aboutsummaryrefslogtreecommitdiff
path: root/io/channel-file.c
AgeCommit message (Collapse)Author
2022-05-16QIOChannel: Add flags on io_writev and introduce io_flush callbackLeonardo Bras
Add flags to io_writev and introduce io_flush as optional callback to QIOChannelClass, allowing the implementation of zero copy writes by subclasses. How to use them: - Write data using qio_channel_writev*(...,QIO_CHANNEL_WRITE_FLAG_ZERO_COPY), - Wait write completion with qio_channel_flush(). Notes: As some zero copy write implementations work asynchronously, it's recommended to keep the write buffer untouched until the return of qio_channel_flush(), to avoid the risk of sending an updated buffer instead of the buffer state during write. As io_flush callback is optional, if a subclass does not implement it, then: - io_flush will return 0 without changing anything. Also, some functions like qio_channel_writev_full_all() were adapted to receive a flag parameter. That allows shared code between zero copy and non-zero copy writev, and also an easier implementation on new flags. Signed-off-by: Leonardo Bras <leobras@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20220513062836.965425-3-leobras@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-03io: replace qemu_set{_non}block()Marc-André Lureau
Those calls are non-socket fd, or are POSIX-specific. Use the dedicated GLib API. (qemu_set_nonblock() is for socket-like) (this is a preliminary patch before renaming qemu_set_nonblock()) Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2022-01-12aio-posix: split poll check from ready handlerStefan Hajnoczi
Adaptive polling measures the execution time of the polling check plus handlers called when a polled event becomes ready. Handlers can take a significant amount of time, making it look like polling was running for a long time when in fact the event handler was running for a long time. For example, on Linux the io_submit(2) syscall invoked when a virtio-blk device's virtqueue becomes ready can take 10s of microseconds. This can exceed the default polling interval (32 microseconds) and cause adaptive polling to stop polling. By excluding the handler's execution time from the polling check we make the adaptive polling calculation more accurate. As a result, the event loop now stays in polling mode where previously it would have fallen back to file descriptor monitoring. The following data was collected with virtio-blk num-queues=2 event_idx=off using an IOThread. Before: 168k IOPS, IOThread syscalls: 9837.115 ( 0.020 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 16, iocbpp: 0x7fcb9f937db0) = 16 9837.158 ( 0.002 ms): IO iothread1/620155 write(fd: 103, buf: 0x556a2ef71b88, count: 8) = 8 9837.161 ( 0.001 ms): IO iothread1/620155 write(fd: 104, buf: 0x556a2ef71b88, count: 8) = 8 9837.163 ( 0.001 ms): IO iothread1/620155 ppoll(ufds: 0x7fcb90002800, nfds: 4, tsp: 0x7fcb9f1342d0, sigsetsize: 8) = 3 9837.164 ( 0.001 ms): IO iothread1/620155 read(fd: 107, buf: 0x7fcb9f939cc0, count: 512) = 8 9837.174 ( 0.001 ms): IO iothread1/620155 read(fd: 105, buf: 0x7fcb9f939cc0, count: 512) = 8 9837.176 ( 0.001 ms): IO iothread1/620155 read(fd: 106, buf: 0x7fcb9f939cc0, count: 512) = 8 9837.209 ( 0.035 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 32, iocbpp: 0x7fca7d0cebe0) = 32 174k IOPS (+3.6%), IOThread syscalls: 9809.566 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0cdd62be0) = 32 9809.625 ( 0.001 ms): IO iothread1/623061 write(fd: 103, buf: 0x5647cfba5f58, count: 8) = 8 9809.627 ( 0.002 ms): IO iothread1/623061 write(fd: 104, buf: 0x5647cfba5f58, count: 8) = 8 9809.663 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0d0388b50) = 32 Notice that ppoll(2) and eventfd read(2) syscalls are eliminated because the IOThread stays in polling mode instead of falling back to file descriptor monitoring. As usual, polling is not implemented on Windows so this patch ignores the new io_poll_read() callback in aio-win32.c. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Message-id: 20211207132336.36627-2-stefanha@redhat.com [Fixed up aio_set_event_notifier() calls in tests/unit/test-fdmon-epoll.c added after this series was queued. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-10-27io: Fix Lesser GPL version numberChetan Pant
There is no "version 2" of the "Lesser" General Public License. It is either "GPL version 2.0" or "Lesser GPL version 2.1". This patch replaces all occurrences of "Lesser GPL version 2" with "Lesser GPL version 2.1" in comment section. Signed-off-by: Chetan Pant <chetan4windows@gmail.com> Acked-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20201014134033.14095-1-chetan4windows@gmail.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-09-16util: rename qemu_open() to qemu_open_old()Daniel P. Berrangé
We want to introduce a new version of qemu_open() that uses an Error object for reporting problems and make this it the preferred interface. Rename the existing method to release the namespace for the new impl. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-06-12Include qemu/module.h where needed, drop it from qemu-common.hMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190523143508.25387-4-armbru@redhat.com> [Rebased with conflicts resolved automatically, except for hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c; ui/cocoa.m fixed up]
2018-02-15io: Add /dev/fdset/ support to QIOChannelFileRoss Lagerwall
Add /dev/fdset/ support to QIOChannelFile by calling qemu_open() instead of open() and qemu_close() instead of close(). There is a subtle semantic change since qemu_open() automatically sets O_CLOEXEC, but this doesn't affect any of the users of the function. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2018-02-15io: Don't call close multiple times in QIOChannelFileRoss Lagerwall
If the file descriptor underlying QIOChannelFile is closed in the io_close() method, don't close it again in the finalize() method since the file descriptor number may have been reused in the meantime. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2018-02-15io: Fix QIOChannelFile when creating and opening read-writeRoss Lagerwall
The code wrongly passes the mode to open() only if O_WRONLY is set. Instead, the mode should be passed when O_CREAT is set (or O_TMPFILE on Linux). Fix this by always passing the mode since open() will correctly ignore the mode if it is not needed. Add a testcase which exercises this bug and also change the existing testcase to check that the mode of the created file is correct. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2017-02-21io: add methods to set I/O handlers on AioContextPaolo Bonzini
This is in preparation for making qio_channel_yield work on AioContexts other than the main one. Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213135235.12274-6-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-03-22include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-10io: remove checking of EWOULDBLOCKDaniel P. Berrange
Since we now canonicalize WSAEWOULDBLOCK into EAGAIN there is no longer any need to explicitly check EWOULDBLOCK for Win32. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-02-04io: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1454089805-5470-14-git-send-email-peter.maydell@linaro.org
2015-12-18io: add QIOChannelFile classDaniel P. Berrange
Add a QIOChannel subclass that is capable of operating on things that are files, such as plain files, pipes, character/block devices, but notably not sockets. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>