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[Qemu-block] [PATCH v9 16/18] xen: automatically create XenBlockDevice-s
From: |
Paul Durrant |
Subject: |
[Qemu-block] [PATCH v9 16/18] xen: automatically create XenBlockDevice-s |
Date: |
Tue, 8 Jan 2019 14:49:01 +0000 |
This patch adds create and destroy function for XenBlockDevice-s so that
they can be created automatically when the Xen toolstack instantiates a new
PV backend via xenstore. When the XenBlockDevice is created this way it is
also necessary to create a 'drive' which matches the configuration that the
Xen toolstack has written into xenstore. This is done by formulating the
parameters necessary for each 'blockdev' layer of the drive and then using
qmp_blockdev_add() to create the layers. Also, for compatibility with the
legacy 'xen_disk' implementation, an iothread is automatically created for
the new XenBlockDevice. This, like the driver layers, will be destroyed
after the XenBlockDevice is unrealized.
The legacy backend scan for 'qdisk' is removed by this patch, which makes
the 'xen_disk' code is redundant. The code will be removed by a subsequent
patch.
Signed-off-by: Paul Durrant <address@hidden>
Signed-off-by: Anthony Perard <address@hidden>
---
Cc: Kevin Wolf <address@hidden>
Cc: Max Reitz <address@hidden>
Cc: Stefano Stabellini <address@hidden>
v9:
- Squash the layers with patch from Anthony
v8:
- Add 'raw' image layer for raw images
v7:
- Don't use qobject_input_visitor_new_flat_confused()
v5:
- Extensively re-worked to avoid using drive_new() and use
qmp_blockdev_add() instead
- Also use qmp_object_add() for IOThread
- Dropped Anthony's R-b because of the code changes
v2:
- Get rid of error_abort
- Don't use qdev_init_nofail()
- Explain why file locking needs to be off
---
hw/block/trace-events | 4 +
hw/block/xen-block.c | 374 ++++++++++++++++++++++++++++++++++++
hw/xen/xen-legacy-backend.c | 1 -
include/hw/xen/xen-block.h | 12 ++
4 files changed, 390 insertions(+), 1 deletion(-)
diff --git a/hw/block/trace-events b/hw/block/trace-events
index 89e258319c..55e5a5500c 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -137,3 +137,7 @@ xen_disk_realize(void) ""
xen_disk_unrealize(void) ""
xen_cdrom_realize(void) ""
xen_cdrom_unrealize(void) ""
+xen_block_blockdev_add(char *str) "%s"
+xen_block_blockdev_del(const char *node_name) "%s"
+xen_block_device_create(unsigned int number) "%u"
+xen_block_device_destroy(unsigned int number) "%u"
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index a7c37c185a..c6ec1d9543 100644
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -7,12 +7,20 @@
#include "qemu/osdep.h"
#include "qemu/cutils.h"
+#include "qemu/option.h"
#include "qapi/error.h"
+#include "qapi/qapi-commands-block-core.h"
+#include "qapi/qapi-commands-misc.h"
+#include "qapi/qapi-visit-block-core.h"
+#include "qapi/qobject-input-visitor.h"
#include "qapi/visitor.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qstring.h"
#include "hw/hw.h"
#include "hw/xen/xen_common.h"
#include "hw/block/xen_blkif.h"
#include "hw/xen/xen-block.h"
+#include "hw/xen/xen-backend.h"
#include "sysemu/blockdev.h"
#include "sysemu/block-backend.h"
#include "sysemu/iothread.h"
@@ -474,6 +482,7 @@ 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->backend = "qdisk";
xendev_class->device = "vbd";
xendev_class->get_name = xen_block_get_name;
xendev_class->realize = xen_block_realize;
@@ -586,3 +595,368 @@ static void xen_block_register_types(void)
}
type_init(xen_block_register_types)
+
+static void xen_block_blockdev_del(const char *node_name, Error **errp)
+{
+ trace_xen_block_blockdev_del(node_name);
+
+ qmp_blockdev_del(node_name, errp);
+}
+
+static char *xen_block_blockdev_add(const char *id, QDict *qdict,
+ Error **errp)
+{
+ const char *driver = qdict_get_try_str(qdict, "driver");
+ BlockdevOptions *options = NULL;
+ Error *local_err = NULL;
+ char *node_name;
+ Visitor *v;
+
+ if (!driver) {
+ error_setg(errp, "no 'driver' parameter");
+ return NULL;
+ }
+
+ node_name = g_strdup_printf("%s-%s", id, driver);
+ qdict_put_str(qdict, "node-name", node_name);
+
+ trace_xen_block_blockdev_add(node_name);
+
+ v = qobject_input_visitor_new(QOBJECT(qdict));
+ visit_type_BlockdevOptions(v, NULL, &options, &local_err);
+ visit_free(v);
+
+ if (local_err) {
+ error_propagate(errp, local_err);
+ goto fail;
+ }
+
+ qmp_blockdev_add(options, &local_err);
+
+ if (local_err) {
+ error_propagate(errp, local_err);
+ goto fail;
+ }
+
+ qapi_free_BlockdevOptions(options);
+
+ return node_name;
+
+fail:
+ if (options) {
+ qapi_free_BlockdevOptions(options);
+ }
+ g_free(node_name);
+
+ return NULL;
+}
+
+static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp)
+{
+ char *node_name = drive->node_name;
+
+ if (node_name) {
+ Error *local_err = NULL;
+
+ xen_block_blockdev_del(node_name, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+ g_free(node_name);
+ drive->node_name = NULL;
+ }
+ g_free(drive->id);
+ g_free(drive);
+}
+
+static XenBlockDrive *xen_block_drive_create(const char *id,
+ const char *device_type,
+ QDict *opts, Error **errp)
+{
+ const char *params = qdict_get_try_str(opts, "params");
+ const char *mode = qdict_get_try_str(opts, "mode");
+ const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe");
+ const char *discard_enable = qdict_get_try_str(opts, "discard-enable");
+ char *driver = NULL;
+ char *filename = NULL;
+ XenBlockDrive *drive = NULL;
+ Error *local_err = NULL;
+ QDict *file_layer;
+ QDict *driver_layer;
+
+ if (params) {
+ char **v = g_strsplit(params, ":", 2);
+
+ if (v[1] == NULL) {
+ filename = g_strdup(v[0]);
+ driver = g_strdup("raw");
+ } else {
+ if (strcmp(v[0], "aio") == 0) {
+ driver = g_strdup("raw");
+ } else if (strcmp(v[0], "vhd") == 0) {
+ driver = g_strdup("vpc");
+ } else {
+ driver = g_strdup(v[0]);
+ }
+ filename = g_strdup(v[1]);
+ }
+
+ g_strfreev(v);
+ }
+
+ if (!filename) {
+ error_setg(errp, "no filename");
+ goto done;
+ }
+ assert(driver);
+
+ drive = g_new0(XenBlockDrive, 1);
+ drive->id = g_strdup(id);
+
+ file_layer = qdict_new();
+
+ qdict_put_str(file_layer, "driver", "file");
+ qdict_put_str(file_layer, "filename", filename);
+
+ if (mode && *mode != 'w') {
+ qdict_put_bool(file_layer, "read-only", true);
+ }
+
+ if (direct_io_safe) {
+ unsigned long value;
+
+ if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) {
+ QDict *cache_qdict = qdict_new();
+
+ qdict_put_bool(cache_qdict, "direct", true);
+ qdict_put_obj(file_layer, "cache", QOBJECT(cache_qdict));
+
+ qdict_put_str(file_layer, "aio", "native");
+ }
+ }
+
+ if (discard_enable) {
+ unsigned long value;
+
+ if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) {
+ qdict_put_str(file_layer, "discard", "unmap");
+ }
+ }
+
+ /*
+ * It is necessary to turn file locking off as an emulated device
+ * may have already opened the same image file.
+ */
+ qdict_put_str(file_layer, "locking", "off");
+
+ driver_layer = qdict_new();
+
+ qdict_put_str(driver_layer, "driver", driver);
+ qdict_put_obj(driver_layer, "file", QOBJECT(file_layer));
+
+ g_assert(!drive->node_name);
+ drive->node_name = xen_block_blockdev_add(drive->id, driver_layer,
+ &local_err);
+
+done:
+ g_free(driver);
+ g_free(filename);
+
+ if (local_err) {
+ xen_block_drive_destroy(drive, NULL);
+ return NULL;
+ }
+
+ return drive;
+}
+
+static const char *xen_block_drive_get_node_name(XenBlockDrive *drive)
+{
+ return drive->node_name ? drive->node_name : "";
+}
+
+static void xen_block_iothread_destroy(XenBlockIOThread *iothread,
+ Error **errp)
+{
+ qmp_object_del(iothread->id, errp);
+
+ g_free(iothread->id);
+ g_free(iothread);
+}
+
+static XenBlockIOThread *xen_block_iothread_create(const char *id,
+ Error **errp)
+{
+ XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1);
+ Error *local_err = NULL;
+
+ iothread->id = g_strdup(id);
+
+ qmp_object_add(TYPE_IOTHREAD, id, false, NULL, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+
+ g_free(iothread->id);
+ g_free(iothread);
+ return NULL;
+ }
+
+ return iothread;
+}
+
+static void xen_block_device_create(XenBackendInstance *backend,
+ QDict *opts, Error **errp)
+{
+ XenBus *xenbus = xen_backend_get_bus(backend);
+ const char *name = xen_backend_get_name(backend);
+ unsigned long number;
+ const char *vdev, *device_type;
+ XenBlockDrive *drive = NULL;
+ XenBlockIOThread *iothread = NULL;
+ XenDevice *xendev = NULL;
+ Error *local_err = NULL;
+ const char *type;
+ XenBlockDevice *blockdev;
+
+ if (qemu_strtoul(name, NULL, 10, &number)) {
+ error_setg(errp, "failed to parse name '%s'", name);
+ goto fail;
+ }
+
+ trace_xen_block_device_create(number);
+
+ vdev = qdict_get_try_str(opts, "dev");
+ if (!vdev) {
+ error_setg(errp, "no dev parameter");
+ goto fail;
+ }
+
+ device_type = qdict_get_try_str(opts, "device-type");
+ if (!device_type) {
+ error_setg(errp, "no device-type parameter");
+ goto fail;
+ }
+
+ if (!strcmp(device_type, "disk")) {
+ type = TYPE_XEN_DISK_DEVICE;
+ } else if (!strcmp(device_type, "cdrom")) {
+ type = TYPE_XEN_CDROM_DEVICE;
+ } else {
+ error_setg(errp, "invalid device-type parameter '%s'", device_type);
+ goto fail;
+ }
+
+ drive = xen_block_drive_create(vdev, device_type, opts, &local_err);
+ if (!drive) {
+ error_propagate_prepend(errp, local_err, "failed to create drive: ");
+ goto fail;
+ }
+
+ iothread = xen_block_iothread_create(vdev, &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err,
+ "failed to create iothread: ");
+ goto fail;
+ }
+
+ xendev = XEN_DEVICE(qdev_create(BUS(xenbus), type));
+ blockdev = XEN_BLOCK_DEVICE(xendev);
+
+ object_property_set_str(OBJECT(xendev), vdev, "vdev", &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err, "failed to set 'vdev': ");
+ goto fail;
+ }
+
+ object_property_set_str(OBJECT(xendev),
+ xen_block_drive_get_node_name(drive), "drive",
+ &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err, "failed to set 'drive': ");
+ goto fail;
+ }
+
+ object_property_set_str(OBJECT(xendev), iothread->id, "iothread",
+ &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err,
+ "failed to set 'iothread': ");
+ goto fail;
+ }
+
+ blockdev->iothread = iothread;
+ blockdev->drive = drive;
+
+ object_property_set_bool(OBJECT(xendev), true, "realized", &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err,
+ "realization of device %s failed: ",
+ type);
+ goto fail;
+ }
+
+ xen_backend_set_device(backend, xendev);
+ return;
+
+fail:
+ if (xendev) {
+ object_unparent(OBJECT(xendev));
+ }
+
+ if (iothread) {
+ xen_block_iothread_destroy(iothread, NULL);
+ }
+
+ if (drive) {
+ xen_block_drive_destroy(drive, NULL);
+ }
+}
+
+static void xen_block_device_destroy(XenBackendInstance *backend,
+ Error **errp)
+{
+ XenDevice *xendev = xen_backend_get_device(backend);
+ XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev);
+ XenBlockVdev *vdev = &blockdev->props.vdev;
+ XenBlockDrive *drive = blockdev->drive;
+ XenBlockIOThread *iothread = blockdev->iothread;
+
+ trace_xen_block_device_destroy(vdev->number);
+
+ object_unparent(OBJECT(xendev));
+
+ if (iothread) {
+ Error *local_err = NULL;
+
+ xen_block_iothread_destroy(iothread, &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err,
+ "failed to destroy iothread: ");
+ return;
+ }
+ }
+
+ if (drive) {
+ Error *local_err = NULL;
+
+ xen_block_drive_destroy(drive, &local_err);
+ if (local_err) {
+ error_propagate_prepend(errp, local_err,
+ "failed to destroy drive: ");
+ }
+ }
+}
+
+static const XenBackendInfo xen_block_backend_info = {
+ .type = "qdisk",
+ .create = xen_block_device_create,
+ .destroy = xen_block_device_destroy,
+};
+
+static void xen_block_register_backend(void)
+{
+ xen_backend_register(&xen_block_backend_info);
+}
+
+xen_backend_init(xen_block_register_backend);
diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c
index 41419763c8..36fd1e9b09 100644
--- a/hw/xen/xen-legacy-backend.c
+++ b/hw/xen/xen-legacy-backend.c
@@ -753,7 +753,6 @@ void xen_be_register_common(void)
xen_be_register("console", &xen_console_ops);
xen_be_register("vkbd", &xen_kbdmouse_ops);
- xen_be_register("qdisk", &xen_blkdev_ops);
#ifdef CONFIG_VIRTFS
xen_be_register("9pfs", &xen_9pfs_ops);
#endif
diff --git a/include/hw/xen/xen-block.h b/include/hw/xen/xen-block.h
index c4223f9be1..11d351b4b3 100644
--- a/include/hw/xen/xen-block.h
+++ b/include/hw/xen/xen-block.h
@@ -29,6 +29,7 @@ typedef struct XenBlockVdev {
unsigned long number;
} XenBlockVdev;
+
typedef struct XenBlockProperties {
XenBlockVdev vdev;
BlockConf conf;
@@ -36,12 +37,23 @@ typedef struct XenBlockProperties {
IOThread *iothread;
} XenBlockProperties;
+typedef struct XenBlockDrive {
+ char *id;
+ char *node_name;
+} XenBlockDrive;
+
+typedef struct XenBlockIOThread {
+ char *id;
+} XenBlockIOThread;
+
typedef struct XenBlockDevice {
XenDevice xendev;
XenBlockProperties props;
const char *device_type;
unsigned int info;
XenBlockDataPlane *dataplane;
+ XenBlockDrive *drive;
+ XenBlockIOThread *iothread;
} XenBlockDevice;
typedef void (*XenBlockDeviceRealize)(XenBlockDevice *blockdev, Error **errp);
--
2.20.1.2.gb21ebb6
- [Qemu-block] [PATCH v9 02/18] xen: introduce new 'XenBus' and 'XenDevice' object hierarchy, (continued)
- [Qemu-block] [PATCH v9 02/18] xen: introduce new 'XenBus' and 'XenDevice' object hierarchy, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 04/18] xen: create xenstore areas for XenDevice-s, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 08/18] xen: duplicate xen_disk.c as basis of dataplane/xen-block.c, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 09/18] xen: remove unnecessary code from dataplane/xen-block.c, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 01/18] xen: re-name XenDevice to XenLegacyDevice..., Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 12/18] xen: remove 'ioreq' struct/varable/field names from dataplane/xen-block.c, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 14/18] xen: add implementations of xen-block connect and disconnect functions..., Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 18/18] xen: remove the legacy 'xen_disk' backend, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 13/18] xen: purge 'blk' and 'ioreq' from function names in dataplane/xen-block.c, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 17/18] MAINTAINERS: add myself as a Xen maintainer, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 16/18] xen: automatically create XenBlockDevice-s,
Paul Durrant <=
- [Qemu-block] [PATCH v9 11/18] xen: remove 'XenBlkDev' and 'blkdev' names from dataplane/xen-block, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 10/18] xen: add header and build dataplane/xen-block.c, Paul Durrant, 2019/01/08
- [Qemu-block] [PATCH v9 15/18] xen: add a mechanism to automatically create XenDevice-s..., Paul Durrant, 2019/01/08