[PATCH 1 of 4 V6] libxl: QMP stop/resume & refactor QEMU suspend/resume/save

[Shriram Rajagopalan <rshriram@cs.ubc.ca>]

# HG changeset patch
# User Shriram Rajagopalan <rshriram@cs.ubc.ca>
# Date 1337283418 25200
# Node ID 07d5f26fee0a65c8145bd1028568693e45cfd25c
# Parent  f8279258e3c96baccb8338a47af068bd650b121a
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>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff -r f8279258e3c9 -r 07d5f26fee0a tools/libxl/libxl_dom.c
--- a/tools/libxl/libxl_dom.c	Mon May 14 17:15:36 2012 +0100
+++ b/tools/libxl/libxl_dom.c	Thu May 17 12:36:58 2012 -0700
@@ -587,6 +587,54 @@
     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;
+    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;
+        /* Save DM state into filename */
+        ret = libxl__qmp_save(gc, domid, filename);
+        if (ret)
+            unlink(filename);
+        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");
+        libxl__wait_for_device_model(gc, domid, "running", NULL, NULL, NULL);
+        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;
@@ -616,7 +664,7 @@
             return 0;
         }
         si->guest_responded = 1;
-        return 1;
+        goto guest_suspended;
     }
 
     if (si->hvm && (!hvm_pvdrv || hvm_s_state)) {
@@ -694,7 +742,7 @@
             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 guest_suspended;
             }
         }
 
@@ -703,6 +751,17 @@
 
     LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "guest did not suspend");
     return 0;
+
+ guest_suspended:
+    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;
 }
 
 static inline char *save_helper(libxl__gc *gc, uint32_t domid,
@@ -885,23 +944,6 @@
     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:
-        ret = libxl__qmp_save(gc, domid, (char *)filename);
-        if (ret)
-            goto out;
-        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 f8279258e3c9 -r 07d5f26fee0a tools/libxl/libxl_internal.h
--- a/tools/libxl/libxl_internal.h	Mon May 14 17:15:36 2012 +0100
+++ b/tools/libxl/libxl_internal.h	Thu May 17 12:36:58 2012 -0700
@@ -759,6 +759,8 @@
                                          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);
 
@@ -1276,6 +1278,10 @@
 _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_save(libxl__gc *gc, int domid, const char *filename);
 /* close and free the QMP handler */
diff -r f8279258e3c9 -r 07d5f26fee0a tools/libxl/libxl_qmp.c
--- a/tools/libxl/libxl_qmp.c	Mon May 14 17:15:36 2012 +0100
+++ b/tools/libxl/libxl_qmp.c	Thu May 17 12:36:58 2012 -0700
@@ -883,6 +883,38 @@
     return rc;
 }
 
+int libxl__qmp_stop(libxl__gc *gc, int domid)
+{
+    libxl__qmp_handler *qmp = NULL;
+    int rc = 0;
+
+    qmp = libxl__qmp_initialize(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(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__gc *gc, uint32_t domid,
                                const libxl_domain_config *guest_config)
 {