...and wire in the dataplane.
This patch adds the remaining code to make the xen-block XenDevice
functional. The parameters that a block frontend expects to find are
populated in the backend xenstore area, and the 'ring-ref' and
'event-channel' values specified in the frontend xenstore area are
mapped/bound and used to set up the dataplane.
Signed-off-by: Paul Durrant <paul.durr...@citrix.com>
---
Cc: Stefano Stabellini <sstabell...@kernel.org>
Cc: Anthony Perard <anthony.per...@citrix.com>
Cc: Kevin Wolf <kw...@redhat.com>
Cc: Max Reitz <mre...@redhat.com>
v3:
- Add missing return statement to xen_block_realize()
- Set device name to 'vbd' now the backend is functional
- Add an unplug handler
- Move backend watch code from subsequent patch since it's now needed
to handle unplug
v2:
- Tidy up header inclusions
- Stop leaking ring_ref on error
- Auto-create drive for CDRom devices
---
hw/block/xen-block.c | 166 ++++++++++++++++++++++++++++++++++++++++
hw/xen/trace-events | 3 +
hw/xen/xen-bus.c | 187 +++++++++++++++++++++++++++++++++++++++------
include/hw/xen/xen-block.h | 9 +++
include/hw/xen/xen-bus.h | 14 +++-
5 files changed, 353 insertions(+), 26 deletions(-)
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index 5932672..f3d21c6 100644
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -10,7 +10,13 @@
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "hw/hw.h"
+#include "hw/xen/xen_common.h"
+#include "hw/block/xen_blkif.h"
#include "hw/xen/xen-block.h"
+#include "sysemu/blockdev.h"
+#include "sysemu/block-backend.h"
+#include "sysemu/iothread.h"
+#include "dataplane/xen-block.h"
#include "trace.h"
static char *xen_block_get_name(XenDevice *xendev, Error **errp)
@@ -28,6 +34,8 @@ static void xen_block_disconnect(XenDevice *xendev, Error
**errp)
XenBlockVdev *vdev = &blockdev->vdev;
trace_xen_block_disconnect(type, vdev->disk, vdev->partition);
+
+ xen_block_dataplane_stop(blockdev->dataplane);
}
static void xen_block_connect(XenDevice *xendev, Error **errp)
@@ -35,8 +43,72 @@ static void xen_block_connect(XenDevice *xendev, Error
**errp)
XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
const char *type = object_get_typename(OBJECT(blockdev));
XenBlockVdev *vdev = &blockdev->vdev;
+ unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol;
+ char *str;
trace_xen_block_connect(type, vdev->disk, vdev->partition);
+
+ if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u",
+ &order) != 1) {
+ nr_ring_ref = 1;
+ ring_ref = g_new(unsigned int, nr_ring_ref);
+
+ if (xen_device_frontend_scanf(xendev, "ring-ref", "%u",
+ &ring_ref[0]) != 1) {
+ error_setg(errp, "failed to read ring-ref");
+ g_free(ring_ref);
+ return;
+ }
+ } else if (order <= blockdev->max_ring_page_order) {
+ unsigned int i;
+
+ nr_ring_ref = 1 << order;
+ ring_ref = g_new(unsigned int, nr_ring_ref);
+
+ for (i = 0; i < nr_ring_ref; i++) {
+ const char *key = g_strdup_printf("ring-ref%u", i);
+
+ if (xen_device_frontend_scanf(xendev, key, "%u",
+ &ring_ref[i]) != 1) {
+ error_setg(errp, "failed to read %s", key);
+ g_free((gpointer)key);
+ g_free(ring_ref);
+ return;
+ }
+
+ g_free((gpointer)key);
+ }
+ } else {
+ error_setg(errp, "invalid ring-page-order (%d)", order);
+ return;
+ }
+
+ if (xen_device_frontend_scanf(xendev, "event-channel", "%u",
+ &event_channel) != 1) {
+ error_setg(errp, "failed to read event-channel");
+ g_free(ring_ref);
+ return;
+ }
+
+ if (xen_device_frontend_scanf(xendev, "protocol", "%ms",
+ &str) != 1) {
+ protocol = BLKIF_PROTOCOL_NATIVE;
+ } else {
+ if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) {
+ protocol = BLKIF_PROTOCOL_X86_32;
+ } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) {
+ protocol = BLKIF_PROTOCOL_X86_64;
+ } else {
+ protocol = BLKIF_PROTOCOL_NATIVE;
+ }
+
+ free(str);
+ }
+
+ xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref,
+ event_channel, protocol, errp);
+
+ g_free(ring_ref);
}
static void xen_block_unrealize(XenDevice *xendev, Error **errp)
@@ -56,6 +128,9 @@ static void xen_block_unrealize(XenDevice *xendev, Error
**errp)
/* Disconnect from the frontend in case this has not already happened */
xen_block_disconnect(xendev, NULL);
+ xen_block_dataplane_destroy(blockdev->dataplane);
+ blockdev->dataplane = NULL;
+
if (blockdev_class->unrealize) {
blockdev_class->unrealize(blockdev, errp);
}
@@ -69,6 +144,7 @@ static void xen_block_realize(XenDevice *xendev, Error
**errp)
const char *type = object_get_typename(OBJECT(blockdev));
XenBlockVdev *vdev = &blockdev->vdev;
Error *local_err = NULL;
+ BlockConf *conf = &blockdev->conf;
if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) {
error_setg(errp, "vdev property not set");
@@ -81,8 +157,62 @@ static void xen_block_realize(XenDevice *xendev, Error
**errp)
blockdev_class->realize(blockdev, &local_err);
if (local_err) {
error_propagate(errp, local_err);
+ return;
}
}
+
+ /*
+ * The blkif protocol does not deal with removable media, so it must
+ * always be present, even for CDRom devices.
+ */
+ assert(conf->blk);
+ if (!blk_is_inserted(conf->blk)) {
+ error_setg(errp, "device needs media, but drive is empty");
+ return;
+ }
+
+ if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY,
+ false, errp)) {
+ return;
+ }
+
+ if (!(blockdev->info & VDISK_CDROM) &&
+ !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) {
+ return;
+ }
+
+ blkconf_blocksizes(conf);
+
+ if (conf->logical_block_size > conf->physical_block_size) {
+ error_setg(
+ errp, "logical_block_size > physical_block_size not supported");
+ return;
+ }
+
+ blk_set_guest_block_size(conf->blk, conf->logical_block_size);
+
+ if (conf->discard_granularity > 0) {
+ xen_device_backend_printf(xendev, "feature-discard", "%u", 1);
+ }
+
+ xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1);
+ xen_device_backend_printf(xendev, "max-ring-page-order", "%u",
+ blockdev->max_ring_page_order);
+ xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
+
+ xen_device_frontend_printf(xendev, "virtual-device", "%lu",
+ vdev->number);
+ xen_device_frontend_printf(xendev, "device-type", "%s",
+ blockdev->device_type);
+
+ xen_device_backend_printf(xendev, "sector-size", "%u",
+ conf->logical_block_size);
+ xen_device_backend_printf(xendev, "sectors", "%lu",
+ blk_getlength(conf->blk) /
+ conf->logical_block_size);
+
+ blockdev->dataplane = xen_block_dataplane_create(xendev, conf,
+ blockdev->iothread);
}
static void xen_block_frontend_changed(XenDevice *xendev,
@@ -331,6 +461,11 @@ const PropertyInfo xen_block_prop_vdev = {
static Property xen_block_props[] = {
DEFINE_PROP("vdev", XenBlockDevice, vdev,
xen_block_prop_vdev, XenBlockVdev),
+ DEFINE_BLOCK_PROPERTIES(XenBlockDevice, conf),
+ DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice,
+ max_ring_page_order, 4),
+ DEFINE_PROP_LINK("iothread", XenBlockDevice, iothread, TYPE_IOTHREAD,
+ IOThread *),
DEFINE_PROP_END_OF_LIST()
};
@@ -339,6 +474,7 @@ static void xen_block_class_init(ObjectClass *class, void
*data)
DeviceClass *dev_class = DEVICE_CLASS(class);
XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class);
+ xendev_class->device = "vbd";
xendev_class->get_name = xen_block_get_name;
xendev_class->realize = xen_block_realize;
xendev_class->frontend_changed = xen_block_frontend_changed;
@@ -363,7 +499,18 @@ static void xen_disk_unrealize(XenBlockDevice *blockdev,
Error **errp)
static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp)
{
+ BlockConf *conf = &blockdev->conf;
+
trace_xen_disk_realize();
+
+ blockdev->device_type = "disk";
+
+ if (!conf->blk) {
+ error_setg(errp, "drive property not set");
+ return;
+ }
+
+ blockdev->info = blk_is_read_only(conf->blk) ? VDISK_READONLY : 0;
}
static void xen_disk_class_init(ObjectClass *class, void *data)
@@ -391,7 +538,26 @@ static void xen_cdrom_unrealize(XenBlockDevice *blockdev,
Error **errp)
static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp)
{
+ BlockConf *conf = &blockdev->conf;
+
trace_xen_cdrom_realize();
+
+ blockdev->device_type = "cdrom";
+
+ if (!conf->blk) {
+ int rc;
+
+ /* Set up an empty drive */
+ conf->blk = blk_new(0, BLK_PERM_ALL);
+
+ rc = blk_attach_dev(conf->blk, DEVICE(blockdev));
+ if (!rc) {
+ error_setg_errno(errp, -rc, "failed to create drive");
+ return;
+ }
+ }
+
+ blockdev->info = VDISK_READONLY | VDISK_CDROM;
}
static void xen_cdrom_class_init(ObjectClass *class, void *data)
diff --git a/hw/xen/trace-events b/hw/xen/trace-events
index 22055b5..d4651bd 100644
--- a/hw/xen/trace-events
+++ b/hw/xen/trace-events
@@ -22,8 +22,11 @@ xen_bus_watch(const char *token) "token: %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_backend_online(const char *type, char *name, bool online) "type: %s
name: %s -> %u"
+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"
# include/hw/xen/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 9443f27..a22aa49 100644
--- a/hw/xen/xen-bus.c
+++ b/hw/xen/xen-bus.c
@@ -48,6 +48,54 @@ static char *xen_device_get_frontend_path(XenDevice *xendev)
xendev->frontend_id, device, xendev->name);
}
+static void xen_device_unplug(XenDevice *xendev, Error **errp)
+{
+ XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
+ const char *type = object_get_typename(OBJECT(xendev));
+ Error *local_err = NULL;
+ xs_transaction_t tid;
+
+ trace_xen_device_unplug(type, xendev->name);
+
+ /* Mimic the way the Xen toolstack does an unplug */
+again:
+ tid = xs_transaction_start(xenbus->xsh);
+ if (tid == XBT_NULL) {
+ error_setg_errno(errp, errno, "failed xs_transaction_start");
+ return;
+ }
+
+ xs_node_printf(xenbus->xsh, tid, xendev->backend_path, "online",
+ &local_err, "%u", 0);
+ if (local_err) {
+ goto abort;
+ }
+
+ xs_node_printf(xenbus->xsh, tid, xendev->backend_path, "state",
+ &local_err, "%u", XenbusStateClosing);
+ if (local_err) {
+ goto abort;
+ }
+
+ if (!xs_transaction_end(xenbus->xsh, tid, false)) {
+ if (errno == EAGAIN) {
+ goto again;
+ }
+
+ error_setg_errno(errp, errno, "failed xs_transaction_end");
+ }
+
+ return;
+
+abort:
+ /*
+ * We only abort if there is already a failure so ignore any error
+ * from ending the transaction.
+ */
+ xs_transaction_end(xenbus->xsh, tid, true);
+ error_propagate(errp, local_err);
+}
+
static void xen_bus_print_dev(Monitor *mon, DeviceState *dev, int indent)
{
XenDevice *xendev = XEN_DEVICE(dev);
@@ -208,14 +256,26 @@ fail:
xen_bus_unrealize(bus, &error_abort);
}
+static void xen_bus_unplug_request(HotplugHandler *hotplug,
+ DeviceState *dev,
+ Error **errp)
+{
+ XenDevice *xendev = XEN_DEVICE(dev);
+
+ xen_device_unplug(xendev, errp);
+}
+
static void xen_bus_class_init(ObjectClass *class, void *data)
{
BusClass *bus_class = BUS_CLASS(class);
+ HotplugHandlerClass *hotplug_class = HOTPLUG_HANDLER_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;
+
+ hotplug_class->unplug_request = xen_bus_unplug_request;
}
static const TypeInfo xen_bus_type_info = {
@@ -230,8 +290,8 @@ static const TypeInfo xen_bus_type_info = {
},
};
-static void xen_device_backend_printf(XenDevice *xendev, const char *key,
- const char *fmt, ...)
+void xen_device_backend_printf(XenDevice *xendev, const char *key,
+ const char *fmt, ...)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
Error *local_err = NULL;
@@ -287,6 +347,70 @@ enum xenbus_state xen_device_backend_get_state(XenDevice
*xendev)
return xendev->backend_state;
}
+static void xen_device_backend_set_online(XenDevice *xendev, bool online)
+{
+ const char *type = object_get_typename(OBJECT(xendev));
+
+ if (xendev->backend_online == online) {
+ return;
+ }
+
+ trace_xen_device_backend_online(type, xendev->name, online);
+
+ xendev->backend_online = online;
+ xen_device_backend_printf(xendev, "online", "%u", online);
+}
+
+static void xen_device_backend_changed(void *opaque)
+{
+ XenDevice *xendev = opaque;
+ const char *type = object_get_typename(OBJECT(xendev));
+ enum xenbus_state state;
+ unsigned int online;
+
+ trace_xen_device_backend_changed(type, xendev->name);
+
+ if (xen_device_backend_scanf(xendev, "state", "%u", &state) != 1) {
+ state = XenbusStateUnknown;
+ }
+
+ xen_device_backend_set_state(xendev, state);
+
+ if (xen_device_backend_scanf(xendev, "online", "%u", &online) != 1) {
+ online = 0;
+ }
+
+ xen_device_backend_set_online(xendev, !!online);
+
+ /*
+ * If the toolstack (or unplug request callback) has set the backend
+ * state to Closing, but there is no active frontend (i.e. the
+ * state is not Connected) then set the backend state to Closed.
+ */
+ if (xendev->backend_state == XenbusStateClosing &&
+ xendev->frontend_state != XenbusStateConnected) {
+ xen_device_backend_set_state(xendev, XenbusStateClosed);
+ }
+
+ /*
+ * If a backend is still 'online' then its state should be cycled
+ * back round to InitWait in order for a new frontend instance to
+ * connect. This may happen when, for example, a frontend driver is
+ * re-installed or updated.
+ * If a backend is not 'online' then the device should be destroyed.
+ */
+ if (xendev->backend_online &&
+ xendev->backend_state == XenbusStateClosed) {
+ xen_device_backend_set_state(xendev, XenbusStateInitWait);
+ } else if (!xendev->backend_online &&
+ (xendev->backend_state == XenbusStateClosed ||
+ xendev->backend_state == XenbusStateInitialising ||
+ xendev->backend_state == XenbusStateInitWait ||
+ xendev->backend_state == XenbusStateUnknown)) {
+ object_unparent(OBJECT(xendev));
+ }
+}
+
static void xen_device_backend_create(XenDevice *xendev, Error **errp)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
@@ -307,6 +431,27 @@ static void xen_device_backend_create(XenDevice *xendev,
Error **errp)
if (local_err) {
error_propagate_prepend(errp, local_err,
"failed to create backend: ");
+ return;
+ }
+
+ xendev->backend_state_watch =
+ xen_bus_add_watch(xenbus, xendev->backend_path,
+ "state", xen_device_backend_changed,
+ xendev, &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err,
+ "failed to watch backend state: ");
+ return;
+ }
+
+ xendev->backend_online_watch =
+ xen_bus_add_watch(xenbus, xendev->backend_path,
+ "online", xen_device_backend_changed,
+ xendev, &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err,
+ "failed to watch backend online: ");
+ return;
}
}
@@ -315,6 +460,16 @@ static void xen_device_backend_destroy(XenDevice *xendev)
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
Error *local_err = NULL;
+ if (xendev->backend_online_watch) {
+ xen_bus_remove_watch(xenbus, 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);
+ xendev->backend_state_watch = NULL;
+ }
+
if (!xendev->backend_path) {
return;
}
@@ -331,8 +486,8 @@ static void xen_device_backend_destroy(XenDevice *xendev)
}
}
-static void xen_device_frontend_printf(XenDevice *xendev, const char *key,
- const char *fmt, ...)
+void xen_device_frontend_printf(XenDevice *xendev, const char *key,
+ const char *fmt, ...)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
Error *local_err = NULL;
@@ -350,8 +505,8 @@ static void xen_device_frontend_printf(XenDevice *xendev,
const char *key,
}
}
-static int xen_device_frontend_scanf(XenDevice *xendev, const char *key,
- const char *fmt, ...)
+int xen_device_frontend_scanf(XenDevice *xendev, const char *key,
+ const char *fmt, ...)
{
XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev)));
va_list ap;
@@ -407,24 +562,6 @@ static void xen_device_frontend_changed(void *opaque)
error_reportf_err(local_err, "frontend change error: ");
}
}
-
- /*
- * If a backend is still 'online' then its state should be cycled
- * back round to InitWait in order for a new frontend instance to
- * connect. This may happen when, for example, a frontend driver is
- * re-installed or updated.
- */
- if (xendev->backend_state == XenbusStateClosed) {
- unsigned int online;
-
- if (xen_device_backend_scanf(xendev, "online", "%u", &online) != 1) {
- online = 0;
- }
-
- if (online) {
- xen_device_backend_set_state(xendev, XenbusStateInitWait);
- }
- }
}
static void xen_device_frontend_create(XenDevice *xendev, Error **errp)
@@ -822,9 +959,9 @@ static void xen_device_realize(DeviceState *dev, Error
**errp)
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_online(xendev, true);
xen_device_backend_set_state(xendev, XenbusStateInitWait);
xen_device_frontend_printf(xendev, "backend", "%s",
diff --git a/include/hw/xen/xen-block.h b/include/hw/xen/xen-block.h
index 067932a..37ed8a6 100644
--- a/include/hw/xen/xen-block.h
+++ b/include/hw/xen/xen-block.h
@@ -9,6 +9,9 @@
#define HW_XEN_BLOCK_H
#include "hw/xen/xen-bus.h"
+#include "hw/block/block.h"
+#include "hw/block/dataplane/xen-block.h"
+#include "sysemu/iothread.h"
typedef enum XenBlockVdevType {
XEN_BLOCK_VDEV_TYPE_INVALID,
@@ -29,6 +32,12 @@ typedef struct XenBlockVdev {
typedef struct XenBlockDevice {
XenDevice xendev;
XenBlockVdev vdev;
+ BlockConf conf;
+ const char *device_type;
+ unsigned int info;
+ unsigned int max_ring_page_order;
+ IOThread *iothread;
+ XenBlockDataPlane *dataplane;
} XenBlockDevice;
typedef void (*XenBlockDeviceRealize)(XenBlockDevice *blockdev, Error **errp);
diff --git a/include/hw/xen/xen-bus.h b/include/hw/xen/xen-bus.h
index f83a95c..0834cb3 100644
--- a/include/hw/xen/xen-bus.h
+++ b/include/hw/xen/xen-bus.h
@@ -23,7 +23,9 @@ typedef struct XenDevice {
char *backend_path, *frontend_path;
enum xenbus_state backend_state, frontend_state;
Notifier exit;
- XenWatch *frontend_state_watch;
+ XenWatch *backend_state_watch, *frontend_state_watch;
+ bool backend_online;
+ XenWatch *backend_online_watch;
xengnttab_handle *xgth;
bool feature_grant_copy;
xenevtchn_handle *xeh;
@@ -84,6 +86,16 @@ void xen_device_backend_set_state(XenDevice *xendev,
enum xenbus_state state);
enum xenbus_state xen_device_backend_get_state(XenDevice *xendev);
+void xen_device_backend_printf(XenDevice *xendev, const char *key,
+ const char *fmt, ...)
+ GCC_FMT_ATTR(3, 4);
+void xen_device_frontend_printf(XenDevice *xendev, const char *key,
+ const char *fmt, ...)
+ GCC_FMT_ATTR(3, 4);
+
+int xen_device_frontend_scanf(XenDevice *xendev, const char *key,
+ const char *fmt, ...);
+
void xen_device_set_max_grant_refs(XenDevice *xendev, unsigned int nr_refs,
Error **errp);
void *xen_device_map_grant_refs(XenDevice *xendev, uint32_t *refs,
--
2.1.4
