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-rw-r--r--hw/xen/trace-events2
-rw-r--r--hw/xen/xen-bus.c94
-rw-r--r--include/hw/xen/xen-bus.h3
3 files changed, 74 insertions, 25 deletions
diff --git a/hw/xen/trace-events b/hw/xen/trace-events
index 80ce3dafad..e6885bc751 100644
--- a/hw/xen/trace-events
+++ b/hw/xen/trace-events
@@ -17,8 +17,10 @@ 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_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"
diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c
index 810a4e2df3..55c157393d 100644
--- a/hw/xen/xen-bus.c
+++ b/hw/xen/xen-bus.c
@@ -340,13 +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,
@@ -365,9 +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;
@@ -385,6 +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);
@@ -433,7 +476,7 @@ static void xen_bus_realize(BusState *bus, Error **errp)
xenbus->backend_watch =
xen_bus_add_watch(xenbus, "", /* domain root node */
- "backend", xen_bus_enumerate, &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,
@@ -555,9 +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:
@@ -594,30 +637,31 @@ 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(xendev->frontend_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);
}
}
diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h
index 0d198148f6..3d5532258d 100644
--- a/include/hw/xen/xen-bus.h
+++ b/include/hw/xen/xen-bus.h
@@ -32,7 +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);
@@ -68,6 +70,7 @@ typedef struct XenBus {
struct xs_handle *xsh;
XenWatchList *watch_list;
XenWatch *backend_watch;
+ QLIST_HEAD(, XenDevice) inactive_devices;
} XenBus;
typedef struct XenBusClass {
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-23 19:56:12 +0000