[Qemu-devel] [PATCH v3 07/14] target/i386: sev: provide callback to setup outgoing context

[Singh, Brijesh]

The user provides the target machine's Platform Diffie-Hellman key (PDH)
and certificate chain before starting the SEV guest migration. Cache the
certificate chain as we need them while creating the outgoing context.

Signed-off-by: Brijesh Singh <address@hidden>
---
 accel/kvm/kvm-all.c    | 12 +++++++++++
 accel/kvm/sev-stub.c   |  6 ++++++
 include/sysemu/sev.h   |  2 ++
 target/i386/sev.c      | 45 ++++++++++++++++++++++++++++++++++++++++++
 target/i386/sev_i386.h |  6 ++++++
 5 files changed, 71 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index f450f25295..d0304c6947 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -165,6 +165,17 @@ bool kvm_memcrypt_enabled(void)
     return false;
 }
 
+static int kvm_memcrypt_save_setup(const char *pdh, const char *plat_cert,
+                                   const char *amd_cert)
+{
+    return sev_save_setup(kvm_state->memcrypt_handle, pdh,
+                          plat_cert, amd_cert);
+}
+
+static struct MachineMemoryEncryptionOps sev_memory_encryption_ops = {
+    .save_setup = kvm_memcrypt_save_setup,
+};
+
 int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len)
 {
     if (kvm_state->memcrypt_handle &&
@@ -1968,6 +1979,7 @@ static int kvm_init(MachineState *ms)
         }
 
         kvm_state->memcrypt_encrypt_data = sev_encrypt_data;
+        mc->memory_encryption_ops = &sev_memory_encryption_ops;
     }
 
     ret = kvm_arch_init(ms, s);
diff --git a/accel/kvm/sev-stub.c b/accel/kvm/sev-stub.c
index 4f97452585..528f8cf7f1 100644
--- a/accel/kvm/sev-stub.c
+++ b/accel/kvm/sev-stub.c
@@ -24,3 +24,9 @@ void *sev_guest_init(const char *id)
 {
     return NULL;
 }
+
+int sev_save_setup(void *handle, const char *pdh, const char *plat_cert,
+                   const char *amd_cert)
+{
+    return 1;
+}
diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
index 98c1ec8d38..d5123d4fa3 100644
--- a/include/sysemu/sev.h
+++ b/include/sysemu/sev.h
@@ -18,4 +18,6 @@
 
 void *sev_guest_init(const char *id);
 int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len);
+int sev_save_setup(void *handle, const char *pdh, const char *plat_cert,
+                   const char *amd_cert);
 #endif
diff --git a/target/i386/sev.c b/target/i386/sev.c
index f1423cb0c0..70e9d86815 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -27,6 +27,7 @@
 #include "sysemu/sysemu.h"
 #include "trace.h"
 #include "migration/blocker.h"
+#include "migration/qemu-file.h"
 
 #define DEFAULT_GUEST_POLICY    0x1 /* disable debug */
 #define DEFAULT_SEV_DEVICE      "/dev/sev"
@@ -62,6 +63,8 @@ static const char *const sev_fw_errlist[] = {
 
 #define SEV_FW_MAX_ERROR      ARRAY_SIZE(sev_fw_errlist)
 
+#define SEV_FW_BLOB_MAX_SIZE            0x4000          /* 16KB */
+
 static int
 sev_ioctl(int fd, int cmd, void *data, int *error)
 {
@@ -729,6 +732,48 @@ sev_vm_state_change(void *opaque, int running, RunState 
state)
     }
 }
 
+static inline bool check_blob_length(size_t value)
+{
+    if (value > SEV_FW_BLOB_MAX_SIZE) {
+        error_report("invalid length max=%ld got=%d",
+                     value, SEV_FW_BLOB_MAX_SIZE);
+        return false;
+    }
+
+    return true;
+}
+
+int sev_save_setup(void *handle, const char *pdh, const char *plat_cert,
+                   const char *amd_cert)
+{
+    SEVState *s = (SEVState *)handle;
+
+    s->remote_pdh = g_base64_decode(pdh, &s->remote_pdh_len);
+    if (!check_blob_length(s->remote_pdh_len)) {
+        goto error;
+    }
+
+    s->remote_plat_cert = g_base64_decode(plat_cert,
+                                          &s->remote_plat_cert_len);
+    if (!check_blob_length(s->remote_plat_cert_len)) {
+        goto error;
+    }
+
+    s->amd_cert = g_base64_decode(amd_cert, &s->amd_cert_len);
+    if (!check_blob_length(s->amd_cert_len)) {
+        goto error;
+    }
+
+    return 0;
+
+error:
+    g_free(s->remote_pdh);
+    g_free(s->remote_plat_cert);
+    g_free(s->amd_cert);
+
+    return 1;
+}
+
 void *
 sev_guest_init(const char *id)
 {
diff --git a/target/i386/sev_i386.h b/target/i386/sev_i386.h
index 55313441ae..32906de998 100644
--- a/target/i386/sev_i386.h
+++ b/target/i386/sev_i386.h
@@ -81,6 +81,12 @@ struct SEVState {
     int sev_fd;
     SevState state;
     gchar *measurement;
+    guchar *remote_pdh;
+    size_t remote_pdh_len;
+    guchar *remote_plat_cert;
+    size_t remote_plat_cert_len;
+    guchar *amd_cert;
+    size_t amd_cert_len;
 };
 
 typedef struct SEVState SEVState;
-- 
2.17.1