qemu: Implement the driver backend for virDomainGetLaunchSecurityInfo

This patch implements the internal driver API for launch event into
qemu driver. When SEV is enabled, execute 'query-sev-launch-measurement'
to get the measurement of memory encrypted through launch sequence.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>

src/qemu/qemu_driver.c

@@ -21501,6 +21501,74 @@ qemuNodeGetSEVInfo(virConnectPtr conn,
 }
 
 
+static int
+qemuDomainGetSEVMeasurement(virQEMUDriverPtr driver,
+                            virDomainObjPtr vm,
+                            virTypedParameterPtr *params,
+                            int *nparams,
+                            unsigned int flags)
+{
+    int ret = -1;
+    char *tmp;
+    int maxpar = 0;
+
+    virCheckFlags(VIR_TYPED_PARAM_STRING_OKAY, -1);
+
+    if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_QUERY) < 0)
+        return -1;
+
+    if (qemuDomainObjEnterMonitorAsync(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)
+        goto endjob;
+
+    tmp = qemuMonitorGetSEVMeasurement(QEMU_DOMAIN_PRIVATE(vm)->mon);
+    if (tmp == NULL)
+        goto endjob;
+
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        goto endjob;
+
+    if (virTypedParamsAddString(params, nparams, &maxpar,
+                                VIR_DOMAIN_LAUNCH_SECURITY_SEV_MEASUREMENT,
+                                tmp) < 0)
+        goto endjob;
+
+    VIR_FREE(tmp);
+    ret = 0;
+
+ endjob:
+    qemuDomainObjEndJob(driver, vm);
+    return ret;
+}
+
+
+static int
+qemuDomainGetLaunchSecurityInfo(virDomainPtr domain,
+                                virTypedParameterPtr *params,
+                                int *nparams,
+                                unsigned int flags)
+{
+    virQEMUDriverPtr driver = domain->conn->privateData;
+    virDomainObjPtr vm;
+    int ret = -1;
+
+    if (!(vm = qemuDomObjFromDomain(domain)))
+        goto cleanup;
+
+    if (virDomainGetLaunchSecurityInfoEnsureACL(domain->conn, vm->def) < 0)
+        goto cleanup;
+
+    if (vm->def->sev) {
+        if (qemuDomainGetSEVMeasurement(driver, vm, params, nparams, flags) < 0)
+            goto cleanup;
+    }
+
+    ret = 0;
+
+ cleanup:
+    virDomainObjEndAPI(&vm);
+    return ret;
+}
+
 static virHypervisorDriver qemuHypervisorDriver = {
     .name = QEMU_DRIVER_NAME,
     .connectURIProbe = qemuConnectURIProbe,
@@ -21725,6 +21793,7 @@ static virHypervisorDriver qemuHypervisorDriver = {
     .connectCompareHypervisorCPU = qemuConnectCompareHypervisorCPU, /* 4.4.0 */
     .connectBaselineHypervisorCPU = qemuConnectBaselineHypervisorCPU, /* 4.4.0 */
     .nodeGetSEVInfo = qemuNodeGetSEVInfo, /* 4.5.0 */
+    .domainGetLaunchSecurityInfo = qemuDomainGetLaunchSecurityInfo, /* 4.5.0 */
 };
 
 

src/qemu/qemu_monitor.c

@@ -4297,3 +4297,11 @@ qemuMonitorBlockdevDel(qemuMonitorPtr mon,
 
     return qemuMonitorJSONBlockdevDel(mon, nodename);
 }
+
+char *
+qemuMonitorGetSEVMeasurement(qemuMonitorPtr mon)
+{
+    QEMU_CHECK_MONITOR_NULL(mon);
+
+    return qemuMonitorJSONGetSEVMeasurement(mon);
+}

src/qemu/qemu_monitor.h

@@ -1142,4 +1142,7 @@ int qemuMonitorBlockdevAdd(qemuMonitorPtr mon,
 int qemuMonitorBlockdevDel(qemuMonitorPtr mon,
                            const char *nodename);
 
+char *
+qemuMonitorGetSEVMeasurement(qemuMonitorPtr mon);
+
 #endif /* QEMU_MONITOR_H */

src/qemu/qemu_monitor_json.c

@@ -7994,3 +7994,45 @@ qemuMonitorJSONBlockdevDel(qemuMonitorPtr mon,
     virJSONValueFree(reply);
     return ret;
 }
+
+/**
+ * The function is used to retrieve the measurement of a SEV guest.
+ * The measurement is signature of the memory contents that was encrypted
+ * through the SEV launch flow.
+ *
+ * A example JSON output:
+ *
+ * { "execute" : "query-sev-launch-measure" }
+ * { "return" : { "data" : "4l8LXeNlSPUDlXPJG5966/8%YZ" } }
+ */
+char *
+qemuMonitorJSONGetSEVMeasurement(qemuMonitorPtr mon)
+{
+    const char *tmp;
+    char *measurement = NULL;
+    virJSONValuePtr cmd;
+    virJSONValuePtr reply = NULL;
+    virJSONValuePtr data;
+
+    if (!(cmd = qemuMonitorJSONMakeCommand("query-sev-launch-measure", NULL)))
+         return NULL;
+
+    if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
+        goto cleanup;
+
+    if (qemuMonitorJSONCheckReply(cmd, reply, VIR_JSON_TYPE_OBJECT) < 0)
+        goto cleanup;
+
+    data = virJSONValueObjectGetObject(reply, "return");
+
+    if (!(tmp = virJSONValueObjectGetString(data, "data")))
+        goto cleanup;
+
+    if (VIR_STRDUP(measurement, tmp) < 0)
+        goto cleanup;
+
+ cleanup:
+    virJSONValueFree(cmd);
+    virJSONValueFree(reply);
+    return measurement;
+}

src/qemu/qemu_monitor_json.h

@@ -343,6 +343,8 @@ int qemuMonitorJSONGetBlockIoThrottle(qemuMonitorPtr mon,
 
 int qemuMonitorJSONSystemWakeup(qemuMonitorPtr mon);
 
+char *qemuMonitorJSONGetSEVMeasurement(qemuMonitorPtr mon);
+
 int qemuMonitorJSONGetVersion(qemuMonitorPtr mon,
                               int *major,
                               int *minor,