Introduce the aio_add_sqe() API for submitting io_uring requests in the
current AioContext. This allows other components in QEMU, like the block
layer, to take advantage of io_uring features without creating their own
io_uring context.
This API supports nested event loops just like file descriptor
monitoring and BHs do. This comes at a complexity cost: CQE callbacks
must be placed on a list so that nested event loops can invoke pending
CQE callbacks from parent event loops. If you're wondering why
CqeHandler exists instead of just a callback function pointer, this is
why.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-ID: <20251104022933.618123-14-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Introduce qemu_win32_map_alloc() and qemu_win32_map_free() to allocate
shared memory mapping. The handle can be used to share the mapping with
another process.
Teach qemu_create_displaysurface() to allocate shared memory. Following
patches will introduce other places for shared memory allocation.
Other patches for -display dbus will share the memory when possible with
the client, to avoid expensive memory copy between the processes.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230606115658.677673-10-marcandre.lureau@redhat.com>
Devices can pass their MemoryReentrancyGuard (from their DeviceState),
when creating new BHes. Then, the async API will toggle the guard
before/after calling the BH call-back. This prevents bh->mmio reentrancy
issues.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-Id: <20230427211013.2994127-3-alxndr@bu.edu>
[thuth: Fix "line over 90 characters" checkpatch.pl error]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Teach QEMU to use /dev/userfaultfd when it existed and fallback to the
system call if either it's not there or doesn't have enough permission.
Firstly, as long as the app has permission to access /dev/userfaultfd, it
always have the ability to trap kernel faults which QEMU mostly wants.
Meanwhile, in some context (e.g. containers) the userfaultfd syscall can be
forbidden, so it can be the major way to use postcopy in a restricted
environment with strict seccomp setup.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Commit e50caf4a5c ("tracing: convert documentation to rST")
converted docs/devel/tracing.txt to docs/devel/tracing.rst.
We still have several references to the old file, so let's fix them
with the following command:
sed -i s/tracing.txt/tracing.rst/ $(git grep -l docs/devel/tracing.txt)
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210517151702.109066-2-sgarzare@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
We sometime get kernel panic with some devices on Aarch64
hosts. Alex Williamson suggests it might be broken PCIe
root complex. Add trace event to record the latest I/O
access before crashing. In case, assert our accesses are
aligned.
Reviewed-by: Fam Zheng <fam@euphon.net>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20201103020733.2303148-3-philmd@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Some trace points are attributed to the wrong source file. Happens
when we neglect to update trace-events for code motion, or add events
in the wrong place, or misspell the file name.
Clean up with help of scripts/cleanup-trace-events.pl. Funnies
requiring manual post-processing:
* accel/tcg/cputlb.c trace points are in trace-events.
* block.c and blockdev.c trace points are in block/trace-events.
* hw/block/nvme.c uses the preprocessor to hide its trace point use
from cleanup-trace-events.pl.
* hw/tpm/tpm_spapr.c uses pseudo trace point tpm_spapr_show_buffer to
guard debug code.
* include/hw/xen/xen_common.h trace points are in hw/xen/trace-events.
* linux-user/trace-events abbreviates a tedious list of filenames to
*/signal.c.
* net/colo-compare and net/filter-rewriter.c use pseudo trace points
colo_compare_miscompare and colo_filter_rewriter_debug to guard
debug code.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200806141334.3646302-5-armbru@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Some 'qemu_vfio_*' trace events sizes are displayed using
decimal notation, other using hexadecimal notation:
qemu_vfio_ram_block_added s 0xaaaaf2448d90 host 0xffff5bc00000 size 0x4000000
qemu_vfio_dma_map s 0xaaaaf2448d90 host 0xffff5bc00000 size 67108864 temporary 0 iova (nil)
qemu_vfio_find_mapping s 0xaaaaf2448d90 host 0xffff5bc00000
qemu_vfio_new_mapping s 0xaaaaf2448d90 host 0xffff5bc00000 size 67108864 index 4 iova 0x114000
qemu_vfio_do_mapping s 0xaaaaf2448d90 host 0xffff5bc00000 size 67108864 iova 0x114000
As it is hard to follow, unify using hexadecimal for all sizes:
qemu_vfio_ram_block_added s 0xaaaaf1c60d90 host 0xffff2bc00000 size 0x4000000
qemu_vfio_dma_map s 0xaaaaf1c60d90 host 0xffff2bc00000 size 0x4000000 temporary 0 iova (nil)
qemu_vfio_find_mapping s 0xaaaaf1c60d90 host 0xffff2bc00000
qemu_vfio_new_mapping s 0xaaaaf1c60d90 host 0xffff2bc00000 size 0x4000000 index 4 iova 0x114000
qemu_vfio_do_mapping s 0xaaaaf1c60d90 host 0xffff2bc00000 size 0x4000000 iova 0x114000
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Message-Id: <20200820171006.1140228-1-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
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>
Current parameter was always one. We continue with that value for now
in all callers.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
Moved trace to socket_listen
Watch IDs are allocated from incrementing a int counter against
the QFileMonitor object. In very long life QEMU processes with
a huge amount of USB MTP activity creating & deleting directories
it is just about conceivable that the int counter can wrap
around. This would result in incorrect behaviour of the file
monitor watch APIs due to clashing watch IDs.
Instead of trying to detect this situation, this patch changes
the way watch IDs are allocated. It is turned into an int64_t
variable where the high 32 bits are set from the underlying
inotify "int" ID. This gives an ID that is guaranteed unique
for the directory as a whole, and we can rely on the kernel
to enforce this. QFileMonitor then sets the low 32 bits from
a per-directory counter.
The USB MTP device only sets watches on the directory as a
whole, not files within, so there is no risk of guest
triggered wrap around on the low 32 bits.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Some trace points are attributed to the wrong source file. Happens
when we neglect to update trace-events for code motion, or add events
in the wrong place, or misspell the file name.
Clean up with help of cleanup-trace-events.pl. Same funnies as in the
previous commit, of course. Manually shorten its change to
linux-user/trace-events to */signal.c.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20190314180929.27722-6-armbru@redhat.com
Message-Id: <20190314180929.27722-6-armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tracked down with cleanup-trace-events.pl. Funnies requiring manual
post-processing:
* block.c and blockdev.c trace points are in block/trace-events.
* hw/block/nvme.c uses the preprocessor to hide its trace point use
from cleanup-trace-events.pl.
* include/hw/xen/xen_common.h trace points are in hw/xen/trace-events.
* net/colo-compare and net/filter-rewriter.c use pseudo trace points
colo_compare_udp_miscompare and colo_filter_rewriter_debug to guard
debug code.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20190314180929.27722-5-armbru@redhat.com
Message-Id: <20190314180929.27722-5-armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The inotify userspace API for reading events is quite horrible, so it is
useful to wrap it in a more friendly API to avoid duplicating code
across many users in QEMU. Wrapping it also allows introduction of a
platform portability layer, so that we can add impls for non-Linux based
equivalents in future.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This is a preparation for the next patch, and also a very small
optimization. Compute the timeout only once, before invoking
try_poll_mode, and adjust it in run_poll_handlers. The adjustment
is the polling time when polling fails, or zero (non-blocking) if
polling succeeds.
Fixes: 70232b5253
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20180912171040.1732-3-pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
