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2017-01-16aio: document lockingPaolo Bonzini
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170112180800.21085-10-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-16aio: make ctx->list_lock a QemuLockCnt, subsuming ctx->walking_bhPaolo Bonzini
This will make it possible to walk the list of bottom halves without holding the AioContext lock---and in turn to call bottom half handlers without holding the lock. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170112180800.21085-4-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-16aio: rename bh_lock to list_lockPaolo Bonzini
This will be used for AioHandlers too. There is going to be little or no contention, so it is better to reuse the same lock. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170112180800.21085-2-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-16block: get rid of bdrv_io_unplugged_begin/endPaolo Bonzini
bdrv_io_plug and bdrv_io_unplug are only called (via their BlockBackend equivalents) after starting asynchronous I/O. bdrv_drain is not going to be called while they are running, because---even if a coroutine runs for some reason---it will only drain in the next iteration of the event loop through bdrv_co_yield_to_drain. So this mechanism is unnecessary, get rid of it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161129113334.605-1-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-09block: Rename raw-{posix,win32} to file-*.cEric Blake
These files deal with the file protocol, not the raw format (the file protocol is often used with other formats, and the raw format is not forced to use the file protocol). Rename things to make it a bit easier to follow. Suggested-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-01-03aio: self-tune polling timeStefan Hajnoczi
This patch is based on the algorithm for the kvm.ko halt_poll_ns parameter in Linux. The initial polling time is zero. If the event loop is woken up within the maximum polling time it means polling could be effective, so grow polling time. If the event loop is woken up beyond the maximum polling time it means polling is not effective, so shrink polling time. If the event loop makes progress within the current polling time then the sweet spot has been reached. This algorithm adjusts the polling time so it can adapt to variations in workloads. The goal is to reach the sweet spot while also recognizing when polling would hurt more than help. Two new trace events, poll_grow and poll_shrink, are added for observing polling time adjustment. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161201192652.9509-13-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-03aio: add .io_poll_begin/end() callbacksStefan Hajnoczi
The begin and end callbacks can be used to prepare for the polling loop and clean up when polling stops. Note that they may only be called once for multiple aio_poll() calls if polling continues to succeed. Once polling fails the end callback is invoked before aio_poll() resumes file descriptor monitoring. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161201192652.9509-11-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-03aio: add polling mode to AioContextStefan Hajnoczi
The AioContext event loop uses ppoll(2) or epoll_wait(2) to monitor file descriptors or until a timer expires. In cases like virtqueues, Linux AIO, and ThreadPool it is technically possible to wait for events via polling (i.e. continuously checking for events without blocking). Polling can be faster than blocking syscalls because file descriptors, the process scheduler, and system calls are bypassed. The main disadvantage to polling is that it increases CPU utilization. In classic polling configuration a full host CPU thread might run at 100% to respond to events as quickly as possible. This patch implements a timeout so we fall back to blocking syscalls if polling detects no activity. After the timeout no CPU cycles are wasted on polling until the next event loop iteration. The run_poll_handlers_begin() and run_poll_handlers_end() trace events are added to aid performance analysis and troubleshooting. If you need to know whether polling mode is being used, trace these events to find out. Note that the AioContext is now re-acquired before disabling notify_me in the non-polling case. This makes the code cleaner since notify_me was enabled outside the non-polling AioContext release region. This change is correct since it's safe to keep notify_me enabled longer (disabling is an optimization) but potentially causes unnecessary event_notifer_set() calls. I think the chance of performance regression is small here. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161201192652.9509-4-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-03aio: add AioPollFn and io_poll() interfaceStefan Hajnoczi
The new AioPollFn io_poll() argument to aio_set_fd_handler() and aio_set_event_handler() is used in the next patch. Keep this code change separate due to the number of files it touches. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161201192652.9509-3-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-03aio: add flag to skip fds to aio_dispatch()Stefan Hajnoczi
Polling mode will not call ppoll(2)/epoll_wait(2). Therefore we know there are no fds ready and should avoid looping over fd handlers in aio_dispatch(). Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161201192652.9509-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-12-22block: drop remaining legacy aio functions in commentYaowei Bai
Commit 87f68d318222563822b5c6b28192215fc4b4e441 (block: drop aio functions that operate on the main AioContext) drops qemu_aio_wait function references mostly while leaves these behind, clean up them. Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Message-Id: <1480566640-27264-3-git-send-email-baiyaowei@cmss.chinamobile.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-14blockjob: refactor backup_start as backup_job_createJohn Snow
Refactor backup_start as backup_job_create, which only creates the job, but does not automatically start it. The old interface, 'backup_start', is not kept in favor of limiting the number of nearly-identical interfaces that would have to be edited to keep up with QAPI changes in the future. Callers that wish to synchronously start the backup_block_job can instead just call block_job_start immediately after calling backup_job_create. Transactions are updated to use the new interface, calling block_job_start only during the .commit phase, which helps prevent race conditions where jobs may finish before we even finish building the transaction. This may happen, for instance, during empty block backup jobs. Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1478587839-9834-6-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-14blockjob: add block_job_startJohn Snow
Instead of automatically starting jobs at creation time via backup_start et al, we'd like to return a job object pointer that can be started manually at later point in time. For now, add the block_job_start mechanism and start the jobs automatically as we have been doing, with conversions job-by-job coming in later patches. Of note: cancellation of unstarted jobs will perform all the normal cleanup as if the job had started, particularly abort and clean. The only difference is that we will not emit any events, because the job never actually started. Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1478587839-9834-5-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-14blockjob: add .start fieldJohn Snow
Add an explicit start field to specify the entrypoint. We already have ownership of the coroutine itself AND managing the lifetime of the coroutine, let's take control of creation of the coroutine, too. This will allow us to delay creation of the actual coroutine until we know we'll actually start a BlockJob in block_job_start. This avoids the sticky question of how to "un-create" a Coroutine that hasn't been started yet. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1478587839-9834-4-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-14blockjob: add .clean propertyJohn Snow
Cleaning up after we have deferred to the main thread but before the transaction has converged can be dangerous and result in deadlocks if the job cleanup invokes any BH polling loops. A job may attempt to begin cleaning up, but may induce another job to enter its cleanup routine. The second job, part of our same transaction, will block waiting for the first job to finish, so neither job may now make progress. To rectify this, allow jobs to register a cleanup operation that will always run regardless of if the job was in a transaction or not, and if the transaction job group completed successfully or not. Move sensitive cleanup to this callback instead which is guaranteed to be run only after the transaction has converged, which removes sensitive timing constraints from said cleanup. Furthermore, in future patches these cleanup operations will be performed regardless of whether or not we actually started the job. Therefore, cleanup callbacks should essentially confine themselves to undoing create operations, e.g. setup actions taken in what is now backup_start. Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1478587839-9834-3-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-03Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into stagingStefan Hajnoczi
* NBD bugfix (Changlong) * NBD write zeroes support (Eric) * Memory backend fixes (Haozhong) * Atomics fix (Alex) * New AVX512 features (Luwei) * "make check" logging fix (Paolo) * Chardev refactoring fallout (Paolo) * Small checkpatch improvements (Paolo, Jeff) # gpg: Signature made Wed 02 Nov 2016 08:31:11 AM GMT # gpg: using RSA key 0xBFFBD25F78C7AE83 # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * remotes/bonzini/tags/for-upstream: (30 commits) main-loop: Suppress I/O thread warning under qtest docs/rcu.txt: Fix minor typo vl: exit qemu on guest panic if -no-shutdown is not set checkpatch: allow spaces before parenthesis for 'coroutine_fn' x86: add AVX512_4VNNIW and AVX512_4FMAPS features slirp: fix CharDriver breakage qemu-char: do not forward events through the mux until QEMU has started nbd: Implement NBD_CMD_WRITE_ZEROES on client nbd: Implement NBD_CMD_WRITE_ZEROES on server nbd: Improve server handling of shutdown requests nbd: Refactor conversion to errno to silence checkpatch nbd: Support shorter handshake nbd: Less allocation during NBD_OPT_LIST nbd: Let client skip portions of server reply nbd: Let server know when client gives up negotiation nbd: Share common option-sending code in client nbd: Send message along with server NBD_REP_ERR errors nbd: Share common reply-sending code in server nbd: Rename struct nbd_request and nbd_reply nbd: Rename NbdClientSession to NBDClientSession ... Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-11-02nbd: Implement NBD_CMD_WRITE_ZEROES on serverEric Blake
Upstream NBD protocol recently added the ability to efficiently write zeroes without having to send the zeroes over the wire, along with a flag to control whether the client wants to allow a hole. Note that when it comes to requiring full allocation, vs. permitting optimizations, the NBD spec intentionally picked a different sense for the flag; the rules in qemu are: MAY_UNMAP == 0: must write zeroes MAY_UNMAP == 1: may use holes if reads will see zeroes while in NBD, the rules are: FLAG_NO_HOLE == 1: must write zeroes FLAG_NO_HOLE == 0: may use holes if reads will see zeroes In all cases, the 'may use holes' scenario is optional (the server need not use a hole, and must not use a hole if subsequent reads would not see zeroes). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1476469998-28592-16-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02nbd: Improve server handling of shutdown requestsEric Blake
NBD commit 6d34500b clarified how clients and servers are supposed to behave before closing a connection. It added NBD_REP_ERR_SHUTDOWN (for the server to announce it is about to go away during option haggling, so the client should quit sending NBD_OPT_* other than NBD_OPT_ABORT) and ESHUTDOWN (for the server to announce it is about to go away during transmission, so the client should quit sending NBD_CMD_* other than NBD_CMD_DISC). It also clarified that NBD_OPT_ABORT gets a reply, while NBD_CMD_DISC does not. This patch merely adds the missing reply to NBD_OPT_ABORT and teaches the client to recognize server errors. Actually teaching the server to send NBD_REP_ERR_SHUTDOWN or ESHUTDOWN would require knowing that the server has been requested to shut down soon (maybe we could do that by installing a SIGINT handler in qemu-nbd, which transitions from RUNNING to a new state that waits for the client to react, rather than just out-right quitting - but that's a bigger task for another day). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1476469998-28592-15-git-send-email-eblake@redhat.com> [Move dummy ESHUTDOWN to include/qemu/osdep.h. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02nbd: Support shorter handshakeEric Blake
The NBD Protocol allows the server and client to mutually agree on a shorter handshake (omit the 124 bytes of reserved 0), via the server advertising NBD_FLAG_NO_ZEROES and the client acknowledging with NBD_FLAG_C_NO_ZEROES (only possible in newstyle, whether or not it is fixed newstyle). It doesn't shave much off the wire, but we might as well implement it. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alex Bligh <alex@alex.org.uk> Message-Id: <1476469998-28592-13-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02nbd: Share common option-sending code in clientEric Blake
Rather than open-coding each option request, it's easier to have common helper functions do the work. That in turn requires having convenient packed types for handling option requests and replies. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1476469998-28592-9-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02nbd: Rename struct nbd_request and nbd_replyEric Blake
Our coding convention prefers CamelCase names, and we already have other existing structs with NBDFoo naming. Let's be consistent, before later patches add even more structs. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1476469998-28592-6-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02nbd: Treat flags vs. command type as separate fieldsEric Blake
Current upstream NBD documents that requests have a 16-bit flags, followed by a 16-bit type integer; although older versions mentioned only a 32-bit field with masking to find flags. Since the protocol is in network order (big-endian over the wire), the ABI is unchanged; but dealing with the flags as a separate field rather than masking will make it easier to add support for upcoming NBD extensions that increase the number of both flags and commands. Improve some comments in nbd.h based on the current upstream NBD protocol (https://github.com/yoe/nbd/blob/master/doc/proto.md), and touch some nearby code to keep checkpatch.pl happy. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1476469998-28592-3-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-02nbd: Add qemu-nbd -D for human-readable descriptionEric Blake
The NBD protocol allows servers to advertise a human-readable description alongside an export name during NBD_OPT_LIST. Add an option to pass through the user's string to the NBD client. Doing this also makes it easier to test commit 200650d4, which is the client counterpart of receiving the description. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1476469998-28592-2-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-01blockjobs: fix documentationJohn Snow
(Trivial) Fix wrong function names in documentation. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-8-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01blockjobs: split interface into public/private, Part 1John Snow
To make it a little more obvious which functions are intended to be public interface and which are intended to be for use only by jobs themselves, split the interface into "public" and "private" files. Convert blockjobs (e.g. block/backup) to using the private interface. Leave blockdev and others on the public interface. There are remaining uses of private state by qemu-img, and several cases in blockdev.c and block/io.c where we grab job->blk for the purposes of acquiring an AIOContext. These will be corrected in future patches. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-7-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01Blockjobs: Internalize user_pause logicJohn Snow
BlockJobs will begin hiding their state in preparation for some refactorings anyway, so let's internalize the user_pause mechanism instead of leaving it to callers to correctly manage. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-6-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01blockjob: centralize QMP event emissionsJohn Snow
There's no reason to leave this to blockdev; we can do it in blockjobs directly and get rid of an extra callback for most users. All non-internal events, even those created outside of QMP, will consistently emit events. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-5-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01Replication/Blockjobs: Create replication jobs as internalJohn Snow
Bubble up the internal interface to commit and backup jobs, then switch replication tasks over to using this methodology. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-4-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01blockjobs: Allow creating internal jobsJohn Snow
Add the ability to create jobs without an ID. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-3-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01blockjobs: hide internal jobs from management APIJohn Snow
If jobs are not created directly by the user, do not allow them to be seen by the user/management utility. At the moment, 'internal' jobs are those that do not have an ID. As of this patch it is impossible to create such jobs. Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1477584421-1399-2-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-10-31block: Add block_job_add_bdrv()Alberto Garcia
When a block job is created on a certain BlockDriverState, operations are blocked there while the job exists. However, some block jobs may involve additional BDSs, which must be blocked separately when the job is created and unblocked manually afterwards. This patch adds block_job_add_bdrv(), that simplifies this process by keeping a list of BDSs that are involved in the specified block job. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-31block: Add bdrv_drain_all_{begin,end}()Alberto Garcia
bdrv_drain_all() doesn't allow the caller to do anything after all pending requests have been completed but before block jobs are resumed. This patch splits bdrv_drain_all() into _begin() and _end() for that purpose. It also adds aio_{disable,enable}_external() calls to disable external clients in the meantime. An important restriction of this split is that no new block jobs or BlockDriverStates can be created between the bdrv_drain_all_begin() and bdrv_drain_all_end() calls. This is not a concern now because we'll only be using this in bdrv_reopen_multiple(), but it must be dealt with if we ever have other uses cases in the future. Signed-off-by: Alberto Garcia <berto@igalia.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-28aio: convert from RFifoLock to QemuRecMutexPaolo Bonzini
It is simpler and a bit faster, and QEMU does not need the contention callbacks (and thus the fairness) anymore. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1477565348-5458-21-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28iothread: release AioContext around aio_pollPaolo Bonzini
This is the first step towards having fine-grained critical sections in dataplane threads, which will resolve lock ordering problems between address_space_* functions (which need the BQL when doing MMIO, even after we complete RCU-based dispatch) and the AioContext. Because AioContext does not use contention callbacks anymore, the unit test has to be changed. Previously applied as a0710f7995f914e3044e5899bd8ff6c43c62f916 and then reverted. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1477565348-5458-19-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: only call aio_poll on the current thread's AioContextPaolo Bonzini
aio_poll is not thread safe; for example bdrv_drain can hang if the last in-flight I/O operation is completed in the I/O thread after the main thread has checked bs->in_flight. The bug remains latent as long as all of it is called within aio_context_acquire/aio_context_release, but this will change soon. To fix this, if bdrv_drain is called from outside the I/O thread, signal the main AioContext through a dummy bottom half. The event loop then only runs in the I/O thread. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1477565348-5458-18-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: prepare bdrv_reopen_multiple to release AioContextPaolo Bonzini
After the next patch bdrv_drain_all will have to be called without holding any AioContext. Prepare to do this by adding an AioContext argument to bdrv_reopen_multiple. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1477565348-5458-15-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28aio: introduce qemu_get_current_aio_contextPaolo Bonzini
This will be used by BDRV_POLL_WHILE (and thus by bdrv_drain) to choose how to wait for I/O completion. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1477565348-5458-12-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: introduce BDRV_POLL_WHILEPaolo Bonzini
We want the BDS event loop to run exclusively in the iothread that owns the BDS's AioContext. This macro will provide the synchronization between the two event loops; for now it just wraps the common idiom of a while loop around aio_poll. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-Id: <1477565348-5458-8-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: add BDS field to count in-flight requestsPaolo Bonzini
Unlike tracked_requests, this field also counts throttled requests, and remains non-zero if an AIO operation needs a BH to be "really" completed. With this change, it is no longer necessary to have a dummy BdrvTrackedRequest for requests that are never serialising, and it is no longer necessary to poll the AioContext once after bdrv_requests_pending(bs) returns false. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-Id: <1477565348-5458-5-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28blockjob: introduce .drain callback for jobsPaolo Bonzini
This is required to decouple block jobs from running in an AioContext. With multiqueue block devices, a BlockDriverState does not really belong to a single AioContext. The solution is to first wait until all I/O operations are complete; then loop in the main thread for the block job to complete entirely. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-Id: <1477565348-5458-3-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-27block: Remove bdrv_aio_ioctl()Kevin Wolf
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Introduce .bdrv_co_ioctl() driver callbackKevin Wolf
This allows drivers to implement ioctls in a coroutine-based way. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Remove bdrv_ioctl()Kevin Wolf
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Use blk_co_ioctl() for all BB level ioctlsKevin Wolf
All read/write functions already have a single coroutine-based function on the BlockBackend level through which all requests go (no matter what API style the external caller used) and which passes the requests down to the block node level. This patch exports a bdrv_co_ioctl() function and uses it to extend this mode of operation to ioctls. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Remove bdrv_aio_pdiscard()Kevin Wolf
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-24block: More operations for meta dirty bitmapFam Zheng
Callers can create an iterator of meta bitmap with bdrv_dirty_meta_iter_new(), then use the bdrv_dirty_iter_* operations on it. Meta iterators are also counted by bitmap->active_iterators. Also add a couple of functions to retrieve granularity and count. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1476395910-8697-11-git-send-email-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-10-24block: BdrvDirtyBitmap serialization interfaceVladimir Sementsov-Ogievskiy
Several functions to provide necessary access to BdrvDirtyBitmap for block-migration.c Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> [Add the "finish" parameters. - Fam] Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1476395910-8697-9-git-send-email-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-10-24block: Add two dirty bitmap gettersFam Zheng
For dirty bitmap users to get the size and the name of a BdrvDirtyBitmap. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1476395910-8697-6-git-send-email-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-10-24block: Support meta dirty bitmapFam Zheng
The added group of operations enables tracking of the changed bits in the dirty bitmap. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1476395910-8697-5-git-send-email-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-10-24block: Hide HBitmap in block dirty bitmap interfaceFam Zheng
HBitmap is an implementation detail of block dirty bitmap that should be hidden from users. Introduce a BdrvDirtyBitmapIter to encapsulate the underlying HBitmapIter. A small difference in the interface is, before, an HBitmapIter is initialized in place, now the new BdrvDirtyBitmapIter must be dynamically allocated because the structure definition is in block/dirty-bitmap.c. Two current users are converted too. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1476395910-8697-2-git-send-email-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>