[PATCH v5 15/23] sev: add command to encrypt guest memory region

[Brijesh Singh <brijesh.singh@xxxxxxx>]

The KVM_SEV_LAUNCH_UPDATE_DATA command is used to encrypt a guest memory
region using the VM Encryption Key created using LAUNCH_START.

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
 accel/kvm/kvm-all.c  |  2 ++
 accel/kvm/sev.c      | 44 ++++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/sev.h |  1 +
 3 files changed, 47 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 54a0fd6097fb..d35eebb97901 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1675,6 +1675,8 @@ static int kvm_init(MachineState *ms)
         if (!kvm_state->memcrypt_handle) {
             goto err;
         }
+
+        kvm_state->memcrypt_encrypt_data = sev_encrypt_data;
     }
 
     ret = kvm_arch_init(ms, s);
diff --git a/accel/kvm/sev.c b/accel/kvm/sev.c
index 74eb67526bd0..83fc950bd3ac 100644
--- a/accel/kvm/sev.c
+++ b/accel/kvm/sev.c
@@ -368,6 +368,37 @@ sev_launch_start(SEVState *s)
     return 0;
 }
 
+static int
+sev_launch_update_data(uint8_t *addr, uint64_t len)
+{
+    int ret, fw_error;
+    struct kvm_sev_launch_update_data *update;
+
+    if (addr == NULL || len <= 0) {
+        return 1;
+    }
+
+    update = g_malloc0(sizeof(*update));
+    if (!update) {
+        return 1;
+    }
+
+    update->uaddr = (__u64)addr;
+    update->len = len;
+    ret = sev_ioctl(KVM_SEV_LAUNCH_UPDATE_DATA, update, &fw_error);
+    if (ret) {
+        error_report("%s: LAUNCH_UPDATE ret=%d fw_error=%d '%s'",
+                __func__, ret, fw_error, fw_error_to_str(fw_error));
+        goto err;
+    }
+
+    DPRINTF("SEV: LAUNCH_UPDATE_DATA %#lx+%#lx\n", (unsigned long)addr, len);
+
+err:
+    g_free(update);
+    return ret;
+}
+
 void *
 sev_guest_init(const char *id)
 {
@@ -417,6 +448,19 @@ err:
     return NULL;
 }
 
+int
+sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len)
+{
+    SEVState *s = (SEVState *)handle;
+
+    /* if SEV is in update state then encrypt the data else do nothing */
+    if (s->cur_state == SEV_STATE_LUPDATE) {
+        return sev_launch_update_data(ptr, len);
+    }
+
+    return 0;
+}
+
 static void
 sev_register_types(void)
 {
diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
index 45b464cc96f5..b1ea3f805290 100644
--- a/include/sysemu/sev.h
+++ b/include/sysemu/sev.h
@@ -69,6 +69,7 @@ struct SEVState {
 typedef struct SEVState SEVState;
 
 void *sev_guest_init(const char *id);
+int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len);
 
 #endif
 
-- 
2.9.5