qemu/scsi, branch master

configure, meson: rename targetos to host_os

2023-12-31T08:11:29Z

This variable is about the host OS, not the target. It is used a lot more since the Meson conversion, but the original sin dates back to 2003. Time to fix it. Signed-off-by: Paolo Bonzini

meson: remove OS definitions from config_targetos

2023-12-31T08:11:28Z

CONFIG_DARWIN, CONFIG_LINUX and CONFIG_BSD are used in some rules, but only CONFIG_LINUX has substantial use. Convert them all to if...endif. Signed-off-by: Paolo Bonzini

io: follow coroutine AioContext in qio_channel_yield()

2023-09-08T01:32:11Z

The ongoing QEMU multi-queue block layer effort makes it possible for multiple threads to process I/O in parallel. The nbd block driver is not compatible with the multi-queue block layer yet because QIOChannel cannot be used easily from coroutines running in multiple threads. This series changes the QIOChannel API to make that possible. In the current API, calling qio_channel_attach_aio_context() sets the AioContext where qio_channel_yield() installs an fd handler prior to yielding: qio_channel_attach_aio_context(ioc, my_ctx); ... qio_channel_yield(ioc); // my_ctx is used here ... qio_channel_detach_aio_context(ioc); This API design has limitations: reading and writing must be done in the same AioContext and moving between AioContexts involves a cumbersome sequence of API calls that is not suitable for doing on a per-request basis. There is no fundamental reason why a QIOChannel needs to run within the same AioContext every time qio_channel_yield() is called. QIOChannel only uses the AioContext while inside qio_channel_yield(). The rest of the time, QIOChannel is independent of any AioContext. In the new API, qio_channel_yield() queries the AioContext from the current coroutine using qemu_coroutine_get_aio_context(). There is no need to explicitly attach/detach AioContexts anymore and qio_channel_attach_aio_context() and qio_channel_detach_aio_context() are gone. One coroutine can read from the QIOChannel while another coroutine writes from a different AioContext. This API change allows the nbd block driver to use QIOChannel from any thread. It's important to keep in mind that the block driver already synchronizes QIOChannel access and ensures that two coroutines never read simultaneously or write simultaneously. This patch updates all users of qio_channel_attach_aio_context() to the new API. Most conversions are simple, but vhost-user-server requires a new qemu_coroutine_yield() call to quiesce the vu_client_trip() coroutine when not attached to any AioContext. While the API is has become simpler, there is one wart: QIOChannel has a special case for the iohandler AioContext (used for handlers that must not run in nested event loops). I didn't find an elegant way preserve that behavior, so I added a new API called qio_channel_set_follow_coroutine_ctx(ioc, true|false) for opting in to the new AioContext model. By default QIOChannel uses the iohandler AioHandler. Code that formerly called qio_channel_attach_aio_context() now calls qio_channel_set_follow_coroutine_ctx(ioc, true) once after the QIOChannel is created. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake Acked-by: Daniel P. Berrangé Message-ID: <20230830224802.493686-5-stefanha@redhat.com> [eblake: also fix migration/rdma.c] Signed-off-by: Eric Blake

scsi/qemu-pr-helper: Drop support for 'old' libmultipath API

2023-06-06T08:31:31Z

Commit 1b0578f5c4 ("qemu-pr-helper: Fix build on CentOS 7") added code to probe for 'old' libmultipath API on CentOS 7. However since merge commit 8c345b3e6a (June 2021) we don't build/test CentOS 7 as it felt out of our list of supported distrib versions. Therefore we can safely remove the 'old' API check (mostly reverting commit 1b0578f5c4, except the code got converted to meson in commit 6ec0e15d95 "meson: move libmpathpersist test"). Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20230605174146.87440-2-philmd@linaro.org> Signed-off-by: Paolo Bonzini

qemu-pr-helper: mark more coroutine_fns

2023-04-25T11:17:28Z

do_sgio can suspend via the coroutine function thread_pool_submit_co, so it has to be coroutine_fn as well---and the same is true of all its direct and indirect callers. Signed-off-by: Paolo Bonzini Message-Id: <20230309084456.304669-7-pbonzini@redhat.com> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf

thread-pool: avoid passing the pool parameter every time

2023-04-25T11:17:28Z

thread_pool_submit_aio() is always called on a pool taken from qemu_get_current_aio_context(), and that is the only intended use: each pool runs only in the same thread that is submitting work to it, it can't run anywhere else. Therefore simplify the thread_pool_submit* API and remove the ThreadPool function parameter. Signed-off-by: Emanuele Giuseppe Esposito Message-Id: <20230203131731.851116-5-eesposit@redhat.com> Reviewed-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf

io: Add support for MSG_PEEK for socket channel

2023-02-06T18:22:56Z

MSG_PEEK peeks at the channel, The data is treated as unread and the next read shall still return this data. This support is currently added only for socket class. Extra parameter 'flags' is added to io_readv calls to pass extra read flags like MSG_PEEK. Reviewed-by: Peter Xu Reviewed-by: Daniel P. Berrange Reviewed-by: Juan Quintela Suggested-by: Daniel P. Berrange Signed-off-by: manish.mishra Signed-off-by: Juan Quintela

QIOChannel: Add flags on io_writev and introduce io_flush callback

2022-05-16T12:56:24Z

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 Reviewed-by: Daniel P. Berrangé Reviewed-by: Peter Xu Reviewed-by: Juan Quintela Message-Id: <20220513062836.965425-3-leobras@redhat.com> Signed-off-by: Dr. David Alan Gilbert

util: replace qemu_get_local_state_pathname()

2022-04-21T13:09:09Z

Simplify the function to only return the directory path. Callers are adjusted to use the GLib function to build paths, g_build_filename(). Signed-off-by: Marc-André Lureau Reviewed-by: Daniel P. Berrangé Message-Id: <20220420132624.2439741-39-marcandre.lureau@redhat.com>

include: rename qemu-common.h qemu/help-texts.h

2022-04-21T12:58:24Z

Suggested-by: Peter Maydell Signed-off-by: Marc-André Lureau Reviewed-by: Warner Losh Message-Id: <20220420132624.2439741-7-marcandre.lureau@redhat.com>