thread-pool: avoid passing the pool parameter every time

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 r

thread-pool: avoid passing the pool parameter every time

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 <eesposit@redhat.com>
Message-Id: <20230203131731.851116-5-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

thread-pool: avoid passing the pool parameter every time

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 r

thread-pool: avoid passing the pool parameter every time

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 <eesposit@redhat.com>
Message-Id: <20230203131731.851116-5-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

thread-pool: avoid passing the pool parameter every time

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 r

thread-pool: avoid passing the pool parameter every time

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 <eesposit@redhat.com>
Message-Id: <20230203131731.851116-5-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qapi: Use QAPI_LIST_APPEND in trivial cases

The easiest spots to use QAPI_LIST_APPEND are where we already have an
obvious pointer to the tail of a list. While at it, consistently use
the variable

qapi: Use QAPI_LIST_APPEND in trivial cases

The easiest spots to use QAPI_LIST_APPEND are where we already have an
obvious pointer to the tail of a list. While at it, consistently use
the variable name 'tail' for that purpose.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210113221013.390592-5-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qom: Change object_get_canonical_path_component() not to malloc

object_get_canonical_path_component() returns a malloced copy of a
property name on success, null on failure.

19 of its 25 callers im

qom: Change object_get_canonical_path_component() not to malloc

object_get_canonical_path_component() returns a malloced copy of a
property name on success, null on failure.

19 of its 25 callers immediately free the returned copy.

Change object_get_canonical_path_component() to return the property
name directly. Since modifying the name would be wrong, adjust the
return type to const char *.

Drop the free from the 19 callers become simpler, add the g_strdup()
to the other six.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-4-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>

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pr-manager: Fix invalid g_free() crash bug

pr_manager_worker() passes its @opaque argument to g_free(). Wrong;
it points to pr_manager_worker()'s automatic @data. Broken when
commit 2f3a7ab39be co

pr-manager: Fix invalid g_free() crash bug

pr_manager_worker() passes its @opaque argument to g_free(). Wrong;
it points to pr_manager_worker()'s automatic @data. Broken when
commit 2f3a7ab39be converted @data from heap- to stack-allocated. Fix
by deleting the g_free().

Fixes: 2f3a7ab39bec4ba8022dc4d42ea641165b004e3e
Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

Include qemu/module.h where needed, drop it from qemu-common.h

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts res

Include qemu/module.h where needed, drop it from qemu-common.h

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]

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file-posix: Switch to .bdrv_co_ioctl

No real reason to keep using the callback based mechanism here when the
rest of the file-posix driver is coroutine based. Changing it brings
ioctls more in line

file-posix: Switch to .bdrv_co_ioctl

No real reason to keep using the callback based mechanism here when the
rest of the file-posix driver is coroutine based. Changing it brings
ioctls more in line with how other request types work.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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pr-manager: add query-pr-managers QMP command

This command lets you query the connection status of each pr-manager-helper
object.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

scsi, file-posix: add support for persistent reservation management

It is a common requirement for virtual machine to send persistent
reservations, but this currently requires either running QEMU wi

scsi, file-posix: add support for persistent reservation management

It is a common requirement for virtual machine to send persistent
reservations, but this currently requires either running QEMU with
CAP_SYS_RAWIO, or using out-of-tree patches that let an unprivileged
QEMU bypass Linux's filter on SG_IO commands.

As an alternative mechanism, the next patches will introduce a
privileged helper to run persistent reservation commands without
expanding QEMU's attack surface unnecessarily.

The helper is invoked through a "pr-manager" QOM object, to which
file-posix.c passes SG_IO requests for PERSISTENT RESERVE OUT and
PERSISTENT RESERVE IN commands. For example:

$ qemu-system-x86_64
-device virtio-scsi \
-object pr-manager-helper,id=helper0,path=/var/run/qemu-pr-helper.sock
-drive if=none,id=hd,driver=raw,file.filename=/dev/sdb,file.pr-manager=helper0
-device scsi-block,drive=hd

or:

$ qemu-system-x86_64
-device virtio-scsi \
-object pr-manager-helper,id=helper0,path=/var/run/qemu-pr-helper.sock
-blockdev node-name=hd,driver=raw,file.driver=host_device,file.filename=/dev/sdb,file.pr-manager=helper0
-device scsi-block,drive=hd

Multiple pr-manager implementations are conceivable and possible, though
only one is implemented right now. For example, a pr-manager could:

- talk directly to the multipath daemon from a privileged QEMU
(i.e. QEMU links to libmpathpersist); this makes reservation work
properly with multipath, but still requires CAP_SYS_RAWIO

- use the Linux IOC_PR_* ioctls (they require CAP_SYS_ADMIN though)

- more interestingly, implement reservations directly in QEMU
through file system locks or a shared database (e.g. sqlite)

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...