libxl: use new QEMU xenstore protocol

Originally both QEMU traditional and QEMU upstream used hardcoded
/local/domain/0 paths. This patch changes the protocol to use
/local/domain/$dm_domid path.

For QEMU traditional and upstream without stubdom, $dm_domid is 0 so
the path is in fact still /local/domain/0.

For QEMU traditional stubdom, this is incompatible protocol change.
However QEMU traditional is shipped with Xen so we are allowed to do
such change. This change needs to work with corresponding QEMU
traditional changeset.

There is no compatibility issue with QEMU upstream stubdom, because QEMU
upstream stubdom doesn't exist yet.

Watch /local/domain/$dm_domid/device-model/$domid/state, wait until
state turns "running" then unpause guest.

LIBXL_STUBDOM_START_TIMEOUT is the timeout used wait for stubdom to be
ready. My test on a very old machine (Core 2 6400) showed that it might
need more than 20s before the stubdom is ready to serve DomU.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index e9b4ed3191a24a2a62716aa386f1e87ec9e4f45a..4026641f07e98ee3aa3b9563ecd36fc345d69397 100644 (file)
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -1033,7 +1033,9 @@ int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
     }
 
     if (type == LIBXL_DOMAIN_TYPE_HVM) {
-        path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
+        uint32_t dm_domid = libxl_get_stubdom_id(ctx, domid);
+
+        path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
         state = libxl__xs_read(gc, XBT_NULL, path);
         if (state != NULL && !strcmp(state, "paused")) {
             libxl__qemu_traditional_cmd(gc, domid, "continue");

diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
index 0f50d0475d2e3604f2c9e960d315e19ac9cbfde7..0c06dc4bd494cfe49e71ec59e0ff3846313c596b 100644 (file)
--- a/tools/libxl/libxl_device.c
+++ b/tools/libxl/libxl_device.c
@@ -1188,7 +1188,9 @@ int libxl__wait_for_device_model_deprecated(libxl__gc *gc,
                                  void *check_callback_userdata)
 {
     char *path;
-    path = GCSPRINTF("/local/domain/0/device-model/%d/state", domid);
+    uint32_t dm_domid = libxl_get_stubdom_id(CTX, domid);
+
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
     return libxl__xenstore_child_wait_deprecated(gc, domid,
                                      LIBXL_DEVICE_MODEL_START_TIMEOUT,
                                      "Device Model", path, state, spawning,

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index af8b8d33dafd8b950b7d92c01e8cd4d50470a814..d5fd610d9bd1e6cc34b260dc7f42db0b624be6ab 100644 (file)
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -1001,6 +1001,8 @@ static void stubdom_pvqemu_cb(libxl__egc *egc,
 static void spawn_stubdom_pvqemu_destroy_cb(libxl__egc *egc,
                                             libxl__destroy_domid_state *dis,
                                             int rc);
+static void stubdom_xswait_cb(libxl__egc *egc, libxl__xswait_state *xswait,
+                              int rc, const char *p);
 
 char *libxl__stub_dm_name(libxl__gc *gc, const char *guest_name)
 {
@@ -1130,9 +1132,10 @@ void libxl__spawn_stub_dm(libxl__egc *egc, libxl__stub_dm_spawn_state *sdss)
 retry_transaction:
     t = xs_transaction_start(ctx->xsh);
     xs_mkdir(ctx->xsh, t,
-        libxl__sprintf(gc, "/local/domain/0/device-model/%d", guest_domid));
+             libxl__device_model_xs_path(gc, dm_domid, guest_domid, ""));
     xs_set_permissions(ctx->xsh, t,
-        libxl__sprintf(gc, "/local/domain/0/device-model/%d", guest_domid),
+                       libxl__device_model_xs_path(gc, dm_domid,
+                                                   guest_domid, ""),
                        perm, ARRAY_SIZE(perm));
     if (!xs_transaction_end(ctx->xsh, t, 0))
         if (errno == EAGAIN)
@@ -1278,6 +1281,8 @@ static void stubdom_pvqemu_cb(libxl__egc *egc,
     STATE_AO_GC(sdss->dm.spawn.ao);
     uint32_t dm_domid = sdss->pvqemu.guest_domid;
 
+    libxl__xswait_init(&sdss->xswait);
+
     if (rc) {
         LOGE(ERROR, "error connecting nics devices");
         goto out;
@@ -1286,10 +1291,45 @@ static void stubdom_pvqemu_cb(libxl__egc *egc,
     rc = libxl_domain_unpause(CTX, dm_domid);
     if (rc) goto out;
 
+    sdss->xswait.ao = ao;
+    sdss->xswait.what = GCSPRINTF("Stubdom %u for %u startup",
+                                  dm_domid, sdss->dm.guest_domid);
+    sdss->xswait.path =
+        libxl__device_model_xs_path(gc, dm_domid, sdss->dm.guest_domid,
+                                    "/state");
+    sdss->xswait.timeout_ms = LIBXL_STUBDOM_START_TIMEOUT * 1000;
+    sdss->xswait.callback = stubdom_xswait_cb;
+    rc = libxl__xswait_start(gc, &sdss->xswait);
+    if (rc) goto out;
+
+    return;
+
+ out:
+    stubdom_xswait_cb(egc, &sdss->xswait, rc, NULL);
+}
+
+static void stubdom_xswait_cb(libxl__egc *egc, libxl__xswait_state *xswait,
+                              int rc, const char *p)
+{
+    EGC_GC;
+    libxl__stub_dm_spawn_state *sdss = CONTAINER_OF(xswait, *sdss, xswait);
+    uint32_t dm_domid = sdss->pvqemu.guest_domid;
+
+    if (rc) {
+        if (rc == ERROR_TIMEDOUT)
+            LOG(ERROR, "%s: startup timed out", xswait->what);
+        goto out;
+    }
+
+    if (!p) return;
+
+    if (strcmp(p, "running"))
+        return;
  out:
+    libxl__xswait_stop(gc, xswait);
     if (rc) {
         if (dm_domid) {
-            sdss->dis.ao = ao;
+            sdss->dis.ao = sdss->dm.spawn.ao;
             sdss->dis.domid = dm_domid;
             sdss->dis.callback = spawn_stubdom_pvqemu_destroy_cb;
             libxl__destroy_domid(egc, &sdss->dis);

diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index ace8a66f5196be1fc05cbffe6a610fe69815ffb8..eb9e4995277f57de7e648bb6d14dd09086c1df66 100644 (file)
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -966,7 +966,8 @@ int libxl__qemu_traditional_cmd(libxl__gc *gc, uint32_t domid,
                                 const char *cmd)
 {
     char *path = NULL;
-    path = GCSPRINTF("/local/domain/0/device-model/%d/command", domid);
+    uint32_t dm_domid = libxl_get_stubdom_id(CTX, domid);
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/command");
     return libxl__xs_write(gc, XBT_NULL, path, "%s", cmd);
 }
 
@@ -980,11 +981,13 @@ struct libxl__physmap_info {
 
 #define TOOLSTACK_SAVE_VERSION 1
 
-static inline char *restore_helper(libxl__gc *gc, uint32_t domid,
-        uint64_t phys_offset, char *node)
+static inline char *restore_helper(libxl__gc *gc, uint32_t dm_domid,
+                                   uint32_t domid,
+                                   uint64_t phys_offset, char *node)
 {
-    return GCSPRINTF("/local/domain/0/device-model/%d/physmap/%"PRIx64"/%s",
-            domid, phys_offset, node);
+    return libxl__device_model_xs_path(gc, dm_domid, domid,
+                                       "/physmap/%"PRIx64"/%s",
+                                       phys_offset, node);
 }
 
 int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
@@ -998,6 +1001,7 @@ int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
     uint32_t count = 0, version = 0;
     struct libxl__physmap_info* pi;
     char *xs_path;
+    uint32_t dm_domid;
 
     LOG(DEBUG,"domain=%"PRIu32" toolstack data size=%"PRIu32, domid, size);
 
@@ -1023,20 +1027,23 @@ int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
         return -1;
     }
 
+    dm_domid = libxl_get_stubdom_id(CTX, domid);
     for (i = 0; i < count; i++) {
         pi = (struct libxl__physmap_info*) ptr;
         ptr += sizeof(struct libxl__physmap_info) + pi->namelen;
 
-        xs_path = restore_helper(gc, domid, pi->phys_offset, "start_addr");
+        xs_path = restore_helper(gc, dm_domid, domid,
+                                 pi->phys_offset, "start_addr");
         ret = libxl__xs_write(gc, 0, xs_path, "%"PRIx64, pi->start_addr);
         if (ret)
             return -1;
-        xs_path = restore_helper(gc, domid, pi->phys_offset, "size");
+        xs_path = restore_helper(gc, dm_domid, domid, pi->phys_offset, "size");
         ret = libxl__xs_write(gc, 0, xs_path, "%"PRIx64, pi->size);
         if (ret)
             return -1;
         if (pi->namelen > 0) {
-            xs_path = restore_helper(gc, domid, pi->phys_offset, "name");
+            xs_path = restore_helper(gc, dm_domid, domid,
+                                     pi->phys_offset, "name");
             ret = libxl__xs_write(gc, 0, xs_path, "%s", pi->name);
             if (ret)
                 return -1;
@@ -1089,10 +1096,11 @@ static void domain_suspend_switch_qemu_xen_traditional_logdirty
     const char *got;
 
     if (!lds->cmd_path) {
-        lds->cmd_path = GCSPRINTF(
-                   "/local/domain/0/device-model/%u/logdirty/cmd", domid);
-        lds->ret_path = GCSPRINTF(
-                   "/local/domain/0/device-model/%u/logdirty/ret", domid);
+        uint32_t dm_domid = libxl_get_stubdom_id(CTX, domid);
+        lds->cmd_path = libxl__device_model_xs_path(gc, dm_domid, domid,
+                                                    "/logdirty/cmd");
+        lds->ret_path = libxl__device_model_xs_path(gc, dm_domid, domid,
+                                                    "/logdirty/ret");
     }
     lds->cmd = enable ? "enable" : "disable";
 
@@ -1611,11 +1619,13 @@ static void domain_suspend_common_done(libxl__egc *egc,
     dss->callback_common_done(egc, dss, ok);
 }
 
-static inline char *physmap_path(libxl__gc *gc, uint32_t domid,
-        char *phys_offset, char *node)
+static inline char *physmap_path(libxl__gc *gc, uint32_t dm_domid,
+                                 uint32_t domid,
+                                 char *phys_offset, char *node)
 {
-    return GCSPRINTF("/local/domain/0/device-model/%d/physmap/%s/%s",
-            domid, phys_offset, node);
+    return libxl__device_model_xs_path(gc, dm_domid, domid,
+                                       "/physmap/%s/%s",
+                                       phys_offset, node);
 }
 
 int libxl__toolstack_save(uint32_t domid, uint8_t **buf,
@@ -1630,9 +1640,13 @@ int libxl__toolstack_save(uint32_t domid, uint8_t **buf,
     uint8_t *ptr = NULL;
     char **entries = NULL;
     struct libxl__physmap_info *pi;
+    uint32_t dm_domid;
+
+    dm_domid = libxl_get_stubdom_id(CTX, domid);
 
-    entries = libxl__xs_directory(gc, 0, GCSPRINTF(
-                "/local/domain/0/device-model/%d/physmap", domid), &num);
+    entries = libxl__xs_directory(gc, 0,
+                libxl__device_model_xs_path(gc, dm_domid, domid, "/physmap"),
+                &num);
     count = num;
 
     *len = sizeof(version) + sizeof(count);
@@ -1655,21 +1669,21 @@ int libxl__toolstack_save(uint32_t domid, uint8_t **buf,
             return -1;
         }
 
-        xs_path = physmap_path(gc, domid, phys_offset, "start_addr");
+        xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "start_addr");
         start_addr = libxl__xs_read(gc, 0, xs_path);
         if (start_addr == NULL) {
             LOG(ERROR, "%s is NULL", xs_path);
             return -1;
         }
 
-        xs_path = physmap_path(gc, domid, phys_offset, "size");
+        xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "size");
         size = libxl__xs_read(gc, 0, xs_path);
         if (size == NULL) {
             LOG(ERROR, "%s is NULL", xs_path);
             return -1;
         }
 
-        xs_path = physmap_path(gc, domid, phys_offset, "name");
+        xs_path = physmap_path(gc, dm_domid, domid, phys_offset, "name");
         name = libxl__xs_read(gc, 0, xs_path);
         if (name == NULL)
             namelen = 0;

diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 8da2b7f1edafd3aaba071f987cbaf6c4e7563774..144ff8566d7f415537325109348eaf20f6e9c93f 100644 (file)
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -86,6 +86,7 @@
 #define LIBXL_DESTROY_TIMEOUT 10
 #define LIBXL_HOTPLUG_TIMEOUT 10
 #define LIBXL_DEVICE_MODEL_START_TIMEOUT 10
+#define LIBXL_STUBDOM_START_TIMEOUT 30
 #define LIBXL_QEMU_BODGE_TIMEOUT 2
 #define LIBXL_XENCONSOLE_LIMIT 1048576
 #define LIBXL_XENCONSOLE_PROTOCOL "vt100"
@@ -3072,6 +3073,7 @@ typedef struct {
     libxl__dm_spawn_state pvqemu;
     libxl__destroy_domid_state dis;
     libxl__multidev multidev;
+    libxl__xswait_state xswait;
 } libxl__stub_dm_spawn_state;
 
 _hidden void libxl__spawn_stub_dm(libxl__egc *egc, libxl__stub_dm_spawn_state*);

diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c
index f3ae1329ff6e3a755b51bc494376a8f41afdf986..394f61c128a9cda80cce9229f249751704814692 100644 (file)
--- a/tools/libxl/libxl_pci.c
+++ b/tools/libxl/libxl_pci.c
@@ -850,11 +850,12 @@ static int qemu_pci_add_xenstore(libxl__gc *gc, uint32_t domid,
     int rc = 0;
     char *path;
     char *state, *vdevfn;
+    uint32_t dm_domid;
 
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
+    dm_domid = libxl_get_stubdom_id(CTX, domid);
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
     state = libxl__xs_read(gc, XBT_NULL, path);
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/parameter",
-                          domid);
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/parameter");
     if (pcidev->vdevfn) {
         libxl__xs_write(gc, XBT_NULL, path, PCI_BDF_VDEVFN","PCI_OPTIONS,
                         pcidev->domain, pcidev->bus, pcidev->dev,
@@ -869,11 +870,9 @@ static int qemu_pci_add_xenstore(libxl__gc *gc, uint32_t domid,
     libxl__qemu_traditional_cmd(gc, domid, "pci-ins");
     rc = libxl__wait_for_device_model_deprecated(gc, domid, NULL, NULL,
                                       pci_ins_check, state);
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/parameter",
-                          domid);
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/parameter");
     vdevfn = libxl__xs_read(gc, XBT_NULL, path);
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state",
-                          domid);
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
     if ( rc < 0 )
         LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
                    "qemu refused to add device: %s", vdevfn);
@@ -1175,10 +1174,13 @@ static int qemu_pci_remove_xenstore(libxl__gc *gc, uint32_t domid,
     libxl_ctx *ctx = libxl__gc_owner(gc);
     char *state;
     char *path;
+    uint32_t dm_domid;
 
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
+    dm_domid = libxl_get_stubdom_id(CTX, domid);
+
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
     state = libxl__xs_read(gc, XBT_NULL, path);
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/parameter", domid);
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/parameter");
     libxl__xs_write(gc, XBT_NULL, path, PCI_BDF, pcidev->domain,
                     pcidev->bus, pcidev->dev, pcidev->func);
 
@@ -1196,7 +1198,7 @@ static int qemu_pci_remove_xenstore(libxl__gc *gc, uint32_t domid,
             return ERROR_FAIL;
         }
     }
-    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
+    path = libxl__device_model_xs_path(gc, dm_domid, domid, "/state");
     xs_write(ctx->xsh, XBT_NULL, path, state, strlen(state));
 
     return 0;