[Qemu-devel] [PATCH v6 15/23] sev: add command to encrypt guest memory region

[Brijesh Singh <brijesh.singh@amd.com>]

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@amd.com>
---
 accel/kvm/kvm-all.c    |  2 ++
 accel/kvm/sev.c        | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 accel/kvm/trace-events |  1 +
 include/sysemu/sev.h   |  1 +
 4 files changed, 53 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 eea07ac9642f..1f757df725df 100644
--- a/accel/kvm/sev.c
+++ b/accel/kvm/sev.c
@@ -95,6 +95,12 @@ fw_error_to_str(int code)
     return sev_fw_errlist[code];
 }
 
+static bool
+sev_check_state(SevGuestState state)
+{
+    return current_sev_guest_state == state ? true : false;
+}
+
 static void
 sev_set_guest_state(SevGuestState new_state)
 {
@@ -382,6 +388,36 @@ 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;
+    trace_kvm_sev_launch_update_data(addr, 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;
+    }
+
+err:
+    g_free(update);
+    return ret;
+}
+
 void *
 sev_guest_init(const char *id)
 {
@@ -432,6 +468,19 @@ err:
     return NULL;
 }
 
+int
+sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len)
+{
+    assert (handle);
+
+    /* if SEV is in update state then encrypt the data else do nothing */
+    if (sev_check_state(SEV_STATE_LUPDATE)) {
+        return sev_launch_update_data(ptr, len);
+    }
+
+    return 0;
+}
+
 static void
 sev_register_types(void)
 {
diff --git a/accel/kvm/trace-events b/accel/kvm/trace-events
index a4ea1c382ec2..c55546f36a25 100644
--- a/accel/kvm/trace-events
+++ b/accel/kvm/trace-events
@@ -19,3 +19,4 @@ kvm_memcrypt_register_region(void *addr, size_t len) "addr %p len 0x%lu"
 kvm_memcrypt_unregister_region(void *addr, size_t len) "addr %p len 0x%lu"
 kvm_sev_change_state(char *old, char *new) "%s -> %s"
 kvm_sev_launch_start(int policy, void *session, void *pdh) "policy 0x%x session %p pdh %p"
+kvm_sev_launch_update_data(void *addr, uint64_t len) "addr %p len 0x%" PRIu64
diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
index 392b21fafbd3..839800efdbbf 100644
--- a/include/sysemu/sev.h
+++ b/include/sysemu/sev.h
@@ -68,6 +68,7 @@ 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