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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH 2/2] libxl: Enable stubdom cdrom changing
To change the cd-rom medium, libxl will:
- QMP eject the medium from QEMU
- block-detach the old PV disk
- block-attach the new PV disk
- QMP change the medium to the new PV disk by fdset-id
The QMP code is reused, and remove and attach are implemented here.
The stubdom must internally handle adding /dev/xvdc to the appropriate
fdset. libxl in dom0 doesn't see the result of adding to the fdset as
that is internal to the stubdom, so a delay and retries are added to
around calling cdrom_insert_addfd_cb().
Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
---
docs/misc/stubdom.txt | 16 ++
tools/libs/light/libxl_disk.c | 299 ++++++++++++++++++++++++++++++----
2 files changed, 285 insertions(+), 30 deletions(-)
diff --git a/docs/misc/stubdom.txt b/docs/misc/stubdom.txt
index c717a95d17..1b2380ae8f 100644
--- a/docs/misc/stubdom.txt
+++ b/docs/misc/stubdom.txt
@@ -127,6 +127,22 @@ Limitations:
- at most 26 emulated disks are supported (more are still available as PV
disks)
- graphics output (VNC/SDL/Spice) not supported
+CD-ROM changing:
+
+To change the CD-ROM medium, libxl will:
+ - QMP eject the medium from QEMU
+ - block-detach the old PV disk
+ - block-attach the new PV disk
+ - QMP change the medium to the new PV disk by fdset-id
+
+The QMP change insert uses fdset-id STUBDOM_FDSET_CD + $disk - 'a'.
+That is, hda -> 'a', so
+STUBDOM_FDSET_CD + 'a' - 'a' = STUBDOM_FDSET_CD.
+For hdc:
+STUBDOM_FDSET_CD + 'c' - 'a' = STUBDOM_FDSET_CD + 2.
+
+The stubdom must internally handle adding /dev/xvdc to the appropriate
+fdset.
PV-GRUB
=======
diff --git a/tools/libs/light/libxl_disk.c b/tools/libs/light/libxl_disk.c
index d1f84ef404..c67da510f2 100644
--- a/tools/libs/light/libxl_disk.c
+++ b/tools/libs/light/libxl_disk.c
@@ -790,25 +790,46 @@ int libxl_device_disk_getinfo(libxl_ctx *ctx, uint32_t
domid,
typedef struct {
libxl__ao *ao;
+ libxl__ao_device aodev;
+ libxl__ao_device aodev_del;
libxl_domid domid;
+ libxl_domid disk_domid;
libxl_device_disk *disk;
libxl_device_disk disk_saved;
libxl__ev_slowlock qmp_lock;
int dm_ver;
libxl__ev_time time;
+ libxl__ev_time timeout_retry;
libxl__ev_qmp qmp;
+ int retries;
+ int stubdom_fdset;
} libxl__cdrom_insert_state;
static void cdrom_insert_lock_acquired(libxl__egc *, libxl__ev_slowlock *,
int rc);
static void cdrom_insert_qmp_connected(libxl__egc *, libxl__ev_qmp *,
const libxl__json_object *, int rc);
+static void cdrom_insert_stubdom_removefd(libxl__egc *egc, libxl__ev_qmp *qmp,
+ const libxl__json_object *response,
+ int rc);
+static void cdrom_insert_stubdom_ejected(libxl__egc *egc, libxl__ev_qmp *,
+ const libxl__json_object *, int rc);
+static void cdrom_insert_stubdom_disk_ejected_aocomplete(libxl__egc *egc,
+ libxl__ao_device
*aodev);
+static void cdrom_insert_stubdom_disk_ejected(libxl__egc *egc, libxl__ev_qmp *,
+ const libxl__json_object *,
+ int rc);
+static void cdrom_insert_ejected_aodevcb(libxl__egc *egc,
+ libxl__ao_device *aodev);
static void cdrom_insert_ejected(libxl__egc *egc, libxl__ev_qmp *,
const libxl__json_object *, int rc);
static void cdrom_insert_addfd_cb(libxl__egc *egc, libxl__ev_qmp *,
const libxl__json_object *, int rc);
static void cdrom_insert_inserted(libxl__egc *egc, libxl__ev_qmp *,
const libxl__json_object *, int rc);
+static void cdrom_insert_addfd_retry(libxl__egc *egc, libxl__ev_time *ev,
+ const struct timeval *requested_abs,
+ int rc);
static void cdrom_insert_timout(libxl__egc *egc, libxl__ev_time *ev,
const struct timeval *requested_abs,
int rc);
@@ -824,6 +845,7 @@ int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid,
libxl_device_disk *disk,
libxl_device_disk *disks = NULL;
int rc;
libxl__cdrom_insert_state *cis;
+ libxl_domid stubdomid;
GCNEW(cis);
cis->ao = ao;
@@ -835,6 +857,8 @@ int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid,
libxl_device_disk *disk,
cis->qmp_lock.ao = ao;
cis->qmp_lock.domid = domid;
libxl__ev_time_init(&cis->time);
+ libxl__ev_time_init(&cis->timeout_retry);
+ cis->retries = 0;
libxl__ev_qmp_init(&cis->qmp);
cis->qmp.ao = ao;
cis->qmp.domid = domid;
@@ -851,12 +875,6 @@ int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid,
libxl_device_disk *disk,
goto out;
}
- if (libxl_get_stubdom_id(ctx, domid) != 0) {
- LOGD(ERROR, domid, "cdrom-insert doesn't work for stub domains");
- rc = ERROR_INVAL;
- goto out;
- }
-
cis->dm_ver = libxl__device_model_version_running(gc, domid);
if (cis->dm_ver == -1) {
LOGD(ERROR, domid, "Cannot determine device model version");
@@ -864,7 +882,14 @@ int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid,
libxl_device_disk *disk,
goto out;
}
- disks = libxl__device_list(gc, &libxl__disk_devtype, domid, &num);
+ stubdomid = libxl_get_stubdom_id(CTX, cis->domid);
+ if (stubdomid == 0) {
+ cis->disk_domid = domid;
+ } else {
+ cis->disk_domid = stubdomid;
+ }
+
+ disks = libxl__device_list(gc, &libxl__disk_devtype, cis->disk_domid,
&num);
for (i = 0; i < num; i++) {
if (disks[i].is_cdrom && !strcmp(disk->vdev, disks[i].vdev))
{
@@ -879,7 +904,7 @@ int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid,
libxl_device_disk *disk,
goto out;
}
- rc = libxl__device_disk_setdefault(gc, domid, disk, false);
+ rc = libxl__device_disk_setdefault(gc, cis->disk_domid, disk, false);
if (rc) goto out;
if (!disk->pdev_path) {
@@ -887,6 +912,18 @@ int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid,
libxl_device_disk *disk,
disk->format = LIBXL_DISK_FORMAT_EMPTY;
}
+#define STUBDOM_FDSET_CD 8000
+ if (strncmp(disk->vdev, "hd", 2) == 0) {
+ cis->stubdom_fdset = STUBDOM_FDSET_CD + disk->vdev[2] - 'a';
+ } else if (strncmp(disk->vdev, "xvd", 3) == 0) {
+ cis->stubdom_fdset = STUBDOM_FDSET_CD + disk->vdev[3] - 'a';
+ } else {
+ LOGD(ERROR, cis->domid, "disk->vdev \"%s\" isn't hdX or xvdY",
+ disk->vdev);
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
out:
libxl__device_list_free(&libxl__disk_devtype, disks, num);
if (rc) {
@@ -905,6 +942,7 @@ static void cdrom_insert_lock_acquired(libxl__egc *egc,
libxl__cdrom_insert_state *cis = CONTAINER_OF(lock, *cis, qmp_lock);
STATE_AO_GC(cis->ao);
+ LOGD(DEBUG, cis->domid, "rc=%d", rc);
if (rc) goto out;
rc = libxl__ev_time_register_rel(ao, &cis->time,
@@ -953,7 +991,12 @@ static void cdrom_insert_qmp_connected(libxl__egc *egc,
libxl__ev_qmp *qmp,
QMP_PARAMETERS_SPRINTF(&args, "id", "ide-%i", devid);
else
QMP_PARAMETERS_SPRINTF(&args, "device", "ide-%i", devid);
- qmp->callback = cdrom_insert_ejected;
+
+ if (libxl_get_stubdom_id(CTX, cis->domid))
+ qmp->callback = cdrom_insert_stubdom_removefd;
+ else
+ qmp->callback = cdrom_insert_ejected;
+
rc = libxl__ev_qmp_send(egc, qmp, "eject", args);
if (rc) goto out;
return;
@@ -961,6 +1004,147 @@ out:
cdrom_insert_done(egc, cis, rc); /* must be last */
}
+static void cdrom_insert_stubdom_removefd(libxl__egc *egc, libxl__ev_qmp *qmp,
+ const libxl__json_object *response,
+ int rc)
+{
+ libxl__cdrom_insert_state *cis = CONTAINER_OF(qmp, *cis, qmp);
+ STATE_AO_GC(cis->ao);
+
+ if (rc) goto out;
+
+ /* Only called for qemu-xen/linux stubdom. */
+ assert(cis->dm_ver == LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN);
+ libxl__json_object *args = NULL;
+
+ libxl__qmp_param_add_integer(gc, &args, "fdset-id", cis->stubdom_fdset);
+
+ cis->qmp.callback = cdrom_insert_stubdom_ejected;
+
+ rc = libxl__ev_qmp_send(egc, &cis->qmp, "remove-fd", args);
+ if (rc) goto out;
+
+ return;
+
+out:
+ cdrom_insert_done(egc, cis, rc); /* must be last */
+}
+
+static void cdrom_insert_stubdom_ejected(libxl__egc *egc, libxl__ev_qmp *qmp,
+ const libxl__json_object *response,
+ int rc)
+{
+ libxl__cdrom_insert_state *cis = CONTAINER_OF(qmp, *cis, qmp);
+ libxl__device *device;
+ STATE_AO_GC(cis->ao);
+ domid_t stubdomid = libxl_get_stubdom_id(CTX, cis->domid);
+
+ LOGD(DEBUG, cis->domid, "rc=%d", rc);
+ /* cis->stubdom_fdset is initially empty, so remove-fd fails the first
+ * call with:
+ * {"error": {"class": "GenericError",
+ * "desc": "File descriptor named 'fdset-id:8675' not found"}}
+ * Carry on in that case. */
+ if (rc && rc != ERROR_QMP_GENERIC_ERROR) goto out;
+
+ GCNEW(device);
+ rc = libxl__device_from_disk(gc, stubdomid, cis->disk, device);
+ if (rc != 0) goto out;
+
+ /* block dev eject */
+ /* Below is basically an open coding of:
+ * libxl_device_disk__remove(CTX, cis->domid, cis->disk, 0);
+ * ...since we can't call it from within libxl.
+ */
+ libxl__prepare_ao_device(ao, &cis->aodev_del);
+ cis->aodev_del.action = LIBXL__DEVICE_ACTION_REMOVE;
+ cis->aodev_del.dev = device;
+ cis->aodev_del.callback = cdrom_insert_stubdom_disk_ejected_aocomplete;
+ cis->aodev_del.force.flag = LIBXL__FORCE_OFF;
+ libxl__initiate_device_generic_remove(egc, &cis->aodev_del);
+ return;
+
+ out:
+ cdrom_insert_done(egc, cis, rc); /* must be last */
+}
+
+static void cdrom_insert_stubdom_disk_ejected_aocomplete(libxl__egc *egc,
+ libxl__ao_device
*aodev)
+{
+ STATE_AO_GC(aodev->ao);
+ libxl__cdrom_insert_state *cis = CONTAINER_OF(aodev, *cis, aodev_del);
+
+ LOGD(DEBUG, cis->domid, "rc=%d", aodev->rc);
+ if (aodev->rc) {
+ if (aodev->dev) {
+ LOGD(ERROR, aodev->dev->domid, "Unable to %s %s with id %u",
+ libxl__device_action_to_string(aodev->action),
+ libxl__device_kind_to_string(aodev->dev->kind),
+ aodev->dev->devid);
+ } else {
+ LOG(ERROR, "unable to %s device",
+ libxl__device_action_to_string(aodev->action));
+ }
+ goto out;
+ }
+
+ cdrom_insert_stubdom_disk_ejected(egc, &cis->qmp, NULL, aodev->rc);
+ return;
+
+ out:
+ cdrom_insert_done(egc, cis, aodev->rc);
+}
+
+static void cdrom_insert_stubdom_disk_ejected(libxl__egc *egc,
+ libxl__ev_qmp *qmp,
+ const libxl__json_object
*response,
+ int rc)
+{
+ libxl__cdrom_insert_state *cis = CONTAINER_OF(qmp, *cis, qmp);
+ STATE_AO_GC(cis->ao);
+ domid_t stubdomid = libxl_get_stubdom_id(CTX, cis->domid);
+
+ LOGD(DEBUG, cis->domid, "rc=%d", rc);
+ if (rc) goto out;
+
+ /* block dev insert */
+ libxl__prepare_ao_device(ao, &cis->aodev);
+ /* set an ao callback to end up in cdrom_insert_ejected */
+ cis->aodev.callback = cdrom_insert_ejected_aodevcb;
+ libxl__device_disk_add(egc, stubdomid, cis->disk, &cis->aodev);
+ return;
+
+ out:
+ cdrom_insert_done(egc, cis, rc); /* must be last */
+}
+
+static void cdrom_insert_ejected_aodevcb(libxl__egc *egc,
+ libxl__ao_device *aodev)
+{
+ STATE_AO_GC(aodev->ao);
+ libxl__cdrom_insert_state *cis = CONTAINER_OF(aodev, *cis, aodev);
+
+ LOGD(DEBUG, cis->domid, "rc=%d", aodev->rc);
+ if (aodev->rc) {
+ if (aodev->dev) {
+ LOGD(ERROR, aodev->dev->domid, "Unable to %s %s with id %u",
+ libxl__device_action_to_string(aodev->action),
+ libxl__device_kind_to_string(aodev->dev->kind),
+ aodev->dev->devid);
+ } else {
+ LOG(ERROR, "unable to %s device",
+ libxl__device_action_to_string(aodev->action));
+ }
+ goto out;
+ }
+
+ cdrom_insert_ejected(egc, &cis->qmp, NULL, aodev->rc);
+ return;
+
+ out:
+ cdrom_insert_done(egc, cis, aodev->rc);
+}
+
static void cdrom_insert_ejected(libxl__egc *egc,
libxl__ev_qmp *qmp,
const libxl__json_object *response,
@@ -983,9 +1167,10 @@ static void cdrom_insert_ejected(libxl__egc *egc,
libxl_domain_config_init(&d_config);
+ LOGD(DEBUG, cis->domid, "rc=%d", rc);
if (rc) goto out;
- rc = libxl__device_from_disk(gc, domid, disk, &device);
+ rc = libxl__device_from_disk(gc, cis->disk_domid, disk, &device);
if (rc) goto out;
be_path = libxl__device_backend_path(gc, &device);
libxl_path = libxl__device_libxl_path(gc, &device);
@@ -1032,7 +1217,7 @@ static void cdrom_insert_ejected(libxl__egc *egc,
*/
rc = libxl__get_domain_configuration(gc, domid, &d_config);
- if (rc) goto out;
+ if (rc && rc != ERROR_JSON_CONFIG_EMPTY) goto out;
device_add_domain_config(gc, &d_config, &libxl__disk_devtype,
&cis->disk_saved);
@@ -1040,10 +1225,15 @@ static void cdrom_insert_ejected(libxl__egc *egc,
rc = libxl__dm_check_start(gc, &d_config, domid);
if (rc) goto out;
+ LOGD(DEBUG, cis->domid, "stubdom_id=%d",
+ libxl_get_stubdom_id(CTX, cis->domid));
+ /* A linux stubdom will perform add-fd with calculated stubdom_fdset. */
if (cis->dm_ver == LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN &&
+ libxl_get_stubdom_id(CTX, cis->domid) == 0 &&
disk->format != LIBXL_DISK_FORMAT_EMPTY) {
libxl__json_object *args = NULL;
+ LOGD(DEBUG, cis->domid, "Doing qmp add-fd path");
assert(qmp->payload_fd == -1);
qmp->payload_fd = open(disk->pdev_path, O_RDONLY);
if (qmp->payload_fd < 0) {
@@ -1062,20 +1252,28 @@ static void cdrom_insert_ejected(libxl__egc *egc,
if (rc) goto out;
has_callback = true;
} else {
+ LOGD(DEBUG, cis->domid, "Skipping qmp add-fd path");
has_callback = false;
}
rc = 0;
out:
+ LOGD(DEBUG, cis->domid, "out label rc=%d", rc);
libxl__xs_transaction_abort(gc, &t);
libxl_domain_config_dispose(&d_config);
if (data_lock) libxl__unlock_file(data_lock);
if (rc) {
cdrom_insert_done(egc, cis, rc); /* must be last */
} else if (!has_callback) {
- /* Only called if no asynchronous callback are set. */
- cdrom_insert_inserted(egc, qmp, NULL, 0); /* must be last */
+ LOGD(DEBUG, cis->domid, "no callback; stubdom_id=%d",
+ libxl_get_stubdom_id(CTX, cis->domid));
+ if (libxl_get_stubdom_id(CTX, cis->domid) == 0) {
+ /* Only called if no asynchronous callback are set. */
+ cdrom_insert_inserted(egc, qmp, NULL, 0); /* must be last */
+ } else {
+ cdrom_insert_addfd_cb(egc, qmp, NULL, 0);
+ }
}
}
@@ -1094,17 +1292,24 @@ static void cdrom_insert_addfd_cb(libxl__egc *egc,
/* convenience aliases */
libxl_device_disk *disk = cis->disk;
- close(qmp->payload_fd);
- qmp->payload_fd = -1;
+ LOGD(DEBUG, cis->domid, "rc=%d", rc);
if (rc) goto out;
- o = libxl__json_map_get("fdset-id", response, JSON_INTEGER);
- if (!o) {
- rc = ERROR_FAIL;
- goto out;
+ /* response non-NULL only for non-stubdom */
+ if (response) {
+ close(qmp->payload_fd);
+ qmp->payload_fd = -1;
+
+ o = libxl__json_map_get("fdset-id", response, JSON_INTEGER);
+ if (!o) {
+ rc = ERROR_FAIL;
+ goto out;
+ }
+ fdset = libxl__json_object_get_integer(o);
+ } else {
+ fdset = cis->stubdom_fdset;
}
- fdset = libxl__json_object_get_integer(o);
devid = libxl__device_disk_dev_number(disk->vdev, NULL, NULL);
qmp->callback = cdrom_insert_inserted;
@@ -1117,8 +1322,13 @@ static void cdrom_insert_addfd_cb(libxl__egc *egc,
if (libxl__qmp_ev_qemu_compare_version(qmp, 2, 8, 0) >= 0) {
QMP_PARAMETERS_SPRINTF(&args, "id", "ide-%i", devid);
QMP_PARAMETERS_SPRINTF(&args, "filename", "/dev/fdset/%d", fdset);
- libxl__qmp_param_add_string(gc, &args, "format",
- libxl__qemu_disk_format_string(disk->format));
+ if (response) {
+ libxl__qmp_param_add_string(gc, &args, "format",
+ libxl__qemu_disk_format_string(disk->format));
+ } else {
+ /* Stubdom is using blockdev /dev/xvd* */
+ libxl__qmp_param_add_string(gc, &args, "format", "host_device");
+ }
rc = libxl__ev_qmp_send(egc, qmp, "blockdev-change-medium", args);
} else {
QMP_PARAMETERS_SPRINTF(&args, "device", "ide-%i", devid);
@@ -1132,13 +1342,22 @@ out:
cdrom_insert_done(egc, cis, rc); /* must be last */
}
+static void cdrom_insert_addfd_retry(libxl__egc *egc, libxl__ev_time *ev,
+ const struct timeval *requested_abs,
+ int rc)
+{
+ libxl__cdrom_insert_state *cis = CONTAINER_OF(ev, *cis, timeout_retry);
+
+ cdrom_insert_addfd_cb(egc, &cis->qmp, NULL, 0);
+}
+
static void cdrom_insert_inserted(libxl__egc *egc,
libxl__ev_qmp *qmp,
const libxl__json_object *response,
int rc)
{
- EGC_GC;
libxl__cdrom_insert_state *cis = CONTAINER_OF(qmp, *cis, qmp);
+ STATE_AO_GC(cis->ao);
libxl__flock *data_lock = NULL;
libxl_domain_config d_config;
flexarray_t *insert = NULL;
@@ -1153,9 +1372,22 @@ static void cdrom_insert_inserted(libxl__egc *egc,
libxl_domain_config_init(&d_config);
- if (rc) goto out;
+ LOGD(DEBUG, cis->domid, "rc=%d", rc);
+
+ if (rc) {
+ if (cis->retries++ < 10 ) {
+ LOGD(DEBUG, qmp->domid, "Retrying QMP cdrom change\n");
+ rc = libxl__ev_time_register_rel(ao, &cis->timeout_retry,
+ cdrom_insert_addfd_retry, 100);
+ if (rc) goto out;
+
+ return;
+ } else {
+ goto out;
+ }
+ }
- rc = libxl__device_from_disk(gc, domid, disk, &device);
+ rc = libxl__device_from_disk(gc, cis->disk_domid, disk, &device);
if (rc) goto out;
be_path = libxl__device_backend_path(gc, &device);
libxl_path = libxl__device_libxl_path(gc, &device);
@@ -1167,7 +1399,7 @@ static void cdrom_insert_inserted(libxl__egc *egc,
}
rc = libxl__get_domain_configuration(gc, domid, &d_config);
- if (rc) goto out;
+ if (rc && rc != ERROR_JSON_CONFIG_EMPTY) goto out;
device_add_domain_config(gc, &d_config, &libxl__disk_devtype,
&cis->disk_saved);
@@ -1176,10 +1408,14 @@ static void cdrom_insert_inserted(libxl__egc *egc,
flexarray_append_pair(insert, "type",
libxl__device_disk_string_of_backend(disk->backend));
if (disk->format != LIBXL_DISK_FORMAT_EMPTY)
- flexarray_append_pair(insert, "params",
- GCSPRINTF("%s:%s",
- libxl__device_disk_string_of_format(disk->format),
- disk->pdev_path));
+ if (disk->backend == LIBXL_DISK_BACKEND_QDISK) {
+ flexarray_append_pair(insert, "params",
+ GCSPRINTF("%s:%s",
+ libxl__device_disk_string_of_format(disk->format),
+ disk->pdev_path));
+ } else {
+ flexarray_append_pair(insert, "params", disk->pdev_path);
+ }
else
flexarray_append_pair(insert, "params", "");
@@ -1237,7 +1473,10 @@ static void cdrom_insert_done(libxl__egc *egc,
{
EGC_GC;
+ LOGD(DEBUG, cis->domid, "rc=%d", rc);
+
libxl__ev_time_deregister(gc, &cis->time);
+ libxl__ev_time_deregister(gc, &cis->timeout_retry);
libxl__ev_qmp_dispose(gc, &cis->qmp);
if (cis->qmp.payload_fd >= 0) close(cis->qmp.payload_fd);
libxl__ev_slowlock_unlock(gc, &cis->qmp_lock);
--
2.43.0
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