diff --git a/MAINTAINERS b/MAINTAINERS
index 1c56d45b16..bd7ee23101 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -406,7 +406,7 @@ Guest CPU Cores (Xen)
X86 Xen CPUs
M: Stefano Stabellini <sstabellini@kernel.org>
M: Anthony Perard <anthony.perard@citrix.com>
-M: Paul Durrant <paul.durrant@citrix.com>
+M: Paul Durrant <paul@xen.org>
L: xen-devel@lists.xenproject.org
S: Supported
F: */xen*
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index f77343db60..879fc310a4 100644
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -313,6 +313,7 @@ static void xen_block_frontend_changed(XenDevice *xendev,
break;
case XenbusStateClosed:
+ case XenbusStateUnknown:
xen_block_disconnect(xendev, &local_err);
if (local_err) {
error_propagate(errp, local_err);
diff --git a/hw/xen/trace-events b/hw/xen/trace-events
index bc82ecb1a5..e6885bc751 100644
--- a/hw/xen/trace-events
+++ b/hw/xen/trace-events
@@ -17,11 +17,12 @@ xen_domid_restrict(int err) "err: %u"
xen_bus_realize(void) ""
xen_bus_unrealize(void) ""
xen_bus_enumerate(void) ""
+xen_bus_cleanup(void) ""
xen_bus_type_enumerate(const char *type) "type: %s"
xen_bus_backend_create(const char *type, const char *path) "type: %s path: %s"
-xen_bus_add_watch(const char *node, const char *key, char *token) "node: %s key: %s token: %s"
-xen_bus_remove_watch(const char *node, const char *key, char *token) "node: %s key: %s token: %s"
-xen_bus_watch(const char *token) "token: %s"
+xen_bus_device_cleanup(const char *type, char *name) "type: %s name: %s"
+xen_bus_add_watch(const char *node, const char *key) "node: %s key: %s"
+xen_bus_remove_watch(const char *node, const char *key) "node: %s key: %s"
xen_device_realize(const char *type, char *name) "type: %s name: %s"
xen_device_unrealize(const char *type, char *name) "type: %s name: %s"
xen_device_backend_state(const char *type, char *name, const char *state) "type: %s name: %s -> %s"
@@ -30,6 +31,8 @@ xen_device_backend_changed(const char *type, char *name) "type: %s name: %s"
xen_device_frontend_state(const char *type, char *name, const char *state) "type: %s name: %s -> %s"
xen_device_frontend_changed(const char *type, char *name) "type: %s name: %s"
xen_device_unplug(const char *type, char *name) "type: %s name: %s"
+xen_device_add_watch(const char *type, char *name, const char *node, const char *key) "type: %s name: %s node: %s key: %s"
+xen_device_remove_watch(const char *type, char *name, const char *node, const char *key) "type: %s name: %s node: %s key: %s"
# xen-bus-helper.c
xs_node_create(const char *node) "%s"
diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c
index a04478ad4f..c2ad22a42d 100644
--- a/hw/xen/xen-bus.c
+++ b/hw/xen/xen-bus.c
@@ -157,18 +157,60 @@ static void free_watch(XenWatch *watch)
g_free(watch);
}
-static XenWatch *xen_bus_add_watch(XenBus *xenbus, const char *node,
- const char *key, XenWatchHandler handler,
- void *opaque, Error **errp)
+struct XenWatchList {
+ struct xs_handle *xsh;
+ NotifierList notifiers;
+};
+
+static void watch_list_event(void *opaque)
+{
+ XenWatchList *watch_list = opaque;
+ char **v;
+ const char *token;
+
+ v = xs_check_watch(watch_list->xsh);
+ if (!v) {
+ return;
+ }
+
+ token = v[XS_WATCH_TOKEN];
+
+ notifier_list_notify(&watch_list->notifiers, (void *)token);
+
+ free(v);
+}
+
+static XenWatchList *watch_list_create(struct xs_handle *xsh)
+{
+ XenWatchList *watch_list = g_new0(XenWatchList, 1);
+
+ g_assert(xsh);
+
+ watch_list->xsh = xsh;
+ notifier_list_init(&watch_list->notifiers);
+ qemu_set_fd_handler(xs_fileno(watch_list->xsh), watch_list_event, NULL,
+ watch_list);
+
+ return watch_list;
+}
+
+static void watch_list_destroy(XenWatchList *watch_list)
+{
+ g_assert(notifier_list_empty(&watch_list->notifiers));
+ qemu_set_fd_handler(xs_fileno(watch_list->xsh), NULL, NULL, NULL);
+ g_free(watch_list);
+}
+
+static XenWatch *watch_list_add(XenWatchList *watch_list, const char *node,
+ const char *key, XenWatchHandler handler,
+ void *opaque, Error **errp)
{
XenWatch *watch = new_watch(node, key, handler, opaque);
Error *local_err = NULL;
- trace_xen_bus_add_watch(watch->node, watch->key, watch->token);
+ notifier_list_add(&watch_list->notifiers, &watch->notifier);
- notifier_list_add(&xenbus->watch_notifiers, &watch->notifier);
-
- xs_node_watch(xenbus->xsh, node, key, watch->token, &local_err);
+ xs_node_watch(watch_list->xsh, node, key, watch->token, &local_err);
if (local_err) {
error_propagate(errp, local_err);
@@ -181,18 +223,34 @@ static XenWatch *xen_bus_add_watch(XenBus *xenbus, const char *node,
return watch;
}
-static void xen_bus_remove_watch(XenBus *xenbus, XenWatch *watch,
- Error **errp)
+static void watch_list_remove(XenWatchList *watch_list, XenWatch *watch,
+ Error **errp)
{
- trace_xen_bus_remove_watch(watch->node, watch->key, watch->token);
-
- xs_node_unwatch(xenbus->xsh, watch->node, watch->key, watch->token,
+ xs_node_unwatch(watch_list->xsh, watch->node, watch->key, watch->token,
errp);
notifier_remove(&watch->notifier);
free_watch(watch);
}
+static XenWatch *xen_bus_add_watch(XenBus *xenbus, const char *node,
+ const char *key, XenWatchHandler handler,
+ Error **errp)
+{
+ trace_xen_bus_add_watch(node, key);
+
+ return watch_list_add(xenbus->watch_list, node, key, handler, xenbus,
+ errp);
+}
+
+static void xen_bus_remove_watch(XenBus *xenbus, XenWatch *watch,
+ Error **errp)
+{
+ trace_xen_bus_remove_watch(watch->node, watch->key);
+
+ watch_list_remove(xenbus->watch_list, watch, errp);
+}
+
static void xen_bus_backend_create(XenBus *xenbus, const char *type,
const char *name, char *path,
Error **errp)
@@ -282,13 +340,18 @@ static void xen_bus_type_enumerate(XenBus *xenbus, const char *type)
for (i = 0; i < n; i++) {
char *backend_path = g_strdup_printf("%s/%s", domain_path,
backend[i]);
- enum xenbus_state backend_state;
+ enum xenbus_state state;
+ unsigned int online;
if (xs_node_scanf(xenbus->xsh, XBT_NULL, backend_path, "state",
- NULL, "%u", &backend_state) != 1)
- backend_state = XenbusStateUnknown;
+ NULL, "%u", &state) != 1)
+ state = XenbusStateUnknown;
- if (backend_state == XenbusStateInitialising) {
+ if (xs_node_scanf(xenbus->xsh, XBT_NULL, backend_path, "online",
+ NULL, "%u", &online) != 1)
+ online = 0;
+
+ if (online && state == XenbusStateInitialising) {
Error *local_err = NULL;
xen_bus_backend_create(xenbus, type, backend[i], backend_path,
@@ -307,9 +370,8 @@ out:
g_free(domain_path);
}
-static void xen_bus_enumerate(void *opaque)
+static void xen_bus_enumerate(XenBus *xenbus)
{
- XenBus *xenbus = opaque;
char **type;
unsigned int i, n;
@@ -327,6 +389,45 @@ static void xen_bus_enumerate(void *opaque)
free(type);
}
+static void xen_bus_device_cleanup(XenDevice *xendev)
+{
+ const char *type = object_get_typename(OBJECT(xendev));
+ Error *local_err = NULL;
+
+ trace_xen_bus_device_cleanup(type, xendev->name);
+
+ g_assert(!xendev->backend_online);
+
+ if (!xen_backend_try_device_destroy(xendev, &local_err)) {
+ object_unparent(OBJECT(xendev));
+ }
+
+ if (local_err) {
+ error_report_err(local_err);
+ }
+}
+
+static void xen_bus_cleanup(XenBus *xenbus)
+{
+ XenDevice *xendev, *next;
+
+ trace_xen_bus_cleanup();
+
+ QLIST_FOREACH_SAFE(xendev, &xenbus->inactive_devices, list, next) {
+ g_assert(xendev->inactive);
+ QLIST_REMOVE(xendev, list);
+ xen_bus_device_cleanup(xendev);
+ }
+}
+
+static void xen_bus_backend_changed(void *opaque)
+{
+ XenBus *xenbus = opaque;
+
+ xen_bus_enumerate(xenbus);
+ xen_bus_cleanup(xenbus);
+}
+
static void xen_bus_unrealize(BusState *bus, Error **errp)
{
XenBus *xenbus = XEN_BUS(bus);
@@ -338,35 +439,14 @@ static void xen_bus_unrealize(BusState *bus, Error **errp)
xenbus->backend_watch = NULL;
}
- if (!xenbus->xsh) {
- return;
+ if (xenbus->watch_list) {
+ watch_list_destroy(xenbus->watch_list);
+ xenbus->watch_list = NULL;
}
- qemu_set_fd_handler(xs_fileno(xenbus->xsh), NULL, NULL, NULL);
-
- xs_close(xenbus->xsh);
-}
-
-static void xen_bus_watch(void *opaque)
-{
- XenBus *xenbus = opaque;
- char **v;
- const char *token;
-
- g_assert(xenbus->xsh);
-
- v = xs_check_watch(xenbus->xsh);
- if (!v) {
- return;
+ if (xenbus->xsh) {
+ xs_close(xenbus->xsh);
}
-
- token = v[XS_WATCH_TOKEN];
-
- trace_xen_bus_watch(token);
-
- notifier_list_notify(&xenbus->watch_notifiers, (void *)token);
-
- free(v);
}
static void xen_bus_realize(BusState *bus, Error **errp)
@@ -390,15 +470,13 @@ static void xen_bus_realize(BusState *bus, Error **errp)
xenbus->backend_id = 0; /* Assume lack of node means dom0 */
}
- notifier_list_init(&xenbus->watch_notifiers);
- qemu_set_fd_handler(xs_fileno(xenbus->xsh), xen_bus_watch, NULL,
- xenbus);
+ xenbus->watch_list = watch_list_create(xenbus->xsh);
module_call_init(MODULE_INIT_XEN_BACKEND);
xenbus->backend_watch =
xen_bus_add_watch(xenbus, "", /* domain root node */
- "backend", xen_bus_enumerate, xenbus, &local_err);
+ "backend", xen_bus_backend_changed, &local_err);
if (local_err) {
/* This need not be treated as a hard error so don't propagate */
error_reportf_err(local_err,
@@ -520,9 +598,9 @@ static void xen_device_backend_set_online(XenDevice *xendev, bool online)
* Tell from the state whether the frontend is likely alive,
* i.e. it will react to a change of state of the backend.
*/
-static bool xen_device_state_is_active(enum xenbus_state state)
+static bool xen_device_frontend_is_active(XenDevice *xendev)
{
- switch (state) {
+ switch (xendev->frontend_state) {
case XenbusStateInitWait:
case XenbusStateInitialised:
case XenbusStateConnected:
@@ -559,33 +637,59 @@ static void xen_device_backend_changed(void *opaque)
* state to Closing, but there is no active frontend then set the
* backend state to Closed.
*/
- if (xendev->backend_state == XenbusStateClosing &&
- !xen_device_state_is_active(state)) {
+ if (state == XenbusStateClosing &&
+ !xen_device_frontend_is_active(xendev)) {
xen_device_backend_set_state(xendev, XenbusStateClosed);
}
/*
* If a backend is still 'online' then we should leave it alone but,
- * if a backend is not 'online', then the device should be destroyed
- * once the state is Closed.
+ * if a backend is not 'online', then the device is a candidate
+ * for destruction. Hence add it to the 'inactive' list to be cleaned
+ * by xen_bus_cleanup().
*/
- if (!xendev->backend_online &&
- (xendev->backend_state == XenbusStateClosed ||
- xendev->backend_state == XenbusStateInitialising ||
- xendev->backend_state == XenbusStateInitWait ||
- xendev->backend_state == XenbusStateUnknown)) {
- Error *local_err = NULL;
+ if (!online &&
+ (state == XenbusStateClosed || state == XenbusStateInitialising ||
+ state == XenbusStateInitWait || state == XenbusStateUnknown) &&
+ !xendev->inactive) {
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
- if (!xen_backend_try_device_destroy(xendev, &local_err)) {
- object_unparent(OBJECT(xendev));
- }
+ xendev->inactive = true;
+ QLIST_INSERT_HEAD(&xenbus->inactive_devices, xendev, list);
- if (local_err) {
- error_report_err(local_err);
- }
+ /*
+ * Re-write the state to cause a XenBus backend_watch notification,
+ * resulting in a call to xen_bus_cleanup().
+ */
+ xen_device_backend_printf(xendev, "state", "%u", state);
}
}
+static XenWatch *xen_device_add_watch(XenDevice *xendev, const char *node,
+ const char *key,
+ XenWatchHandler handler,
+ Error **errp)
+{
+ const char *type = object_get_typename(OBJECT(xendev));
+
+ trace_xen_device_add_watch(type, xendev->name, node, key);
+
+ return watch_list_add(xendev->watch_list, node, key, handler, xendev,
+ errp);
+}
+
+static void xen_device_remove_watch(XenDevice *xendev, XenWatch *watch,
+ Error **errp)
+{
+ const char *type = object_get_typename(OBJECT(xendev));
+
+ trace_xen_device_remove_watch(type, xendev->name, watch->node,
+ watch->key);
+
+ watch_list_remove(xendev->watch_list, watch, errp);
+}
+
+
static void xen_device_backend_create(XenDevice *xendev, Error **errp)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
@@ -610,9 +714,9 @@ static void xen_device_backend_create(XenDevice *xendev, Error **errp)
}
xendev->backend_state_watch =
- xen_bus_add_watch(xenbus, xendev->backend_path,
- "state", xen_device_backend_changed,
- xendev, &local_err);
+ xen_device_add_watch(xendev, xendev->backend_path,
+ "state", xen_device_backend_changed,
+ &local_err);
if (local_err) {
error_propagate_prepend(errp, local_err,
"failed to watch backend state: ");
@@ -620,9 +724,9 @@ static void xen_device_backend_create(XenDevice *xendev, Error **errp)
}
xendev->backend_online_watch =
- xen_bus_add_watch(xenbus, xendev->backend_path,
- "online", xen_device_backend_changed,
- xendev, &local_err);
+ xen_device_add_watch(xendev, xendev->backend_path,
+ "online", xen_device_backend_changed,
+ &local_err);
if (local_err) {
error_propagate_prepend(errp, local_err,
"failed to watch backend online: ");
@@ -636,12 +740,12 @@ static void xen_device_backend_destroy(XenDevice *xendev)
Error *local_err = NULL;
if (xendev->backend_online_watch) {
- xen_bus_remove_watch(xenbus, xendev->backend_online_watch, NULL);
+ xen_device_remove_watch(xendev, xendev->backend_online_watch, NULL);
xendev->backend_online_watch = NULL;
}
if (xendev->backend_state_watch) {
- xen_bus_remove_watch(xenbus, xendev->backend_state_watch, NULL);
+ xen_device_remove_watch(xendev, xendev->backend_state_watch, NULL);
xendev->backend_state_watch = NULL;
}
@@ -753,6 +857,13 @@ static void xen_device_frontend_changed(void *opaque)
}
}
+static bool xen_device_frontend_exists(XenDevice *xendev)
+{
+ enum xenbus_state state;
+
+ return (xen_device_frontend_scanf(xendev, "state", "%u", &state) == 1);
+}
+
static void xen_device_frontend_create(XenDevice *xendev, Error **errp)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
@@ -761,24 +872,30 @@ static void xen_device_frontend_create(XenDevice *xendev, Error **errp)
xendev->frontend_path = xen_device_get_frontend_path(xendev);
- perms[0].id = xendev->frontend_id;
- perms[0].perms = XS_PERM_NONE;
- perms[1].id = xenbus->backend_id;
- perms[1].perms = XS_PERM_READ | XS_PERM_WRITE;
+ /*
+ * The frontend area may have already been created by a legacy
+ * toolstack.
+ */
+ if (!xen_device_frontend_exists(xendev)) {
+ perms[0].id = xendev->frontend_id;
+ perms[0].perms = XS_PERM_NONE;
+ perms[1].id = xenbus->backend_id;
+ perms[1].perms = XS_PERM_READ | XS_PERM_WRITE;
- g_assert(xenbus->xsh);
+ g_assert(xenbus->xsh);
- xs_node_create(xenbus->xsh, XBT_NULL, xendev->frontend_path, perms,
- ARRAY_SIZE(perms), &local_err);
- if (local_err) {
- error_propagate_prepend(errp, local_err,
- "failed to create frontend: ");
- return;
+ xs_node_create(xenbus->xsh, XBT_NULL, xendev->frontend_path, perms,
+ ARRAY_SIZE(perms), &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err,
+ "failed to create frontend: ");
+ return;
+ }
}
xendev->frontend_state_watch =
- xen_bus_add_watch(xenbus, xendev->frontend_path, "state",
- xen_device_frontend_changed, xendev, &local_err);
+ xen_device_add_watch(xendev, xendev->frontend_path, "state",
+ xen_device_frontend_changed, &local_err);
if (local_err) {
error_propagate_prepend(errp, local_err,
"failed to watch frontend state: ");
@@ -791,7 +908,8 @@ static void xen_device_frontend_destroy(XenDevice *xendev)
Error *local_err = NULL;
if (xendev->frontend_state_watch) {
- xen_bus_remove_watch(xenbus, xendev->frontend_state_watch, NULL);
+ xen_device_remove_watch(xendev, xendev->frontend_state_watch,
+ NULL);
xendev->frontend_state_watch = NULL;
}
@@ -1087,6 +1205,16 @@ static void xen_device_unrealize(DeviceState *dev, Error **errp)
xendev->xgth = NULL;
}
+ if (xendev->watch_list) {
+ watch_list_destroy(xendev->watch_list);
+ xendev->watch_list = NULL;
+ }
+
+ if (xendev->xsh) {
+ xs_close(xendev->xsh);
+ xendev->xsh = NULL;
+ }
+
g_free(xendev->name);
xendev->name = NULL;
}
@@ -1129,6 +1257,14 @@ static void xen_device_realize(DeviceState *dev, Error **errp)
trace_xen_device_realize(type, xendev->name);
+ xendev->xsh = xs_open(0);
+ if (!xendev->xsh) {
+ error_setg_errno(errp, errno, "failed xs_open");
+ goto unrealize;
+ }
+
+ xendev->watch_list = watch_list_create(xendev->xsh);
+
xendev->xgth = xengnttab_open(NULL, 0);
if (!xendev->xgth) {
error_setg_errno(errp, errno, "failed xengnttab_open");
@@ -1167,12 +1303,14 @@ static void xen_device_realize(DeviceState *dev, Error **errp)
xen_device_backend_set_online(xendev, true);
xen_device_backend_set_state(xendev, XenbusStateInitWait);
- xen_device_frontend_printf(xendev, "backend", "%s",
- xendev->backend_path);
- xen_device_frontend_printf(xendev, "backend-id", "%u",
- xenbus->backend_id);
+ if (!xen_device_frontend_exists(xendev)) {
+ xen_device_frontend_printf(xendev, "backend", "%s",
+ xendev->backend_path);
+ xen_device_frontend_printf(xendev, "backend-id", "%u",
+ xenbus->backend_id);
- xen_device_frontend_set_state(xendev, XenbusStateInitialising, true);
+ xen_device_frontend_set_state(xendev, XenbusStateInitialising, true);
+ }
xendev->exit.notify = xen_device_exit;
qemu_add_exit_notifier(&xendev->exit);
diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h
index 1c2d9dfdb8..3d5532258d 100644
--- a/include/hw/xen/xen-bus.h
+++ b/include/hw/xen/xen-bus.h
@@ -14,6 +14,7 @@
typedef void (*XenWatchHandler)(void *opaque);
+typedef struct XenWatchList XenWatchList;
typedef struct XenWatch XenWatch;
typedef struct XenEventChannel XenEventChannel;
@@ -21,6 +22,8 @@ typedef struct XenDevice {
DeviceState qdev;
domid_t frontend_id;
char *name;
+ struct xs_handle *xsh;
+ XenWatchList *watch_list;
char *backend_path, *frontend_path;
enum xenbus_state backend_state, frontend_state;
Notifier exit;
@@ -29,7 +32,9 @@ typedef struct XenDevice {
XenWatch *backend_online_watch;
xengnttab_handle *xgth;
bool feature_grant_copy;
+ bool inactive;
QLIST_HEAD(, XenEventChannel) event_channels;
+ QLIST_ENTRY(XenDevice) list;
} XenDevice;
typedef char *(*XenDeviceGetName)(XenDevice *xendev, Error **errp);
@@ -63,8 +68,9 @@ typedef struct XenBus {
BusState qbus;
domid_t backend_id;
struct xs_handle *xsh;
- NotifierList watch_notifiers;
+ XenWatchList *watch_list;
XenWatch *backend_watch;
+ QLIST_HEAD(, XenDevice) inactive_devices;
} XenBus;
typedef struct XenBusClass {
diff --git a/include/qemu/notify.h b/include/qemu/notify.h
index a3d73e4bc7..bcfa70fb2e 100644
--- a/include/qemu/notify.h
+++ b/include/qemu/notify.h
@@ -40,6 +40,8 @@ void notifier_remove(Notifier *notifier);
void notifier_list_notify(NotifierList *list, void *data);
+bool notifier_list_empty(NotifierList *list);
+
/* Same as Notifier but allows .notify() to return errors */
typedef struct NotifierWithReturn NotifierWithReturn;
diff --git a/util/notify.c b/util/notify.c
index aee8d93cb0..76bab212ae 100644
--- a/util/notify.c
+++ b/util/notify.c
@@ -40,6 +40,11 @@ void notifier_list_notify(NotifierList *list, void *data)
}
}
+bool notifier_list_empty(NotifierList *list)
+{
+ return QLIST_EMPTY(&list->notifiers);
+}
+
void notifier_with_return_list_init(NotifierWithReturnList *list)
{
QLIST_INIT(&list->notifiers);