[PATCH 3 of 6] libxl: QMP stop/resume & refactor QEMU suspend/resume/save

[rshriram@cs.ubc.ca]

# HG changeset patch
# User Shriram Rajagopalan <rshriram@cs.ubc.ca>
# Date 1327971511 28800
# Node ID cd3d43d88c0568142dd061e744c34479e1a440f4
# Parent  39f63438767a8225a3148a43139c10f55a62c669
libxl: QMP stop/resume & refactor QEMU suspend/resume/save

Implement QMP stop and resume functionality and split
device model save into 3 parts:
 suspend_dm(domid)
 save_dm(domid, fd)
 resume_dm(domid)

Integrate Device model suspend into suspend_common_callback

Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>

diff -r 39f63438767a -r cd3d43d88c05 tools/libxl/libxl_dom.c
--- a/tools/libxl/libxl_dom.c	Mon Jan 30 16:58:24 2012 -0800
+++ b/tools/libxl/libxl_dom.c	Mon Jan 30 16:58:31 2012 -0800
@@ -425,6 +425,61 @@ static int libxl__domain_suspend_common_
     return rc ? 0 : 1;
 }
 
+int libxl__domain_suspend_device_model(libxl__gc *gc, uint32_t domid)
+{
+    libxl_ctx *ctx = libxl__gc_owner(gc);
+    int ret = 0, fd2 = -1;
+    const char *filename = libxl__device_model_savefile(gc, domid);
+
+    switch (libxl__device_model_version_running(gc, domid)) {
+    case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL: {
+        LIBXL__LOG(ctx, LIBXL__LOG_DEBUG,
+                   "Saving device model state to %s", filename);
+        libxl__qemu_traditional_cmd(gc, domid, "save");
+        libxl__wait_for_device_model(gc, domid, "paused", NULL, NULL, NULL);
+        break;
+    }
+    case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
+        if (libxl__qmp_stop(gc, domid))
+            return ERROR_FAIL;
+        fd2 = open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
+        if (fd2 < 0) {
+            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
+                             "Unable to create a QEMU save file\n");
+            return ERROR_FAIL;
+        }
+        /* Save DM state into fd2 */
+        ret = libxl__qmp_migrate(gc, domid, fd2);
+        if (ret)
+            unlink(filename);
+        close(fd2);
+        fd2 = -1;
+        break;
+    default:
+        return ERROR_INVAL;
+    }
+
+    return ret;
+}
+
+int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid)
+{
+
+    switch (libxl__device_model_version_running(gc, domid)) {
+    case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL: {
+        libxl__qemu_traditional_cmd(gc, domid, "continue");
+        break;
+    }
+    case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
+        if (libxl__qmp_resume(gc, domid))
+            return ERROR_FAIL;
+    default:
+        return ERROR_INVAL;
+    }
+
+    return 0;
+}
+
 static int libxl__domain_suspend_common_callback(void *data)
 {
     struct suspendinfo *si = data;
@@ -454,7 +509,7 @@ static int libxl__domain_suspend_common_
             return 0;
         }
         si->guest_responded = 1;
-        return 1;
+        goto suspend_dm;
     }
 
     if (si->hvm && (!hvm_pvdrv || hvm_s_state)) {
@@ -532,7 +587,7 @@ static int libxl__domain_suspend_common_
             shutdown_reason = (info.flags >> XEN_DOMINF_shutdownshift) & XEN_DOMINF_shutdownmask;
             if (shutdown_reason == SHUTDOWN_suspend) {
                 LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "guest has suspended");
-                return 1;
+                goto suspend_dm;
             }
         }
 
@@ -541,6 +596,17 @@ static int libxl__domain_suspend_common_
 
     LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "guest did not suspend");
     return 0;
+
+ suspend_dm:
+    if (si->hvm) {
+        ret = libxl__domain_suspend_device_model(si->gc, si->domid);
+        if (ret) {
+            LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
+                       "libxl__domain_suspend_device_model failed ret=%d", ret);
+            return 0;
+        }
+    }
+    return 1;
 }
 
 int libxl__domain_suspend_common(libxl__gc *gc, uint32_t domid, int fd,
@@ -638,32 +704,6 @@ int libxl__domain_save_device_model(libx
     struct stat st;
     uint32_t qemu_state_len;
 
-    switch (libxl__device_model_version_running(gc, domid)) {
-    case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL: {
-        LIBXL__LOG(ctx, LIBXL__LOG_DEBUG,
-                   "Saving device model state to %s", filename);
-        libxl__qemu_traditional_cmd(gc, domid, "save");
-        libxl__wait_for_device_model(gc, domid, "paused", NULL, NULL, NULL);
-        break;
-    }
-    case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
-        fd2 = open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
-        if (fd2 < 0) {
-            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
-                             "Unable to create a QEMU save file\n");
-            return ERROR_FAIL;
-        }
-        /* Save DM state into fd2 */
-        ret = libxl__qmp_migrate(gc, domid, fd2);
-        if (ret)
-            goto out;
-        close(fd2);
-        fd2 = -1;
-        break;
-    default:
-        return ERROR_INVAL;
-    }
-
     if (stat(filename, &st) < 0)
     {
         LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Unable to stat qemu save file\n");
diff -r 39f63438767a -r cd3d43d88c05 tools/libxl/libxl_internal.h
--- a/tools/libxl/libxl_internal.h	Mon Jan 30 16:58:24 2012 -0800
+++ b/tools/libxl/libxl_internal.h	Mon Jan 30 16:58:31 2012 -0800
@@ -277,6 +277,8 @@ _hidden int libxl__domain_suspend_common
                                          libxl_domain_type type,
                                          int live, int debug);
 _hidden const char *libxl__device_model_savefile(libxl__gc *gc, uint32_t domid);
+_hidden int libxl__domain_suspend_device_model(libxl__gc *gc, uint32_t domid);
+_hidden int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid);
 _hidden int libxl__domain_save_device_model(libxl__gc *gc, uint32_t domid, int fd);
 _hidden void libxl__userdata_destroyall(libxl__gc *gc, uint32_t domid);
 
@@ -620,6 +622,10 @@ _hidden int libxl__qmp_query_serial(libx
 _hidden int libxl__qmp_pci_add(libxl__gc *gc, int d, libxl_device_pci *pcidev);
 _hidden int libxl__qmp_pci_del(libxl__gc *gc, int domid,
                                libxl_device_pci *pcidev);
+/* Suspend QEMU. */
+_hidden int libxl__qmp_stop(libxl__gc *gc, int domid);
+/* Resume QEMU. */
+_hidden int libxl__qmp_resume(libxl__gc *gc, int domid);
 /* Save current QEMU state into fd. */
 _hidden int libxl__qmp_migrate(libxl__gc *gc, int domid, int fd);
 /* close and free the QMP handler */
diff -r 39f63438767a -r cd3d43d88c05 tools/libxl/libxl_qmp.c
--- a/tools/libxl/libxl_qmp.c	Mon Jan 30 16:58:24 2012 -0800
+++ b/tools/libxl/libxl_qmp.c	Mon Jan 30 16:58:31 2012 -0800
@@ -878,6 +878,38 @@ out:
     return rc;
 }
 
+int libxl__qmp_stop(libxl__gc *gc, int domid)
+{
+    libxl__qmp_handler *qmp = NULL;
+    int rc = 0;
+
+    qmp = libxl__qmp_initialize(libxl__gc_owner(gc), domid);
+    if (!qmp)
+        return ERROR_FAIL;
+
+    rc = qmp_synchronous_send(qmp, "stop", NULL,
+                              NULL, NULL, qmp->timeout);
+
+    libxl__qmp_close(qmp);
+    return rc;
+}
+
+int libxl__qmp_resume(libxl__gc *gc, int domid)
+{
+    libxl__qmp_handler *qmp = NULL;
+    int rc = 0;
+
+    qmp = libxl__qmp_initialize(libxl__gc_owner(gc), domid);
+    if (!qmp)
+        return ERROR_FAIL;
+
+    rc = qmp_synchronous_send(qmp, "cont", NULL,
+                              NULL, NULL, qmp->timeout);
+
+    libxl__qmp_close(qmp);
+    return rc;
+}
+
 int libxl__qmp_initializations(libxl_ctx *ctx, uint32_t domid)
 {
     libxl__qmp_handler *qmp = NULL;