@@ -5984,6 +5984,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
         break;
     case 0x8000001F:
         *eax = sev_enabled() ? 0x2 : 0;
+        *eax |= sev_es_enabled() ? 0x8 : 0;
         *ebx = sev_get_cbit_position();
         *ebx |= sev_get_reduced_phys_bits() << 6;
         *ecx = 0;

target/i386/sev-stub.c

@@ -49,6 +49,7 @@ SevCapability *sev_get_capabilities(Error **errp)
     error_setg(errp, "SEV is not available in this QEMU");
     return NULL;
 }
+
 int sev_inject_launch_secret(const char *hdr, const char *secret,
                              uint64_t gpa, Error **errp)
 {
@@ -59,3 +60,8 @@ int sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp)
 {
     return 0;
 }
+
+bool sev_es_enabled(void)
+{
+    return false;
+}

target/i386/sev.c

@@ -341,6 +341,12 @@ sev_enabled(void)
     return !!sev_guest;
 }
 
+bool
+sev_es_enabled(void)
+{
+    return false;
+}
+
 uint64_t
 sev_get_me_mask(void)
 {
@@ -561,6 +567,20 @@ sev_launch_update_data(SevGuestState *sev, uint8_t *addr, uint64_t len)
     return ret;
 }
 
+static int
+sev_launch_update_vmsa(SevGuestState *sev)
+{
+    int ret, fw_error;
+
+    ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_UPDATE_VMSA, NULL, &fw_error);
+    if (ret) {
+        error_report("%s: LAUNCH_UPDATE_VMSA ret=%d fw_error=%d '%s'",
+                __func__, ret, fw_error, fw_error_to_str(fw_error));
+    }
+
+    return ret;
+}
+
 static void
 sev_launch_get_measure(Notifier *notifier, void *unused)
 {
@@ -573,6 +593,14 @@ sev_launch_get_measure(Notifier *notifier, void *unused)
         return;
     }
 
+    if (sev_es_enabled()) {
+        /* measure all the VM save areas before getting launch_measure */
+        ret = sev_launch_update_vmsa(sev);
+        if (ret) {
+            exit(1);
+        }
+    }
+
     measurement = g_new0(struct kvm_sev_launch_measure, 1);
 
     /* query the measurement blob length */
@@ -667,7 +695,7 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     SevGuestState *sev
         = (SevGuestState *)object_dynamic_cast(OBJECT(cgs), TYPE_SEV_GUEST);
     char *devname;
-    int ret, fw_error;
+    int ret, fw_error, cmd;
     uint32_t ebx;
     uint32_t host_cbitpos;
     struct sev_user_data_status status = {};
@@ -724,8 +752,20 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
     sev->api_major = status.api_major;
     sev->api_minor = status.api_minor;
 
+    if (sev_es_enabled()) {
+        if (!(status.flags & SEV_STATUS_FLAGS_CONFIG_ES)) {
+            error_report("%s: guest policy requires SEV-ES, but "
+                         "host SEV-ES support unavailable",
+                         __func__);
+            goto err;
+        }
+        cmd = KVM_SEV_ES_INIT;
+    } else {
+        cmd = KVM_SEV_INIT;
+    }
+
     trace_kvm_sev_init();
-    ret = sev_ioctl(sev->sev_fd, KVM_SEV_INIT, NULL, &fw_error);
+    ret = sev_ioctl(sev->sev_fd, cmd, NULL, &fw_error);
     if (ret) {
         error_setg(errp, "%s: failed to initialize ret=%d fw_error=%d '%s'",
                    __func__, ret, fw_error, fw_error_to_str(fw_error));

target/i386/sev_i386.h

@@ -28,6 +28,7 @@
 #define SEV_POLICY_DOMAIN       0x10
 #define SEV_POLICY_SEV          0x20
 
+extern bool sev_es_enabled(void);
 extern uint64_t sev_get_me_mask(void);
 extern SevInfo *sev_get_info(void);
 extern uint32_t sev_get_cbit_position(void);