[PATCH v6 1/6] sev/i386: Add initial support for SEV-ES

[Tom Lendacky <thomas.lendacky@xxxxxxx>]

From: Tom Lendacky <thomas.lendacky@xxxxxxx>

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@xxxxxxxxxx>
Cc: Richard Henderson <richard.henderson@xxxxxxxxxx>
Cc: Eduardo Habkost <ehabkost@xxxxxxxxxx>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@xxxxxxxxxx>
Co-developed-by: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
 target/i386/cpu.c      |  1 +
 target/i386/sev-stub.c |  6 ++++++
 target/i386/sev.c      | 44 ++++++++++++++++++++++++++++++++++++++++--
 target/i386/sev_i386.h |  1 +
 4 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 72a79e6019..0415d8a99c 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5987,6 +5987,7 @@ 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;
diff --git a/target/i386/sev-stub.c b/target/i386/sev-stub.c
index c1fecc2101..229a2ee77b 100644
--- a/target/i386/sev-stub.c
+++ b/target/i386/sev-stub.c
@@ -49,8 +49,14 @@ 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)
 {
     return 1;
 }
+
+bool sev_es_enabled(void)
+{
+    return false;
+}
diff --git a/target/i386/sev.c b/target/i386/sev.c
index 1546606811..fce2128c07 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -360,6 +360,12 @@ sev_enabled(void)
     return !!sev_guest;
 }
 
+bool
+sev_es_enabled(void)
+{
+    return false;
+}
+
 uint64_t
 sev_get_me_mask(void)
 {
@@ -580,6 +586,20 @@ 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)
 {
@@ -592,6 +612,14 @@ 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 */
@@ -686,7 +714,7 @@ sev_guest_init(const char *id)
 {
     SevGuestState *sev;
     char *devname;
-    int ret, fw_error;
+    int ret, fw_error, cmd;
     uint32_t ebx;
     uint32_t host_cbitpos;
     struct sev_user_data_status status = {};
@@ -747,8 +775,20 @@ sev_guest_init(const char *id)
     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_report("%s: failed to initialize ret=%d fw_error=%d '%s'",
                      __func__, ret, fw_error, fw_error_to_str(fw_error));
diff --git a/target/i386/sev_i386.h b/target/i386/sev_i386.h
index 4db6960f60..4f9a5e9b21 100644
--- a/target/i386/sev_i386.h
+++ b/target/i386/sev_i386.h
@@ -29,6 +29,7 @@
 #define SEV_POLICY_SEV          0x20
 
 extern bool sev_enabled(void);
+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);
-- 
2.30.0