[Qemu-devel] [RFC PATCH v1 08/22] sev: add SEV launch update command

[Brijesh Singh]

The SEV LAUNCH_UPDATE command is used to encrypt the guest memory region.

For more information see [1], section 6.2

[1] http://support.amd.com/TechDocs/55766_SEV-KM%20API_Spec.pdf

The following KVM RFC patches defines and implements this command

http://marc.info/?l=kvm&m=147190852423972&w=2
http://marc.info/?l=kvm&m=147190859023996&w=2

Signed-off-by: Brijesh Singh <address@hidden>
---
 include/sysemu/sev.h |    9 +++++++++
 sev.c                |   36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
index b8a7afa..b58a9d7 100644
--- a/include/sysemu/sev.h
+++ b/include/sysemu/sev.h
@@ -30,5 +30,14 @@ int sev_init(KVMState *kvm_state);
  */
 int kvm_sev_guest_start(void);
 
+/**
+ * kvm_sev_guest_update - encrypt the memory region.
+ * @address: host virtual address of memory region (must be 16-byte aligned)
+ * @len: length of memory region (must be 16-byte aligned).
+ *
+ * Returns: 0 on success, or 1 on failure.
+ */
+int kvm_sev_guest_update(uint8_t *address, uint32_t len);
+
 #endif
 
diff --git a/sev.c b/sev.c
index 40a126a..a451dc0 100644
--- a/sev.c
+++ b/sev.c
@@ -304,6 +304,28 @@ static int sev_launch_start(void)
     return 0;
 }
 
+static int sev_launch_update(uint8_t *addr, uint32_t len)
+{
+    int ret;
+    SEVInfo *s = sev_info;
+    struct kvm_sev_issue_cmd input;
+    struct kvm_sev_launch_update *update = s->launch_update;
+
+    update->address = (uint64_t) addr;
+    update->length = len;
+    input.cmd = KVM_SEV_LAUNCH_UPDATE;
+    input.opaque = (unsigned long)update;
+    ret = kvm_vm_ioctl(kvm_state, KVM_SEV_ISSUE_CMD, &input);
+    if (ret) {
+        fprintf(stderr, "SEV: launch_update failed ret=%d (%#010x)\n",
+                ret, input.ret_code);
+        exit(EXIT_FAILURE);
+    }
+
+    DPRINTF("SEV: LAUNCH update [%#lx+0x%x]\n", (uint64_t)addr, len);
+    return 0;
+}
+
 int kvm_sev_guest_start(void)
 {
     SEVInfo *s = sev_info;
@@ -335,3 +357,17 @@ int kvm_sev_guest_start(void)
     return 1;
 }
 
+int kvm_sev_guest_update(uint8_t *addr, uint32_t len)
+{
+    SEVInfo *s = sev_info;
+
+    if (!s) {
+        return 1;
+    }
+
+    if (s->state == SEV_LAUNCH_START) {
+        return sev_launch_update(addr, len);
+    }
+
+    return 1;
+}