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2013-10-11block: Add bdrv_get_specific_infoMax Reitz2-0/+2
Add a function for retrieving an ImageInfoSpecific object from a block driver. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11qapi: make use of new BlockJobTypeFam Zheng1-1/+1
Switch the string to enum type BlockJobType in BlockJobDriver. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11blockjob: rename BlockJobType to BlockJobDriverFam Zheng1-6/+6
We will use BlockJobType as the enum type name of block jobs in QAPI, rename current BlockJobType to BlockJobDriver, which will eventually become a set of operations, similar to block drivers. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25block: introduce BlockDriver.bdrv_needs_filename to enable some drivers.Benoît Canet1-0/+6
Some drivers will have driver specifics options but no filename. This new bool allow the block layer to treat them correctly. The .bdrv_needs_filename is set in drivers not having .bdrv_parse_filename and not having .bdrv_open. The first exception to this rule will be the quorum driver. Signed-off-by: Benoit Canet <benoit@irqsave.net> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12block: Error parameter for create functionsMax Reitz1-2/+3
Add an Error ** parameter to bdrv_create and its associated functions to allow more specific error messages. Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12block: Error parameter for open functionsMax Reitz1-3/+3
Add an Error ** parameter to bdrv_open, bdrv_file_open and associated functions to allow more specific error messages. Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12bdrv: Use "Error" for creating imagesMax Reitz1-1/+2
Add an Error ** parameter to BlockDriver.bdrv_create to allow more specific error messages. Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12bdrv: Use "Error" for opening imagesMax Reitz1-2/+4
Add an Error ** parameter to BlockDriver.bdrv_open and BlockDriver.bdrv_file_open to allow more specific error messages. Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12snapshot: distinguish id and name in snapshot deleteWenchao Xia2-2/+11
Snapshot creation actually already distinguish id and name since it take a structured parameter *sn, but delete can't. Later an accurate delete is needed in qmp_transaction abort and blockdev-snapshot-delete-sync, so change its prototype. Also *errp is added to tip error, but return value is kepted to let caller check what kind of error happens. Existing caller for it are savevm, delvm and qemu-img, they are not impacted by introducing a new function bdrv_snapshot_delete_by_id_or_name(), which check the return value and do the operation again. Before this patch: For qcow2, it search id first then name to find the one to delete. For rbd, it search name. For sheepdog, it does nothing. After this patch: For qcow2, logic is the same by call it twice in caller. For rbd, it always fails in delete with id, but still search for name in second try, no change to user. Some code for *errp is based on Pavel's patch. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12snapshot: new function bdrv_snapshot_find_by_id_and_name()Wenchao Xia1-0/+6
To make it clear about id and name in searching, add this API to distinguish them. Caller can choose to search by id or name, *errp will be set only for exception. Some code are modified based on Pavel's patch. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Pavel Hrdina <phrdina@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12block: Image file option amendmentMax Reitz2-0/+5
This patch adds the "amend" option to qemu-img which allows changing image options on existing image files. It also adds the generic bdrv implementation which is basically just a wrapper for the image format specific function. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-06block: define get_block_status return valuePaolo Bonzini1-0/+26
Define the return value of get_block_status. Bits 0, 1, 2 and 9-62 are valid; bit 63 (the sign bit) is reserved for errors. Bits 3-8 are left for future extensions. The return code is compatible with the old is_allocated API: if a driver only returns 0 or 1 (aka BDRV_BLOCK_DATA) like is_allocated used to, clients of is_allocated will not have any change in behavior. Still, we will return more precise information in the next patches and the new definition of bdrv_is_allocated is already prepared for this. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: introduce bdrv_get_block_status APIPaolo Bonzini2-1/+3
For now, bdrv_get_block_status is just another name for bdrv_is_allocated. The next patches will add more flags. This also touches all block drivers with a mostly mechanical rename. The sole exception is cow; because it calls cow_co_is_allocated from the read code, we keep that function and make cow_co_get_block_status a wrapper. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: remove bdrv_is_allocated_above/bdrv_co_is_allocated_above distinctionPaolo Bonzini1-4/+0
Now that bdrv_is_allocated detects coroutine context, the two can use the same code. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: make bdrv_co_is_allocated staticPaolo Bonzini1-2/+0
bdrv_is_allocated can detect coroutine context and go through a fast path, similar to other block layer functions. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: make bdrv_delete() staticFam Zheng1-1/+0
Manage BlockDriverState lifecycle with refcnt, so bdrv_delete() is no longer public and should be called by bdrv_unref() if refcnt is decreased to 0. This is an identical change because effectively, there's no multiple reference of BDS now: no caller of bdrv_ref() yet, only bdrv_new() sets bs->refcnt to 1, so all bdrv_unref() now actually delete the BDS. Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: implement reference count for BlockDriverStateFam Zheng2-0/+3
Introduce bdrv_ref/bdrv_unref to manage the lifecycle of BlockDriverState. They are unused for now but will used to replace bdrv_delete() later. Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: Enable the new throttling code in the block layer.Benoît Canet2-27/+6
Signed-off-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-02qcow2-refcount: Repair shared refcount blocksMax Reitz1-0/+1
If the refcount of a refcount block is greater than one, we can at least try to repair that problem by duplicating the affected block. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-08-22aio / timers: convert block_job_sleep_ns and co_sleep_ns to new APIAlex Bligh2-2/+2
Convert block_job_sleep_ns and co_sleep_ns to use the new timer API. Signed-off-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22aio / timers: Add aio_timer_init & aio_timer_new wrappersAlex Bligh1-0/+43
Add aio_timer_init and aio_timer_new wrapper functions. Signed-off-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22aio / timers: Add QEMUTimerListGroup to AioContextAlex Bligh1-0/+4
Add a QEMUTimerListGroup each AioContext (meaning a QEMUTimerList associated with each clock is added) and delete it when the AioContext is freed. Signed-off-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22aio / timers: Untangle include filesAlex Bligh3-2/+5
include/qemu/timer.h has no need to include main-loop.h and doing so causes an issue for the next patch. Unfortunately various files assume including timers.h will pull in main-loop.h. Untangle this mess. Signed-off-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22block: Introduce bs->zero_beyond_eofAsias He1-0/+3
In 4146b46c42e0989cb5842e04d88ab6ccb1713a48 (block: Produce zeros when protocols reading beyond end of file), we break qemu-iotests ./check -qcow2 022. This happens because qcow2 temporarily sets ->growable = 1 for vmstate accesses (which are stored beyond the end of regular image data). We introduce the bs->zero_beyond_eof to allow qcow2_load_vmstate() to disable ->zero_beyond_eof temporarily in addition to enable ->growable. [Since the broken patch "block: Produce zeros when protocols reading beyond end of file" has not been merged yet, I have applied this fix *first* and will then apply the next patch to keep the tree bisectable. -- Stefan] Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-19aio: drop io_flush argumentStefan Hajnoczi1-12/+2
The .io_flush() handler no longer exists and has no users. Drop the io_flush argument to aio_set_fd_handler() and related functions. The AioFlushEventNotifierHandler and AioFlushHandler typedefs are no longer used and are dropped too. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-29block: Repair the throttling code.Benoît Canet1-2/+7
The throttling code was segfaulting since commit 02ffb504485f0920cfc75a0982a602f824a9a4f4 because some qemu_co_queue_next caller does not run in a coroutine. qemu_co_queue_do_restart assume that the caller is a coroutinne. As suggested by Stefan fix this by entering the coroutine directly. Also make sure like suggested that qemu_co_queue_next() and qemu_co_queue_restart_all() can be called only in coroutines. Signed-off-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-26Implement sync modes for drive-backup.Ian Main1-1/+3
This patch adds sync-modes to the drive-backup interface and implements the FULL, NONE and TOP modes of synchronization. FULL performs as before copying the entire contents of the drive while preserving the point-in-time using CoW. NONE only copies new writes to the target drive. TOP copies changes to the topmost drive image and preserves the point-in-time using CoW. For sync mode TOP are creating a new target image using the same backing file as the original disk image. Then any new data that has been laid on top of it since creation is copied in the main backup_run() loop. There is an extra check in the 'TOP' case so that we don't bother to copy all the data of the backing file as it already exists in the target. This is where the bdrv_co_is_allocated() is used to determine if the data exists in the topmost layer or below. Also any new data being written is intercepted via the write_notifier hook which ends up calling backup_do_cow() to copy old data out before it gets overwritten. For mode 'NONE' we create the new target image and only copy in the original data from the disk image starting from the time the call was made. This preserves the point in time data by only copying the parts that are *going to change* to the target image. This way we can reconstruct the final image by checking to see if the given block exists in the new target image first, and if it does not, you can get it from the original image. This is basically an optimization allowing you to do point-in-time snapshots with low overhead vs the 'FULL' version. Since there is no old data to copy out the loop in backup_run() for the NONE case just calls qemu_coroutine_yield() which only wakes up after an event (usually cancel in this case). The rest is handled by the before_write notifier which again calls backup_do_cow() to write out the old data so it can be preserved. Signed-off-by: Ian Main <imain@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-07-19block: add bdrv_write_zeroes()Peter Lieven1-0/+2
Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-19QEMUBH: make AioContext's bh re-entrantLiu Ping Fan1-0/+7
BH will be used outside big lock, so introduce lock to protect between the writers, ie, bh's adders and deleter. The lock only affects the writers and bh's callback does not take this extra lock. Note that for the same AioContext, aio_bh_poll() can not run in parallel yet. Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-15block: Add return value for bdrv_flush_all()Kevin Wolf1-1/+1
bdrv_flush() can fail, and bdrv_flush_all() should return an error as well if this happens for a block device. It returns the first error return now, but still at least tries to flush the remaining devices even in error cases. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-15block: Don't parse protocol from file.filenameKevin Wolf1-1/+2
One of the major reasons for doing something new for -blockdev and blockdev-add was that the old block layer code parses filenames instead of just taking them literally. So we should really leave it untouched when it's passing using the new interfaces (like -drive file.filename=...). This allows opening relative file names that contain a colon. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-06-28block: change default of .has_zero_init to 0Peter Lieven1-0/+1
.has_zero_init defaults to 1 for all formats and protocols. this is a dangerous default since this means that all new added drivers need to manually overwrite it to 0 if they do not ensure that a device is zero initialized after bdrv_create(). if a driver needs to explicitly set this value to 1 its easier to verify the correctness in the review process. during review of the existing drivers it turned out that ssh and gluster had a wrong default of 1. both protocols support host_devices as backend which are not by default zero initialized. this wrong assumption will lead to possible corruption if qemu-img convert is used to write to such a backend. vpc and vmdk also defaulted to 1 altough they support fixed respectively flat extends. this has to be addresses in separate patches. both formats as well as the mentioned ssh and gluster are turned to the default of 0 with this patch for safety. a similar problem with the wrong default existed for iscsi most likely because the driver developer did oversee the default value of 1. Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-28block: add basic backup support to block driverDietmar Maurer1-0/+19
backup_start() creates a block job that copies a point-in-time snapshot of a block device to a target block device. We call backup_do_cow() for each write during backup. That function reads the original data from the block device before it gets overwritten. The data is then written to the target device. Currently backup cluster size is hardcoded to 65536 bytes. [I made a number of changes to Dietmar's original patch and folded them in to make code review easy. Here is the full list: * Drop BackupDumpFunc interface in favor of a target block device * Detect zero clusters with buffer_is_zero() and use bdrv_co_write_zeroes() * Use 0 delay instead of 1us, like other block jobs * Unify creation/start functions into backup_start() * Simplify cleanup, free bitmap in backup_run() instead of cb * function * Use HBitmap to avoid duplicating bitmap code * Use bdrv_getlength() instead of accessing ->total_sectors * directly * Delete the backup.h header file, it is no longer necessary * Move ./backup.c to block/backup.c * Remove #ifdefed out code * Coding style and whitespace cleanups * Use bdrv_add_before_write_notifier() instead of blockjob-specific hooks * Keep our own in-flight CowRequest list instead of using block.c tracked requests. This means a little code duplication but is much simpler than trying to share the tracked requests list and use the backup block size. * Add on_source_error and on_target_error error handling. * Use trace events instead of DPRINTF() -- stefanha] Signed-off-by: Dietmar Maurer <dietmar@proxmox.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-28block: add bdrv_add_before_write_notifier()Stefan Hajnoczi1-1/+22
The bdrv_add_before_write_notifier() function installs a callback that is invoked before a write request is processed. This will be used to implement copy-on-write point-in-time snapshots where we need to copy out old data before overwriting it. Note that BdrvTrackedRequest is moved to block_int.h since it is passed to .notify() functions. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-27rdma: export yield_until_fd_readable()Michael R. Hines1-0/+6
The RDMA event channel can be made non-blocking just like a TCP socket. Exporting this function allows us to yield so that the QEMU monitor remains available. Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Chegu Vinod <chegu_vinod@hp.com> Tested-by: Chegu Vinod <chegu_vinod@hp.com> Tested-by: Michael R. Hines <mrhines@us.ibm.com> Signed-off-by: Michael R. Hines <mrhines@us.ibm.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-06-07qmp: add ImageInfo in BlockDeviceInfo used by query-blockWenchao Xia1-1/+3
Now image info will be retrieved as an embbed json object inside BlockDeviceInfo, backing chain info and all related internal snapshot info can be got in the enhanced recursive structure of ImageInfo. New recursive member *backing-image is added to reflect the backing chain status. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-07block: add image info query function bdrv_query_image_info()Wenchao Xia1-3/+3
This patch adds function bdrv_query_image_info(), which will retrieve image info in qmp object format. The implementation is based on the code moved from qemu-img.c, but uses block layer function to get snapshot info. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-07block: add snapshot info query function bdrv_query_snapshot_info_list()Wenchao Xia1-1/+3
This patch adds function bdrv_query_snapshot_info_list(), which will retrieve snapshot info of an image in qmp object format. The implementation is based on the code moved from qemu-img.c with modification to fit more for qmp based block layer API. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-06blkdebug: Add BLKDBG_FLUSH_TO_OS/DISK eventsKevin Wolf1-0/+3
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-04block: dump snapshot and image info to specified outputWenchao Xia1-2/+4
bdrv_snapshot_dump() and bdrv_image_info_dump() do not dump to a buffer now, some internal buffers are still used for format control, which have no chance to be truncated. As a result, these two functions have no more issue of truncation, and they can be used by both qemu and qemu-img with correct parameter specified. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-04block: move qmp and info dump related code to block/qapi.cWenchao Xia3-9/+42
This patch is a pure code move patch, except following modification: 1 get_human_readable_size() is changed to static function. 2 dump_human_image_info() is renamed to bdrv_image_info_dump(). 3 in qmp_query_block() and qmp_query_blockstats, use bdrv_next(bs) instead of direct traverse of global array 'bdrv_states'. 4 collect_snapshots() and collect_image_info() are renamed, unused parameter *fmt in collect_image_info() is removed. 5 code style fix. To avoid conflict and tip better, macro in header file is BLOCK_QAPI_H instead of QAPI_H. Now block.h and snapshot.h are at the same level in include path, block_int.h and qapi.h will both include them. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-04block: move snapshot code in block.c to block/snapshot.cWenchao Xia2-21/+58
All snapshot related code, except bdrv_snapshot_dump() and bdrv_is_snapshot(), is moved to block/snapshot.c. bdrv_snapshot_dump() will be moved to another file later. bdrv_is_snapshot() is not related with internal snapshot. It also fixes small code style errors reported by check script. Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-04block: drop bs_snapshots global variableStefan Hajnoczi1-1/+0
The bs_snapshots global variable points to the BlockDriverState which will be used to save vmstate. This is really a savevm.c concept but was moved into block.c:bdrv_snapshots() when it became clear that hotplug could result in a dangling pointer. While auditing the block layer's global state I came upon bs_snapshots and realized that a variable is not necessary here. Simply find the first BlockDriverState capable of internal snapshots each time this is needed. The behavior of bdrv_snapshots() is preserved across hotplug because new drives are always appended to the bdrv_states list. This means that calling the new find_vmstate_bs() function is idempotent - it returns the same BlockDriverState unless it was hot-unplugged. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-04block: add block driver read only whitelistFam Zheng1-1/+2
We may want to include a driver in the whitelist for read only tasks such as diagnosing or exporting guest data (with libguestfs as a good example). This patch introduces a readonly whitelist option, and for backward compatibility, the old configure option --block-drv-whitelist is now an alias to rw whitelist. Drivers in readonly list is only permitted to open file readonly, and returns -ENOTSUP for RW opening. E.g. To include vmdk readonly, and others read+write: ./configure --target-list=x86_64-softmmu \ --block-drv-rw-whitelist=qcow2,raw,file,qed \ --block-drv-ro-whitelist=vmdk Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-05-24coroutine: stop using AioContext in CoQueueStefan Hajnoczi1-0/+4
qemu_co_queue_next(&queue) arranges that the next queued coroutine is run at a later point in time. This deferred restart is useful because the caller may not want to transfer control yet. This behavior was implemented using QEMUBH in the past, which meant that CoQueue (and hence CoMutex and CoRwlock) had a dependency on the AioContext event loop. This hidden dependency causes trouble when we move to a world with multiple event loops - now qemu_co_queue_next() needs to know which event loop to schedule the QEMUBH in. After pondering how to stash AioContext I realized the best solution is to not use AioContext at all. This patch implements the deferred restart behavior purely in terms of coroutines and no longer uses QEMUBH. Here is how it works: Each Coroutine has a wakeup queue that starts out empty. When qemu_co_queue_next() is called, the next coroutine is added to our wakeup queue. The wakeup queue is processed when we yield or terminate. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-05-03nbd: support large NBD requestsStefan Hajnoczi1-1/+2
The Linux nbd driver recently increased the maximum supported request size up to 32 MB: commit 078be02b80359a541928c899c2631f39628f56df Author: Michal Belczyk <belczyk@bsd.krakow.pl> Date: Tue Apr 30 15:28:28 2013 -0700 nbd: increase default and max request sizes Raise the default max request size for nbd to 128KB (from 127KB) to get it 4KB aligned. This patch also allows the max request size to be increased (via /sys/block/nbd<x>/queue/max_sectors_kb) to 32MB. QEMU's 1 MB buffers are too small to handle these requests. This patch allocates data buffers dynamically and allows up to 32 MB per request. Reported-by: Nick Thomas <nick@bytemark.co.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-22block: Remove filename parameter from .bdrv_file_open()Kevin Wolf1-2/+1
It is unused now in all block drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22block: Add driver-specific options for backing filesKevin Wolf1-1/+1
Options starting in "backing." are passed to the backing file now. If you don't need to specify the filename for the backing file, you can add it on the command line instead of in the image file: $ qemu-nbd -t /tmp/test.img $ qemu-img create -f qcow2 empty.qcow2 1G $ qemu-system-x86_64 -drive file=empty.qcow2,backing.file.driver=nbd,\ backing.file.host=localhost Note that this doesn't override the backing filename from the image. If the image has one, this will fail because NBD doesn't want the options and a filename at the same time. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-15block: Introduce bdrv_pwritev() for qcow2_save_vmstateKevin Wolf1-0/+2
Directly pass the QEMUIOVector on instead of linearising it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-15block: Introduce bdrv_writev_vmstateKevin Wolf2-2/+3
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>