libxl: helper function to send commands to traditional qemu

Introduce a helper function to send commands to traditional
qemu. qemu_pci_add_xenstore, qemu_pci_remove_xenstore,
libxl__domain_save_device_model and libxl_domain_unpause have
been refactored to use this function.

Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>

4 files changed, 16 insertions, 10 deletions

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 6fcd319b58..68bba8f499 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -586,7 +586,7 @@ int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
         path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
         state = libxl__xs_read(gc, XBT_NULL, path);
         if (state != NULL && !strcmp(state, "paused")) {
-            libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "/local/domain/0/device-model/%d/command", domid), "continue");
+            libxl__qemu_traditional_cmd(gc, domid, "continue");
             libxl__wait_for_device_model(gc, domid, "running",
                                          NULL, NULL, NULL);
         }
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 692ee30288..efaa86192f 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -355,6 +355,15 @@ out:
     return rc;
 }
 
+int libxl__qemu_traditional_cmd(libxl__gc *gc, uint32_t domid,
+                                const char *cmd)
+{
+    char *path = NULL;
+    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/command",
+                          domid);
+    return libxl__xs_write(gc, XBT_NULL, path, "%s", cmd);
+}
+
 int libxl__domain_restore_common(libxl__gc *gc, uint32_t domid,
                                  libxl_domain_build_info *info,
                                  libxl__domain_build_state *state,
@@ -637,12 +646,9 @@ int libxl__domain_save_device_model(libxl__gc *gc, uint32_t domid, int fd)
 
     switch (libxl__device_model_version_running(gc, domid)) {
     case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL: {
-        char *path = NULL;
         LIBXL__LOG(ctx, LIBXL__LOG_DEBUG,
                    "Saving device model state to %s", filename);
-        path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/command",
-                              domid);
-        libxl__xs_write(gc, XBT_NULL, path, "save");
+        libxl__qemu_traditional_cmd(gc, domid, "save");
         libxl__wait_for_device_model(gc, domid, "paused", NULL, NULL, NULL);
         break;
     }
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 832cf35a9e..7629ca4082 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -617,6 +617,8 @@ _hidden int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
               libxl_domain_build_info *info,
               libxl__domain_build_state *state);
 
+_hidden int libxl__qemu_traditional_cmd(libxl__gc *gc, uint32_t domid,
+                                        const char *cmd);
 _hidden int libxl__domain_rename(libxl__gc *gc, uint32_t domid,
                                  const char *old_name, const char *new_name,
                                  xs_transaction_t trans);
diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c
index 99591c27ee..33425f5fe9 100644
--- a/tools/libxl/libxl_pci.c
+++ b/tools/libxl/libxl_pci.c
@@ -602,9 +602,8 @@ static int qemu_pci_add_xenstore(libxl__gc *gc, uint32_t domid,
         libxl__xs_write(gc, XBT_NULL, path, PCI_BDF, pcidev->domain,
                         pcidev->bus, pcidev->dev, pcidev->func);
     }
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/command",
-                          domid);
-    xs_write(ctx->xsh, XBT_NULL, path, "pci-ins", strlen("pci-ins"));
+
+    libxl__qemu_traditional_cmd(gc, domid, "pci-ins");
     rc = libxl__wait_for_device_model(gc, domid, NULL, NULL,
                                       pci_ins_check, state);
     path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/parameter",
@@ -857,12 +856,11 @@ static int qemu_pci_remove_xenstore(libxl__gc *gc, uint32_t domid,
     path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/parameter", domid);
     libxl__xs_write(gc, XBT_NULL, path, PCI_BDF, pcidev->domain,
                     pcidev->bus, pcidev->dev, pcidev->func);
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/command", domid);
 
     /* Remove all functions at once atomically by only signalling
      * device-model for function 0 */
     if ( !force && (pcidev->vdevfn & 0x7) == 0 ) {
-        xs_write(ctx->xsh, XBT_NULL, path, "pci-rem", strlen("pci-rem"));
+        libxl__qemu_traditional_cmd(gc, domid, "pci-rem");
         if (libxl__wait_for_device_model(gc, domid, "pci-removed",
                                          NULL, NULL, NULL) < 0) {
             LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Device Model didn't respond in time");