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authorRyan Harper <ryanh@us.ibm.com>2010-11-12 11:07:13 -0600
committerKevin Wolf <kwolf@redhat.com>2010-11-24 17:30:19 +0100
commit9063f81415f3518ef8206e74085c2a92c96890a0 (patch)
treeac5eb775dea385bff21fce6f063eb0348e413217 /blockdev.c
parent6fa2c95f279dda62aa7e3292cc424ff3fab6a602 (diff)
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Implement drive_del to decouple block removal from device removal
Currently device hotplug removal code is tied to device removal via ACPI. All pci devices that are removable via device_del() require the guest to respond to the request. In some cases the guest may not respond leaving the device still accessible to the guest. The management layer doesn't currently have a reliable way to revoke access to host resource in the presence of an uncooperative guest. This patch implements a new monitor command, drive_del, which provides an explicit command to revoke access to a host block device. drive_del first quiesces the block device (qemu_aio_flush; bdrv_flush() and bdrv_close()). This prevents further IO from being submitted against the host device. Finally, drive_del cleans up pointers between the drive object (host resource) and the device object (guest resource). Signed-off-by: Ryan Harper <ryanh@us.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'blockdev.c')
-rw-r--r--blockdev.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/blockdev.c b/blockdev.c
index 6cb179a..f6ac439 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -14,6 +14,8 @@
#include "qemu-option.h"
#include "qemu-config.h"
#include "sysemu.h"
+#include "hw/qdev.h"
+#include "block_int.h"
static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
@@ -597,3 +599,40 @@ int do_change_block(Monitor *mon, const char *device,
}
return monitor_read_bdrv_key_start(mon, bs, NULL, NULL);
}
+
+int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
+{
+ const char *id = qdict_get_str(qdict, "id");
+ BlockDriverState *bs;
+ BlockDriverState **ptr;
+ Property *prop;
+
+ bs = bdrv_find(id);
+ if (!bs) {
+ qerror_report(QERR_DEVICE_NOT_FOUND, id);
+ return -1;
+ }
+
+ /* quiesce block driver; prevent further io */
+ qemu_aio_flush();
+ bdrv_flush(bs);
+ bdrv_close(bs);
+
+ /* clean up guest state from pointing to host resource by
+ * finding and removing DeviceState "drive" property */
+ for (prop = bs->peer->info->props; prop && prop->name; prop++) {
+ if (prop->info->type == PROP_TYPE_DRIVE) {
+ ptr = qdev_get_prop_ptr(bs->peer, prop);
+ if ((*ptr) == bs) {
+ bdrv_detach(bs, bs->peer);
+ *ptr = NULL;
+ break;
+ }
+ }
+ }
+
+ /* clean up host side */
+ drive_uninit(drive_get_by_blockdev(bs));
+
+ return 0;
+}