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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 04/18] xen: create xenstore areas for XenDevice-s
This patch adds a new source module, xen-bus-helper.c, which builds on
basic libxenstore primitives to provide functions to create (setting
permissions appropriately) and destroy xenstore areas, and functions to
'printf' and 'scanf' nodes therein. The main xen-bus code then uses
these primitives [1] to initialize and destroy the frontend and backend
areas for a XenDevice during realize and unrealize respectively.
The 'xen-qdisk' implementation is extended with a 'get_name' method that
returns the VBD number. This number is reqired to 'name' the xenstore
areas.
NOTE: An exit handler is also added to make sure the xenstore areas are
cleaned up if QEMU terminates without devices being unrealized.
[1] The 'scanf' functions are actually not yet needed, but they will be
needed by code delivered in subsequent patches.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Anthony Perard <anthony.perard@xxxxxxxxxx>
Cc: Kevin Wolf <kwolf@xxxxxxxxxx>
Cc: Max Reitz <mreitz@xxxxxxxxxx>
---
hw/block/xen-qdisk.c | 11 ++
hw/xen/Makefile.objs | 2 +-
hw/xen/trace-events | 6 +-
hw/xen/xen-bus-helper.c | 124 +++++++++++++++++
hw/xen/xen-bus.c | 288 +++++++++++++++++++++++++++++++++++++++-
include/hw/xen/xen-bus-helper.h | 26 ++++
include/hw/xen/xen-bus.h | 12 ++
7 files changed, 464 insertions(+), 5 deletions(-)
create mode 100644 hw/xen/xen-bus-helper.c
create mode 100644 include/hw/xen/xen-bus-helper.h
diff --git a/hw/block/xen-qdisk.c b/hw/block/xen-qdisk.c
index 72122073f7..0859643f7d 100644
--- a/hw/block/xen-qdisk.c
+++ b/hw/block/xen-qdisk.c
@@ -11,6 +11,14 @@
#include "hw/xen/xen-qdisk.h"
#include "trace.h"
+static char *xen_qdisk_get_name(XenDevice *xendev, Error **errp)
+{
+ XenQdiskDevice *qdiskdev = XEN_QDISK_DEVICE(xendev);
+ XenQdiskVdev *vdev = &qdiskdev->vdev;
+
+ return g_strdup_printf("%lu", vdev->number);
+}
+
static void xen_qdisk_realize(XenDevice *xendev, Error **errp)
{
XenQdiskDevice *qdiskdev = XEN_QDISK_DEVICE(xendev);
@@ -234,6 +242,9 @@ static void xen_qdisk_class_init(ObjectClass *class, void
*data)
DeviceClass *dev_class = DEVICE_CLASS(class);
XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
+ xendev_class->backend = "qdisk";
+ xendev_class->device = "vbd";
+ xendev_class->get_name = xen_qdisk_get_name;
xendev_class->realize = xen_qdisk_realize;
xendev_class->unrealize = xen_qdisk_unrealize;
diff --git a/hw/xen/Makefile.objs b/hw/xen/Makefile.objs
index d9d6d7b4f9..77c0868190 100644
--- a/hw/xen/Makefile.objs
+++ b/hw/xen/Makefile.objs
@@ -1,5 +1,5 @@
# xen backend driver support
-common-obj-$(CONFIG_XEN) += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o
xen-common.o xen-bus.o
+common-obj-$(CONFIG_XEN) += xen-legacy-backend.o xen_devconfig.o xen_pvdev.o
xen-common.o xen-bus.o xen-bus-helper.o
obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen-host-pci-device.o
obj-$(CONFIG_XEN_PCI_PASSTHROUGH) += xen_pt.o xen_pt_config_init.o
xen_pt_graphics.o xen_pt_msi.o
diff --git a/hw/xen/trace-events b/hw/xen/trace-events
index 0172cd4e26..fa8aea1da1 100644
--- a/hw/xen/trace-events
+++ b/hw/xen/trace-events
@@ -16,5 +16,7 @@ xen_domid_restrict(int err) "err: %u"
# include/hw/xen/xen-bus.c
xen_bus_realize(void) ""
xen_bus_unrealize(void) ""
-xen_device_realize(const char *type) "type: %s"
-xen_device_unrealize(const char *type) "type: %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"
+xen_device_frontend_state(const char *type, char *name, const char *state)
"type: %s name: %s -> %s"
diff --git a/hw/xen/xen-bus-helper.c b/hw/xen/xen-bus-helper.c
new file mode 100644
index 0000000000..d9ee2ed6a0
--- /dev/null
+++ b/hw/xen/xen-bus-helper.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) Citrix Systems Inc.
+ * All rights reserved.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/hw.h"
+#include "hw/sysbus.h"
+#include "hw/xen/xen.h"
+#include "hw/xen/xen-bus.h"
+#include "hw/xen/xen-bus-helper.h"
+#include "qapi/error.h"
+
+struct xs_state {
+ enum xenbus_state statenum;
+ const char *statestr;
+};
+#define XS_STATE(state) { state, #state }
+
+static struct xs_state xs_state[] = {
+ XS_STATE(XenbusStateUnknown),
+ XS_STATE(XenbusStateInitialising),
+ XS_STATE(XenbusStateInitWait),
+ XS_STATE(XenbusStateInitialised),
+ XS_STATE(XenbusStateConnected),
+ XS_STATE(XenbusStateClosing),
+ XS_STATE(XenbusStateClosed),
+ XS_STATE(XenbusStateReconfiguring),
+ XS_STATE(XenbusStateReconfigured),
+};
+
+#undef XS_STATE
+
+const char *xs_strstate(enum xenbus_state state)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(xs_state); i++) {
+ if (xs_state[i].statenum == state) {
+ return xs_state[i].statestr;
+ }
+ }
+
+ return "INVALID";
+}
+
+void xs_node_create(struct xs_handle *xsh, const char *node,
+ struct xs_permissions perms[],
+ unsigned int nr_perms, Error **errp)
+{
+ if (!xs_write(xsh, XBT_NULL, node, "", 0)) {
+ error_setg_errno(errp, errno, "failed to create node '%s'", node);
+ return;
+ }
+
+ if (!xs_set_permissions(xsh, XBT_NULL, node,
+ perms, nr_perms)) {
+ error_setg_errno(errp, errno, "failed to set node '%s' permissions",
+ node);
+ }
+}
+
+void xs_node_destroy(struct xs_handle *xsh, const char *node)
+{
+ xs_rm(xsh, XBT_NULL, node);
+}
+
+void xs_node_vprintf(struct xs_handle *xsh, const char *node,
+ const char *key, const char *fmt, va_list ap)
+{
+ char *path, *value;
+
+ path = (strlen(node) != 0) ? g_strdup_printf("%s/%s", node, key) :
+ g_strdup(key);
+
+ value = g_strdup_vprintf(fmt, ap);
+
+ xs_write(xsh, XBT_NULL, path, value, strlen(value));
+
+ g_free(value);
+ g_free(path);
+}
+
+void xs_node_printf(struct xs_handle *xsh, const char *node,
+ const char *key, const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ xs_node_vprintf(xsh, node, key, fmt, ap);
+ va_end(ap);
+}
+
+int xs_node_vscanf(struct xs_handle *xsh, const char *node, const char *key,
+ const char *fmt, va_list ap)
+{
+ char *path, *value;
+ int rc;
+
+ path = (strlen(node) != 0) ? g_strdup_printf("%s/%s", node, key) :
+ g_strdup(key);
+
+ value = xs_read(xsh, XBT_NULL, path, NULL);
+
+ rc = value ? vsscanf(value, fmt, ap) : EOF;
+
+ free(value);
+ g_free(path);
+
+ return rc;
+}
+
+int xs_node_scanf(struct xs_handle *xsh, const char *node, const char *key,
+ const char *fmt, ...)
+{
+ va_list ap;
+ int rc;
+
+ va_start(ap, fmt);
+ rc = xs_node_vscanf(xsh, node, key, fmt, ap);
+ va_end(ap);
+
+ return rc;
+}
diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c
index dede2d914a..663aa8e117 100644
--- a/hw/xen/xen-bus.c
+++ b/hw/xen/xen-bus.c
@@ -6,24 +6,102 @@
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/sysbus.h"
+#include "hw/xen/xen.h"
#include "hw/xen/xen-bus.h"
+#include "hw/xen/xen-bus-helper.h"
+#include "monitor/monitor.h"
#include "qapi/error.h"
+#include "sysemu/sysemu.h"
#include "trace.h"
+static char *xen_device_get_backend_path(XenDevice *xendev)
+{
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
+ XenDeviceClass *xendev_class = XEN_DEVICE_GET_CLASS(xendev);
+ const char *type = object_get_typename(OBJECT(xendev));
+ const char *backend = xendev_class->backend;
+
+ if (!backend) {
+ backend = type;
+ }
+
+ return g_strdup_printf("/local/domain/%u/backend/%s/%u/%s",
+ xenbus->backend_id, backend, xendev->frontend_id,
+ xendev->name);
+}
+
+static char *xen_device_get_frontend_path(XenDevice *xendev)
+{
+ XenDeviceClass *xendev_class = XEN_DEVICE_GET_CLASS(xendev);
+ const char *type = object_get_typename(OBJECT(xendev));
+ const char *device = xendev_class->device;
+
+ if (!device) {
+ device = type;
+ }
+
+ return g_strdup_printf("/local/domain/%u/device/%s/%s",
+ xendev->frontend_id, device, xendev->name);
+}
+
+static void xen_bus_print_dev(Monitor *mon, DeviceState *dev, int indent)
+{
+ XenDevice *xendev = XEN_DEVICE(dev);
+
+ monitor_printf(mon, "%*sname = '%s' frontend_id = %u\n",
+ indent, "", xendev->name, xendev->frontend_id);
+}
+
+static char *xen_bus_get_dev_path(DeviceState *dev)
+{
+ return xen_device_get_backend_path(XEN_DEVICE(dev));
+}
+
static void xen_bus_unrealize(BusState *bus, Error **errp)
{
+ XenBus *xenbus = XEN_BUS(bus);
+
trace_xen_bus_unrealize();
+
+ if (!xenbus->xsh) {
+ return;
+ }
+
+ xs_close(xenbus->xsh);
}
static void xen_bus_realize(BusState *bus, Error **errp)
{
+ XenBus *xenbus = XEN_BUS(bus);
+ unsigned int domid;
+
trace_xen_bus_realize();
+
+ xenbus->xsh = xs_open(0);
+ if (!xenbus->xsh) {
+ error_setg_errno(errp, errno, "failed xs_open");
+ goto fail;
+ }
+
+ if (xs_node_scanf(xenbus->xsh, "", /* domain root node */
+ "domid", "%u", &domid) == 1) {
+ xenbus->backend_id = domid;
+ } else {
+ xenbus->backend_id = 0; /* Assume lack of node means dom0 */
+ }
+
+ return;
+
+fail:
+ xen_bus_unrealize(bus, &error_abort);
}
static void xen_bus_class_init(ObjectClass *class, void *data)
{
BusClass *bus_class = BUS_CLASS(class);
+ bus_class->print_dev = xen_bus_print_dev;
+ bus_class->get_dev_path = xen_bus_get_dev_path;
bus_class->realize = xen_bus_realize;
bus_class->unrealize = xen_bus_unrealize;
}
@@ -36,6 +114,138 @@ static const TypeInfo xen_bus_type_info = {
.class_init = xen_bus_class_init,
};
+static void xen_device_backend_printf(XenDevice *xendev, const char *key,
+ const char *fmt, ...)
+{
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
+ va_list ap;
+
+ g_assert(xenbus->xsh);
+
+ va_start(ap, fmt);
+ xs_node_vprintf(xenbus->xsh, xendev->backend_path, key, fmt, ap);
+ va_end(ap);
+}
+
+static void xen_device_backend_set_state(XenDevice *xendev,
+ enum xenbus_state state)
+{
+ const char *type = object_get_typename(OBJECT(xendev));
+
+ if (xendev->backend_state == state) {
+ return;
+ }
+
+ trace_xen_device_backend_state(type, xendev->name,
+ xs_strstate(state));
+
+ xendev->backend_state = state;
+ xen_device_backend_printf(xendev, "state", "%u", state);
+}
+
+static void xen_device_backend_create(XenDevice *xendev, Error **errp)
+{
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
+ struct xs_permissions perms[2];
+ Error *local_err = NULL;
+
+ xendev->backend_path = xen_device_get_backend_path(xendev);
+
+ perms[0].id = xenbus->backend_id;
+ perms[0].perms = XS_PERM_NONE;
+ perms[1].id = xendev->frontend_id;
+ perms[1].perms = XS_PERM_READ;
+
+ g_assert(xenbus->xsh);
+
+ xs_node_create(xenbus->xsh, xendev->backend_path, perms,
+ ARRAY_SIZE(perms), &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ error_prepend(errp, "failed to create backend: ");
+ }
+}
+
+static void xen_device_backend_destroy(XenDevice *xendev)
+{
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
+
+ if (!xendev->backend_path) {
+ return;
+ }
+
+ g_assert(xenbus->xsh);
+
+ xs_node_destroy(xenbus->xsh, xendev->backend_path);
+ g_free(xendev->backend_path);
+}
+
+static void xen_device_frontend_printf(XenDevice *xendev, const char *key,
+ const char *fmt, ...)
+{
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
+ va_list ap;
+
+ g_assert(xenbus->xsh);
+
+ va_start(ap, fmt);
+ xs_node_vprintf(xenbus->xsh, xendev->frontend_path, key, fmt, ap);
+ va_end(ap);
+}
+
+static void xen_device_frontend_set_state(XenDevice *xendev,
+ enum xenbus_state state)
+{
+ const char *type = object_get_typename(OBJECT(xendev));
+
+ if (xendev->frontend_state == state) {
+ return;
+ }
+
+ trace_xen_device_frontend_state(type, xendev->name,
+ xs_strstate(state));
+
+ xendev->frontend_state = state;
+ xen_device_frontend_printf(xendev, "state", "%u", state);
+}
+
+static void xen_device_frontend_create(XenDevice *xendev, Error **errp)
+{
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
+ struct xs_permissions perms[2];
+ Error *local_err = NULL;
+
+ 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;
+
+ g_assert(xenbus->xsh);
+
+ xs_node_create(xenbus->xsh, xendev->frontend_path, perms,
+ ARRAY_SIZE(perms), &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ error_prepend(errp, "failed to create frontend: ");
+ }
+}
+
+static void xen_device_frontend_destroy(XenDevice *xendev)
+{
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
+
+ if (!xendev->frontend_path) {
+ return;
+ }
+
+ g_assert(xenbus->xsh);
+
+ xs_node_destroy(xenbus->xsh, xendev->frontend_path);
+ g_free(xendev->frontend_path);
+}
+
static void xen_device_unrealize(DeviceState *dev, Error **errp)
{
XenDevice *xendev = XEN_DEVICE(dev);
@@ -43,7 +253,10 @@ static void xen_device_unrealize(DeviceState *dev, Error
**errp)
const char *type = object_get_typename(OBJECT(xendev));
Error *local_err = NULL;
- trace_xen_device_unrealize(type);
+ trace_xen_device_unrealize(type, xendev->name);
+
+ if (xendev->exit.notify)
+ qemu_remove_exit_notifier(&xendev->exit);
if (xendev_class->unrealize) {
xendev_class->unrealize(xendev, &local_err);
@@ -52,16 +265,62 @@ static void xen_device_unrealize(DeviceState *dev, Error
**errp)
return;
}
}
+
+ xen_device_frontend_destroy(xendev);
+ xen_device_backend_destroy(xendev);
+
+ g_free(xendev->name);
+}
+
+static void xen_device_exit(Notifier *n, void *data)
+{
+ XenDevice *xendev = container_of(n, XenDevice, exit);
+
+ xen_device_unrealize(DEVICE(xendev), &error_abort);
}
static void xen_device_realize(DeviceState *dev, Error **errp)
{
XenDevice *xendev = XEN_DEVICE(dev);
XenDeviceClass *xendev_class = XEN_DEVICE_GET_CLASS(xendev);
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
const char *type = object_get_typename(OBJECT(xendev));
Error *local_err = NULL;
- trace_xen_device_realize(type);
+ if (xendev->frontend_id == DOMID_INVALID) {
+ xendev->frontend_id = xen_domid;
+ }
+
+ if (xendev->frontend_id >= DOMID_FIRST_RESERVED) {
+ error_setg(errp, "invalid frontend-id");
+ return;
+ }
+
+ if (!xendev_class->get_name) {
+ error_setg(errp, "get_name method not implemented");
+ return;
+ }
+
+ xendev->name = xendev_class->get_name(xendev, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ error_prepend(errp, "failed to get device name: ");
+ return;
+ }
+
+ trace_xen_device_realize(type, xendev->name);
+
+ xen_device_backend_create(xendev, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ goto unrealize;
+ }
+
+ xen_device_frontend_create(xendev, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ goto unrealize;
+ }
if (xendev_class->realize) {
xendev_class->realize(xendev, &local_err);
@@ -71,18 +330,43 @@ static void xen_device_realize(DeviceState *dev, Error
**errp)
}
}
+ xen_device_backend_printf(xendev, "frontend", "%s",
+ xendev->frontend_path);
+ xen_device_backend_printf(xendev, "frontend-id", "%u",
+ xendev->frontend_id);
+ xen_device_backend_printf(xendev, "online", "%u", 1);
+ xen_device_backend_printf(xendev, "hotplug-status", "connected");
+
+ 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);
+
+ xen_device_frontend_set_state(xendev, XenbusStateInitialising);
+
+ xendev->exit.notify = xen_device_exit;
+ qemu_add_exit_notifier(&xendev->exit);
return;
unrealize:
xen_device_unrealize(dev, &error_abort);
}
+static Property xen_device_props[] = {
+ DEFINE_PROP_UINT16("frontend-id", XenDevice, frontend_id,
+ DOMID_INVALID),
+ DEFINE_PROP_END_OF_LIST()
+};
+
static void xen_device_class_init(ObjectClass *class, void *data)
{
DeviceClass *dev_class = DEVICE_CLASS(class);
dev_class->realize = xen_device_realize;
dev_class->unrealize = xen_device_unrealize;
+ dev_class->props = xen_device_props;
dev_class->bus_type = TYPE_XEN_BUS;
}
diff --git a/include/hw/xen/xen-bus-helper.h b/include/hw/xen/xen-bus-helper.h
new file mode 100644
index 0000000000..53570650db
--- /dev/null
+++ b/include/hw/xen/xen-bus-helper.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) Citrix Systems Inc.
+ * All rights reserved.
+ */
+
+#ifndef HW_XEN_BUS_HELPER_H
+#define HW_XEN_BUS_HELPER_H
+
+const char *xs_strstate(enum xenbus_state state);
+
+void xs_node_create(struct xs_handle *xsh, const char *node,
+ struct xs_permissions perms[],
+ unsigned int nr_perms, Error **errp);
+void xs_node_destroy(struct xs_handle *xsh, const char *node);
+
+void xs_node_vprintf(struct xs_handle *xsh, const char *node,
+ const char *key, const char *fmt, va_list ap);
+void xs_node_printf(struct xs_handle *xsh, const char *node, const char *key,
+ const char *fmt, ...);
+
+int xs_node_vscanf(struct xs_handle *xsh, const char *node, const char *key,
+ const char *fmt, va_list ap);
+int xs_node_scanf(struct xs_handle *xsh, const char *node, const char *key,
+ const char *fmt, ...);
+
+#endif /* HW_XEN_BUS_HELPER_H */
diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h
index 41772dc73a..434d1dbf58 100644
--- a/include/hw/xen/xen-bus.h
+++ b/include/hw/xen/xen-bus.h
@@ -6,12 +6,19 @@
#ifndef HW_XEN_BUS_H
#define HW_XEN_BUS_H
+#include "hw/xen/xen_common.h"
#include "hw/sysbus.h"
typedef struct XenDevice {
DeviceState qdev;
+ domid_t frontend_id;
+ char *name;
+ char *backend_path, *frontend_path;
+ enum xenbus_state backend_state, frontend_state;
+ Notifier exit;
} XenDevice;
+typedef char *(*XenDeviceGetName)(XenDevice *xendev, Error **errp);
typedef void (*XenDeviceRealize)(XenDevice *xendev, Error **errp);
typedef void (*XenDeviceUnrealize)(XenDevice *xendev, Error **errp);
@@ -19,6 +26,9 @@ typedef struct XenDeviceClass {
/*< private >*/
DeviceClass parent_class;
/*< public >*/
+ const char *backend;
+ const char *device;
+ XenDeviceGetName get_name;
XenDeviceRealize realize;
XenDeviceUnrealize unrealize;
} XenDeviceClass;
@@ -33,6 +43,8 @@ typedef struct XenDeviceClass {
typedef struct XenBus {
BusState qbus;
+ domid_t backend_id;
+ struct xs_handle *xsh;
} XenBus;
typedef struct XenBusClass {
--
2.11.0
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