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* Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into stagingPeter Maydell2020-04-132-1/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bugfixes, and reworking of the atomics documentation. # gpg: Signature made Mon 13 Apr 2020 07:56:22 BST # gpg: using RSA key F13338574B662389866C7682BFFBD25F78C7AE83 # gpg: issuer "pbonzini@redhat.com" # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full] # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full] # 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: module: increase dirs array size by one memory: Do not allow direct write access to rom_device regions vl.c: error out if -mem-path is used together with -M memory-backend rcu: do not mention atomic_mb_read/set in documentation atomics: update documentation atomics: convert to reStructuredText oslib-posix: take lock before qemu_cond_broadcast piix: fix xenfv regression, add compat machine xenfv-4.2 Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| * module: increase dirs array size by oneBruce Rogers2020-04-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | With the module upgrades code change, the statically sized dirs array can now overflow. Increase it's size by one, according to the new maximum possible usage. Fixes: bd83c861c0 ("modules: load modules from versioned /var/run dir") Signed-off-by: Bruce Rogers <brogers@suse.com> Message-Id: <20200411010746.472295-1-brogers@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * oslib-posix: take lock before qemu_cond_broadcastBauerchen2020-04-111-0/+3
| | | | | | | | | | | | | | | | | | | | In touch_all_pages, if the mutex is not taken around qemu_cond_broadcast, qemu_cond_broadcast may be called before all touch page threads enter qemu_cond_wait. In this case, the touch page threads wait forever for the main thread to wake them up, causing a deadlock. Signed-off-by: Bauerchen <bauerchen@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | async: use explicit memory barriersPaolo Bonzini2020-04-093-9/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using C11 atomics, non-seqcst reads and writes do not participate in the total order of seqcst operations. In util/async.c and util/aio-posix.c, in particular, the pattern that we use write ctx->notify_me write bh->scheduled read bh->scheduled read ctx->notify_me if !bh->scheduled, sleep if ctx->notify_me, notify needs to use seqcst operations for both the write and the read. In general this is something that we do not want, because there can be many sources that are polled in addition to bottom halves. The alternative is to place a seqcst memory barrier between the write and the read. This also comes with a disadvantage, in that the memory barrier is implicit on strongly-ordered architectures and it wastes a few dozen clock cycles. Fortunately, ctx->notify_me is never written concurrently by two threads, so we can assert that and relax the writes to ctx->notify_me. The resulting solution works and performs well on both aarch64 and x86. Note that the atomic_set/atomic_read combination is not an atomic read-modify-write, and therefore it is even weaker than C11 ATOMIC_RELAXED; on x86, ATOMIC_RELAXED compiles to a locked operation. Analyzed-by: Ying Fang <fangying1@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Ying Fang <fangying1@huawei.com> Message-Id: <20200407140746.8041-6-pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* | aio-posix: signal-proof fdmon-io_uringStefan Hajnoczi2020-04-091-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The io_uring_enter(2) syscall returns with errno=EINTR when interrupted by a signal. Retry the syscall in this case. It's essential to do this in the io_uring_submit_and_wait() case. My interpretation of the Linux v5.5 io_uring_enter(2) code is that it shouldn't affect the io_uring_submit() case, but there is no guarantee this will always be the case. Let's check for -EINTR around both APIs. Note that the liburing APIs have -errno return values. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20200408091139.273851-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* | linux-user: factor out reading of /proc/self/mapsAlex Bennée2020-04-072-0/+79
|/ | | | | | | | | | | | Unfortunately reading /proc/self/maps is still considered the gold standard for a process finding out about it's own memory layout. As we will want this data in other contexts soon factor out the code to read and parse the data. Rather than just blindly copying the existing sscanf based code we use a more modern glib version of the parsing code to make a more general purpose map structure. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20200403191150.863-9-alex.bennee@linaro.org>
* aio-posix: fix test-aio /aio/event/wait with fdmon-io_uringStefan Hajnoczi2020-04-031-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | When a file descriptor becomes ready we must re-arm POLL_ADD. This is done by adding an sqe to the io_uring sq ring. The ->need_wait() function wasn't taking pending sqes into account and therefore io_uring_submit_and_wait() was not being called. Polling for cqes failed to detect fd readiness since we hadn't submitted the sqe to io_uring. This patch fixes the following tests/test-aio -p /aio/event/wait failure: ok 11 /aio/event/wait ** ERROR:tests/test-aio.c:374:test_flush_event_notifier: assertion failed: (aio_poll(ctx, false)) Reported-by: Cole Robinson <crobinso@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Tested-by: Cole Robinson <crobinso@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20200402145434.99349-1-stefanha@redhat.com Fixes: 73fd282e7b6dd4e4ea1c3bbb3d302c8db51e4ccf ("aio-posix: add io_uring fd monitoring implementation") Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* util/bufferiszero: improve avx2 acceleratorRobert Hoo2020-04-011-17/+9Star
| | | | | | | | | | | | | | By increasing avx2 length_to_accel to 128, we can simplify its logic and reduce a branch. The authorship of this patch actually belongs to Richard Henderson <richard.henderson@linaro.org>, I just fixed a boundary case on his original patch. Suggested-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Message-Id: <1585119021-46593-2-git-send-email-robert.hu@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* util/bufferiszero: assign length_to_accel value for each accelerator caseRobert Hoo2020-04-011-0/+3
| | | | | | | | | Because in unit test, init_accel() will be called several times, each with different accelerator type. Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Message-Id: <1585119021-46593-1-git-send-email-robert.hu@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* aio-posix: fix io_uring with external eventsStefan Hajnoczi2020-03-231-1/+12
| | | | | | | | | | | | | | | | | | | | When external event sources are disabled fdmon-io_uring falls back to fdmon-poll. The ->need_wait() callback needs to watch for this so it can return true when external event sources are disabled. It is also necessary to call ->wait() when AioHandlers have changed because io_uring is asynchronous and we must submit new sqes. Both of these changes to ->need_wait() together fix tests/test-aio -p /aio/external-client, which failed with: test-aio: tests/test-aio.c:404: test_aio_external_client: Assertion `aio_poll(ctx, false)' failed. Reported-by: Julia Suvorova <jusual@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Message-id: 20200319163559.117903-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block/dirty-bitmap: improve _next_dirty_area APIVladimir Sementsov-Ogievskiy2020-03-181-17/+27
| | | | | | | | | | | | | | | | | Firstly, _next_dirty_area is for scenarios when we may contiguously search for next dirty area inside some limited region, so it is more comfortable to specify "end" which should not be recalculated on each iteration. Secondly, let's add a possibility to limit resulting area size, not limiting searching area. This will be used in NBD code in further commit. (Note that now bdrv_dirty_bitmap_next_dirty_area is unused) Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-8-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
* block/dirty-bitmap: add _next_dirty APIVladimir Sementsov-Ogievskiy2020-03-181-28/+32
| | | | | | | | | | | | | | | We have bdrv_dirty_bitmap_next_zero, let's add corresponding bdrv_dirty_bitmap_next_dirty, which is more comfortable to use than bitmap iterators in some cases. For test modify test_hbitmap_next_zero_check_range to check both next_zero and next_dirty and add some new checks. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-7-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
* block/dirty-bitmap: switch _next_dirty_area and _next_zero to int64_tVladimir Sementsov-Ogievskiy2020-03-181-5/+8
| | | | | | | | | | | | | | | | | | | We are going to introduce bdrv_dirty_bitmap_next_dirty so that same variable may be used to store its return value and to be its parameter, so it would int64_t. Similarly, we are going to refactor hbitmap_next_dirty_area to use hbitmap_next_dirty together with hbitmap_next_zero, therefore we want hbitmap_next_zero parameter type to be int64_t too. So, for convenience update all parameters of *_next_zero and *_next_dirty_area to be int64_t. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-6-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
* hbitmap: drop meta bitmaps as they are unusedVladimir Sementsov-Ogievskiy2020-03-181-16/+0Star
| | | | | | | | Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-5-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
* hbitmap: unpublish hbitmap_iter_skip_wordsVladimir Sementsov-Ogievskiy2020-03-181-1/+1
| | | | | | | | | | | Function is internal and even commented as internal. Drop its definition from .h file. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-4-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
* hbitmap: move hbitmap_iter_next_word to hbitmap.cVladimir Sementsov-Ogievskiy2020-03-181-0/+29
| | | | | | | | | | | The function is definitely internal (it's not used by third party and it has complicated interface). Move it to .c file. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-3-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
* hbitmap: assert that we don't create bitmap larger than INT64_MAXVladimir Sementsov-Ogievskiy2020-03-181-0/+2
| | | | | | | | | | | | | | | | | We have APIs which returns signed int64_t, to be able to return error. Therefore we can't handle bitmaps with absolute size larger than (INT64_MAX+1). Still, keep maximum to be INT64_MAX which is a bit safer. Note, that bitmaps are used to represent disk images, which can't exceed INT64_MAX anyway. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20200205112041.6003-2-vsementsov@virtuozzo.com Signed-off-by: John Snow <jsnow@redhat.com>
* lockable: add lock guardsStefan Hajnoczi2020-03-171-12/+11Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces two lock guard macros that automatically unlock a lock object (QemuMutex and others): void f(void) { QEMU_LOCK_GUARD(&mutex); if (!may_fail()) { return; /* automatically unlocks mutex */ } ... } and: WITH_QEMU_LOCK_GUARD(&mutex) { if (!may_fail()) { return; /* automatically unlocks mutex */ } } /* automatically unlocks mutex here */ ... Convert qemu-timer.c functions that benefit from these macros as an example. Manual qemu_mutex_lock/unlock() callers are left unmodified in cases where clarity would not improve by switching to the macros. Many other QemuMutex users remain in the codebase that might benefit from lock guards. Over time they can be converted, if that is desirable. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> [Use QEMU_MAKE_LOCKABLE_NONNULL. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* modules: load modules from versioned /var/run dirChristian Ehrhardt2020-03-161-0/+14
| | | | | | | | | | | | | | | | | | | | | | | On upgrades the old .so files usually are replaced. But on the other hand since a qemu process represents a guest instance it is usually kept around. That makes late addition of dynamic features e.g. 'hot-attach of a ceph disk' fail by trying to load a new version of e.f. block-rbd.so into an old still running qemu binary. This adds a fallback to also load modules from a versioned directory in the temporary /var/run path. That way qemu is providing a way for packaging to store modules of an upgraded qemu package as needed until the next reboot. An example how that can then be used in packaging can be seen in: https://git.launchpad.net/~paelzer/ubuntu/+source/qemu/log/?h=bug-1847361-miss-old-so-on-upgrade-UBUNTU Fixes: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1847361 Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20200310145806.18335-2-christian.ehrhardt@canonical.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* oslib-posix: initialize mutex and condition variablePaolo Bonzini2020-03-161-0/+7
| | | | | | | | | | The mutex and condition variable were never initialized, causing -mem-prealloc to abort with an assertion failure. Fixes: 037fb5eb3941c80a2b7c36a843e47207ddb004d4 Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Cc: bauerchen <bauerchen@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* util: add util function buffer_zero_avx512()Robert Hoo2020-03-161-10/+61
| | | | | | | | | | | | | | And intialize buffer_is_zero() with it, when Intel AVX512F is available on host. This function utilizes Intel AVX512 fundamental instructions which is faster than its implementation with AVX2 (in my unit test, with 4K buffer, on CascadeLake SP, ~36% faster, buffer_zero_avx512() V.S. buffer_zero_avx2()). Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into ↵Peter Maydell2020-03-117-307/+824
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | staging Pull request # gpg: Signature made Wed 11 Mar 2020 12:40:36 GMT # gpg: using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8 # gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full] # gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" [full] # Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8 * remotes/stefanha/tags/block-pull-request: aio-posix: remove idle poll handlers to improve scalability aio-posix: support userspace polling of fd monitoring aio-posix: add io_uring fd monitoring implementation aio-posix: simplify FDMonOps->update() prototype aio-posix: extract ppoll(2) and epoll(7) fd monitoring aio-posix: move RCU_READ_LOCK() into run_poll_handlers() aio-posix: completely stop polling when disabled aio-posix: remove confusing QLIST_SAFE_REMOVE() qemu/queue.h: clear linked list pointers on remove Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| * aio-posix: remove idle poll handlers to improve scalabilityStefan Hajnoczi2020-03-093-7/+90
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there are many poll handlers it's likely that some of them are idle most of the time. Remove handlers that haven't had activity recently so that the polling loop scales better for guests with a large number of devices. This feature only takes effect for the Linux io_uring fd monitoring implementation because it is capable of combining fd monitoring with userspace polling. The other implementations can't do that and risk starving fds in favor of poll handlers, so don't try this optimization when they are in use. IOPS improves from 10k to 105k when the guest has 100 virtio-blk-pci,num-queues=32 devices and 1 virtio-blk-pci,num-queues=1 device for rw=randread,iodepth=1,bs=4k,ioengine=libaio on NVMe. [Clarified aio_poll_handlers locking discipline explanation in comment after discussion with Paolo Bonzini <pbonzini@redhat.com>. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200305170806.1313245-8-stefanha@redhat.com Message-Id: <20200305170806.1313245-8-stefanha@redhat.com>
| * aio-posix: support userspace polling of fd monitoringStefan Hajnoczi2020-03-094-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike ppoll(2) and epoll(7), Linux io_uring completions can be polled from userspace. Previously userspace polling was only allowed when all AioHandler's had an ->io_poll() callback. This prevented starvation of fds by userspace pollable handlers. Add the FDMonOps->need_wait() callback that enables userspace polling even when some AioHandlers lack ->io_poll(). For example, it's now possible to do userspace polling when a TCP/IP socket is monitored thanks to Linux io_uring. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200305170806.1313245-7-stefanha@redhat.com Message-Id: <20200305170806.1313245-7-stefanha@redhat.com>
| * aio-posix: add io_uring fd monitoring implementationStefan Hajnoczi2020-03-094-5/+362
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent Linux io_uring API has several advantages over ppoll(2) and epoll(2). Details are given in the source code. Add an io_uring implementation and make it the default on Linux. Performance is the same as with epoll(7) but later patches add optimizations that take advantage of io_uring. It is necessary to change how aio_set_fd_handler() deals with deleting AioHandlers since removing monitored file descriptors is asynchronous in io_uring. fdmon_io_uring_remove() marks the AioHandler deleted and aio_set_fd_handler() will let it handle deletion in that case. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200305170806.1313245-6-stefanha@redhat.com Message-Id: <20200305170806.1313245-6-stefanha@redhat.com>
| * aio-posix: simplify FDMonOps->update() prototypeStefan Hajnoczi2020-03-093-16/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The AioHandler *node, bool is_new arguments are more complicated to think about than simply being given AioHandler *old_node, AioHandler *new_node. Furthermore, the new Linux io_uring file descriptor monitoring mechanism added by the new patch requires access to both the old and the new nodes. Make this change now in preparation. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200305170806.1313245-5-stefanha@redhat.com Message-Id: <20200305170806.1313245-5-stefanha@redhat.com>
| * aio-posix: extract ppoll(2) and epoll(7) fd monitoringStefan Hajnoczi2020-03-095-274/+330
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ppoll(2) and epoll(7) file descriptor monitoring implementations are mixed with the core util/aio-posix.c code. Before adding another implementation for Linux io_uring, extract out the existing ones so there is a clear interface and the core code is simpler. The new interface is AioContext->fdmon_ops, a pointer to a FDMonOps struct. See the patch for details. Semantic changes: 1. ppoll(2) now reflects events from pollfds[] back into AioHandlers while we're still on the clock for adaptive polling. This was already happening for epoll(7), so if it's really an issue then we'll need to fix both in the future. 2. epoll(7)'s fallback to ppoll(2) while external events are disabled was broken when the number of fds exceeded the epoll(7) upgrade threshold. I guess this code path simply wasn't tested and no one noticed the bug. I didn't go out of my way to fix it but the correct code is simpler than preserving the bug. I also took some liberties in removing the unnecessary AioContext->epoll_available (just check AioContext->epollfd != -1 instead) and AioContext->epoll_enabled (it's implicit if our AioContext->fdmon_ops callbacks are being invoked) fields. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200305170806.1313245-4-stefanha@redhat.com Message-Id: <20200305170806.1313245-4-stefanha@redhat.com>
| * aio-posix: move RCU_READ_LOCK() into run_poll_handlers()Stefan Hajnoczi2020-03-091-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | Now that run_poll_handlers_once() is only called by run_poll_handlers() we can improve the CPU time profile by moving the expensive RCU_READ_LOCK() out of the polling loop. This reduces the run_poll_handlers() from 40% CPU to 10% CPU in perf's sampling profiler output. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200305170806.1313245-3-stefanha@redhat.com Message-Id: <20200305170806.1313245-3-stefanha@redhat.com>
| * aio-posix: completely stop polling when disabledStefan Hajnoczi2020-03-091-7/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One iteration of polling is always performed even when polling is disabled. This is done because: 1. Userspace polling is cheaper than making a syscall. We might get lucky. 2. We must poll once more after polling has stopped in case an event occurred while stopping polling. However, there are downsides: 1. Polling becomes a bottleneck when the number of event sources is very high. It's more efficient to monitor fds in that case. 2. A high-frequency polling event source can starve non-polling event sources because ppoll(2)/epoll(7) is never invoked. This patch removes the forced polling iteration so that poll_ns=0 really means no polling. IOPS increases from 10k to 60k when the guest has 100 virtio-blk-pci,num-queues=32 devices and 1 virtio-blk-pci,num-queues=1 device because the large number of event sources being polled slows down the event loop. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200305170806.1313245-2-stefanha@redhat.com Message-Id: <20200305170806.1313245-2-stefanha@redhat.com>
| * aio-posix: remove confusing QLIST_SAFE_REMOVE()Stefan Hajnoczi2020-03-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | QLIST_SAFE_REMOVE() is confusing here because the node must be on the list. We actually just wanted to clear the linked list pointers when removing it from the list. QLIST_REMOVE() now does this, so switch to it. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Link: https://lore.kernel.org/r/20200224103406.1894923-3-stefanha@redhat.com Message-Id: <20200224103406.1894923-3-stefanha@redhat.com>
* | util/osdep: Improve error report by calling error_setg_win32()Philippe Mathieu-Daudé2020-03-091-2/+2
|/ | | | | | | | | Use error_setg_win32() which adds a hint similar to strerror(errno)). Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20200228100726.8414-3-philmd@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
* mem-prealloc: optimize large guest startupbauerchen2020-02-251-8/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [desc]: Large memory VM starts slowly when using -mem-prealloc, and there are some areas to optimize in current method; 1、mmap will be used to alloc threads stack during create page clearing threads, and it will attempt mm->mmap_sem for write lock, but clearing threads have hold read lock, this competition will cause threads createion very slow; 2、methods of calcuating pages for per threads is not well;if we use 64 threads to split 160 hugepage,63 threads clear 2page,1 thread clear 34 page,so the entire speed is very slow; to solve the first problem,we add a mutex in thread function,and start all threads when all threads finished createion; and the second problem, we spread remainder to other threads,in situation that 160 hugepage and 64 threads, there are 32 threads clear 3 pages,and 32 threads clear 2 pages. [test]: 320G 84c VM start time can be reduced to 10s 680G 84c VM start time can be reduced to 18s Signed-off-by: bauerchen <bauerchen@tencent.com> Reviewed-by: Pan Rui <ruippan@tencent.com> Reviewed-by: Ivan Ren <ivanren@tencent.com> [Simplify computation of the number of pages per thread. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* module: check module wasn't already initializedAlexander Bulekov2020-02-221-0/+7
| | | | | | | | | | | | | | | The virtual-device fuzzer must initialize QOM, prior to running vl:qemu_init, so that it can use the qos_graph to identify the arguments required to initialize a guest for libqos-assisted fuzzing. This change prevents errors when vl:qemu_init tries to (re)initialize the previously initialized QOM module. Signed-off-by: Alexander Bulekov <alxndr@bu.edu> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20200220041118.23264-4-alxndr@bu.edu Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* aio-posix: make AioHandler dispatch O(1) with epollStefan Hajnoczi2020-02-221-32/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | File descriptor monitoring is O(1) with epoll(7), but aio_dispatch_handlers() still scans all AioHandlers instead of dispatching just those that are ready. This makes aio_poll() O(n) with respect to the total number of registered handlers. Add a local ready_list to aio_poll() so that each nested aio_poll() builds a list of handlers ready to be dispatched. Since file descriptor polling is level-triggered, nested aio_poll() calls also see fds that were ready in the parent but not yet dispatched. This guarantees that nested aio_poll() invocations will dispatch all fds, even those that became ready before the nested invocation. Since only handlers ready to be dispatched are placed onto the ready_list, the new aio_dispatch_ready_handlers() function provides O(1) dispatch. Note that AioContext polling is still O(n) and currently cannot be fully disabled. This still needs to be fixed before aio_poll() is fully O(1). Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Sergio Lopez <slp@redhat.com> Message-id: 20200214171712.541358-6-stefanha@redhat.com [Fix compilation error on macOS where there is no epoll(87). The aio_epoll() prototype was out of date and aio_add_ready_list() needed to be moved outside the ifdef. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* aio-posix: make AioHandler deletion O(1)Stefan Hajnoczi2020-02-221-18/+35
| | | | | | | | | | | | | | It is not necessary to scan all AioHandlers for deletion. Keep a list of deleted handlers instead of scanning the full list of all handlers. The AioHandler->deleted field can be dropped. Let's check if the handler has been inserted into the deleted list instead. Add a new QLIST_IS_INSERTED() API for this check. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Sergio Lopez <slp@redhat.com> Message-id: 20200214171712.541358-5-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* aio-posix: don't pass ns timeout to epoll_wait()Stefan Hajnoczi2020-02-221-0/+3
| | | | | | | | | | | | | | Don't pass the nanosecond timeout into epoll_wait(), which expects milliseconds. The epoll_wait() timeout value does not matter if qemu_poll_ns() determined that the poll fd is ready, but passing a value in the wrong units is still ugly. Pass a 0 timeout to epoll_wait() instead. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Sergio Lopez <slp@redhat.com> Message-id: 20200214171712.541358-3-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* aio-posix: fix use after leaving scope in aio_poll()Stefan Hajnoczi2020-02-221-12/+8Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | epoll_handler is a stack variable and must not be accessed after it goes out of scope: if (aio_epoll_check_poll(ctx, pollfds, npfd, timeout)) { AioHandler epoll_handler; ... add_pollfd(&epoll_handler); ret = aio_epoll(ctx, pollfds, npfd, timeout); } ... ... /* if we have any readable fds, dispatch event */ if (ret > 0) { for (i = 0; i < npfd; i++) { nodes[i]->pfd.revents = pollfds[i].revents; } } nodes[0] is &epoll_handler, which has already gone out of scope. There is no need to use pollfds[] for epoll. We don't need an AioHandler for the epoll fd. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Sergio Lopez <slp@redhat.com> Message-id: 20200214171712.541358-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* util/async: make bh_aio_poll() O(1)Stefan Hajnoczi2020-02-221-99/+138
| | | | | | | | | | | | | | | | | | | | | | | | | | The ctx->first_bh list contains all created BHs, including those that are not scheduled. The list is iterated by the event loop and therefore has O(n) time complexity with respected to the number of created BHs. Rewrite BHs so that only scheduled or deleted BHs are enqueued. Only BHs that actually require action will be iterated. One semantic change is required: qemu_bh_delete() enqueues the BH and therefore invokes aio_notify(). The tests/test-aio.c:test_source_bh_delete_from_cb() test case assumed that g_main_context_iteration(NULL, false) returns false after qemu_bh_delete() but it now returns true for one iteration. Fix up the test case. This patch makes aio_compute_timeout() and aio_bh_poll() drop from a CPU profile reported by perf-top(1). Previously they combined to 9% CPU utilization when AioContext polling is commented out and the guest has 2 virtio-blk,num-queues=1 and 99 virtio-blk,num-queues=32 devices. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20200221093951.1414693-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* aio-posix: avoid reacquiring rcu_read_lock() when pollingStefan Hajnoczi2020-02-221-0/+11
| | | | | | | | | | | | | The first rcu_read_lock/unlock() is expensive. Nested calls are cheap. This optimization increases IOPS from 73k to 162k with a Linux guest that has 2 virtio-blk,num-queues=1 and 99 virtio-blk,num-queues=32 devices. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20200218182708.914552-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.0-20200221' ↵Peter Maydell2020-02-212-0/+30
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | into staging ppc patch queue 2020-02-21 Here's the next patch of ppc target patches. Highlights are: * Some fixes for CAS / unplug interactions * Remove some leaks of device trees * Some fixes for the PHB3 and PHB4 devices * Support for NVDIMMs on the pseries machine type * Assorted other fixes and cleanups # gpg: Signature made Fri 21 Feb 2020 03:35:40 GMT # gpg: using RSA key 75F46586AE61A66CC44E87DC6C38CACA20D9B392 # gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>" [full] # gpg: aka "David Gibson (Red Hat) <dgibson@redhat.com>" [full] # gpg: aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>" [full] # gpg: aka "David Gibson (kernel.org) <dwg@kernel.org>" [unknown] # Primary key fingerprint: 75F4 6586 AE61 A66C C44E 87DC 6C38 CACA 20D9 B392 * remotes/dgibson/tags/ppc-for-5.0-20200221: hw/ppc/virtex_ml507:fix leak of fdevice tree blob spapr: Fix handling of unplugged devices during CAS and migration spapr: Don't use spapr_drc_needed() in CAS code ppc: free 'fdt' after reset the machine target/ppc/cpu.h: Clean up comments in the struct CPUPPCState definition target/ppc/cpu.h: Move fpu related members closer in cpu env target/ppc: Fix typo in comments spapr: Allow changing offset for -kernel image pnv/phb3: Add missing break statement pnv/phb4: Fix error path in pnv_pec_realize() pnv/phb3: Convert 1u to 1ull target/ppc/cpu.h: Remove duplicate includes spapr: Add Hcalls to support PAPR NVDIMM device spapr: Add NVDIMM device support nvdimm: add uuid property to nvdimm mem: move nvdimm_device_list to utilities ppc: function to setup latest class options ppc/pnv: Fix PCI_EXPRESS dependency qtest: Fix rtas dependencies spapr/rtas: Print message from "ibm,os-term" Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| * mem: move nvdimm_device_list to utilitiesShivaprasad G Bhat2020-02-202-0/+30
| | | | | | | | | | | | | | | | | | | | | | nvdimm_device_list is required for parsing the list for devices in subsequent patches. Move it to common utility area. Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Message-Id: <158131055857.2897.15658377276504711773.stgit@lep8c.aus.stglabs.ibm.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
* | Merge remote-tracking branch ↵Peter Maydell2020-02-201-0/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'remotes/vivier2/tags/linux-user-for-5.0-pull-request' into staging Implement membarrier, SO_RCVTIMEO and SO_SNDTIMEO Disable by default build of fdt, slirp and tools with linux-user Improve strace and use qemu_log to send trace to a file Add partial ALSA ioctl supports # gpg: Signature made Thu 20 Feb 2020 09:20:20 GMT # gpg: using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C # gpg: issuer "laurent@vivier.eu" # gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full] # gpg: aka "Laurent Vivier <laurent@vivier.eu>" [full] # gpg: aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full] # Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F 5173 F30C 38BD 3F2F BE3C * remotes/vivier2/tags/linux-user-for-5.0-pull-request: linux-user: Add support for selected alsa timer instructions using ioctls linux-user: Add support for getting/setting selected alsa timer parameters using ioctls linux-user: Add support for selecting alsa timer using ioctl linux-user: Add support for getting/setting specified alsa timer parameters using ioctls linux-user: Add support for getting alsa timer version and id linux-user: remove gemu_log from the linux-user tree linux-user: Use `qemu_log' for strace linux-user: Use `qemu_log' for non-strace logging configure: Avoid compiling system tools on user build by default linux-user/strace: Improve output of various syscalls configure: linux-user doesn't need neither fdt nor slirp linux-user: implement getsockopt SO_RCVTIMEO and SO_SNDTIMEO linux-user: Implement membarrier syscall Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| * linux-user: Use `qemu_log' for straceJosh Kunz2020-02-191-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change switches linux-user strace logging to use the newer `qemu_log` logging subsystem rather than the older `gemu_log` (notice the "g") logger. `qemu_log` has several advantages, namely that it allows logging to a file, and provides a more unified interface for configuration of logging (via the QEMU_LOG environment variable or options). This change introduces a new log mask: `LOG_STRACE` which is used for logging of user-mode strace messages. Reviewed-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Josh Kunz <jkz@google.com> Message-Id: <20200204025416.111409-3-jkz@google.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
* | Report stringified errno in VFIO related errorsMichal Privoznik2020-02-181-3/+3
|/ | | | | | | | | | | | | | | In a few places we report errno formatted as a negative integer. This is not as user friendly as it can be. Use strerror() and/or error_setg_errno() instead. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Message-Id: <4949c3ecf1a32189b8a4b5eb4b0fd04c1122501d.1581674006.git.mprivozn@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
* Remove support for CLOCK_MONOTONIC not being definedPeter Maydell2020-02-121-7/+4Star
| | | | | | | | | | | | | | | | | | Some older parts of QEMU's codebase assume that CLOCK_MONOTONIC might not be defined by the host OS, and have workarounds to deal with this. However, more recently (notably in commit 50290c002c045280f8d for qemu-img in mid-2019, but also much earlier in 2011 in commit 22795174a37e0 for ui/spice-display.c) we've written code that assumes CLOCK_MONOTONIC is always defined. The only host OS anybody's ever noticed this on is OSX 10.11 and earlier, which we don't support. So we can assume that all our host OSes have the #define, and we can remove some now-unnecessary ifdefs. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20200201172252.6605-1-peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' ↵Peter Maydell2020-01-311-12/+16
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | into staging Pull request # gpg: Signature made Thu 30 Jan 2020 21:38:06 GMT # gpg: using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8 # gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full] # gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" [full] # Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8 * remotes/stefanha/tags/tracing-pull-request: qemu_set_log_filename: filename argument may be NULL hw/display/qxl.c: Use trace_event_get_state_backends() memory.c: Use trace_event_get_state_backends() docs/devel/tracing.txt: Recommend only trace_event_get_state_backends() Makefile: Keep trace-events-subdirs ordered Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| * qemu_set_log_filename: filename argument may be NULLSalvador Fandino2020-01-301-12/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | NULL is a valid log filename used to indicate we want to use stderr but qemu_set_log_filename (which is called by bsd-user/main.c) was not handling it correctly. That also made redundant a couple of NULL checks in calling code which have been removed. Signed-off-by: Salvador Fandino <salvador@qindel.com> Message-Id: <20200123193626.19956-1-salvador@qindel.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* | util/async: add aio interfaces for io_uringAarushi Mehta2020-01-301-0/+36
|/ | | | | | | | | Signed-off-by: Aarushi Mehta <mehta.aaru20@gmail.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20200120141858.587874-7-stefanha@redhat.com Message-Id: <20200120141858.587874-7-stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* util/cacheinfo: fix crash when compiling with uClibcCarlos Santos2020-01-221-2/+8
| | | | | | | | | | | | | uClibc defines _SC_LEVEL1_ICACHE_LINESIZE and _SC_LEVEL1_DCACHE_LINESIZE but the corresponding sysconf calls returns -1, which is a valid result, meaning that the limit is indeterminate. Handle this situation using the fallback values instead of crashing due to an assertion failure. Signed-off-by: Carlos Santos <casantos@redhat.com> Message-Id: <20191017123713.30192-1-casantos@redhat.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
* Merge remote-tracking branch ↵Peter Maydell2020-01-131-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'remotes/vivier2/tags/trivial-branch-pull-request' into staging Fix some uninitialized variable warnings, some memory leak warnings and update MAINTAINERS file. # gpg: Signature made Wed 08 Jan 2020 16:02:11 GMT # gpg: using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C # gpg: issuer "laurent@vivier.eu" # gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full] # gpg: aka "Laurent Vivier <laurent@vivier.eu>" [full] # gpg: aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full] # Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F 5173 F30C 38BD 3F2F BE3C * remotes/vivier2/tags/trivial-branch-pull-request: vl: fix memory leak in configure_accelerators arm/translate-a64: fix uninitialized variable warning nbd: fix uninitialized variable warning util/module: fix a memory leak MAINTAINERS: Update Yuval Shaia's email address Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-12-05 02:48:11 +0100