Detach event channels during drained sections to stop I/O submission
from the ring. xen-block is no longer reliant on aio_disable_external()
after this patch. This will allow us to remove the
aio_disable_external() API once all other code that relies on it is
converted.
Extend xen_device_set_event_channel_context() to allow ctx=NULL. The
event channel still exists but the event loop does not monitor the file
descriptor. Event channel processing can resume by calling
xen_device_set_event_channel_context() with a non-NULL ctx.
Factor out xen_device_set_event_channel_context() calls in
hw/block/dataplane/xen-block.c into attach/detach helper functions.
Incidentally, these don't require the AioContext lock because
aio_set_fd_handler() is thread-safe.
It's safer to register BlockDevOps after the dataplane instance has been
created. The BlockDevOps .drained_begin/end() callbacks depend on the
dataplane instance, so move the blk_set_dev_ops() call after
xen_block_dataplane_create().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230516190238.8401-12-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
A recent Xen commit [1] clarified the semantics of sector based quantities
used in the blkif protocol such that it is now safe to create a xen-block
device with a logical_block_size != 512, as long as the device only
connects to a frontend advertizing 'feature-large-block-size'.
This patch modifies xen-block accordingly. It also uses a stack variable
for the BlockBackend in xen_block_realize() to avoid repeated dereferencing
of the BlockConf pointer, and changes the parameters of
xen_block_dataplane_create() so that the BlockBackend pointer and sector
size are passed expicitly rather than implicitly via the BlockConf.
These modifications have been tested against a recent Windows PV XENVBD
driver [2] using a xen-disk device with a 4kB logical block size.
[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=67e1c050e36b2c9900cca83618e56189effbad98
[2] https://winpvdrvbuild.xenproject.org:8080/job/XENVBD-master/126
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190409164038.25484-1-paul.durrant@citrix.com>
[Edited error message]
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This is a purely cosmetic patch that substitutes the old 'struct XenBlkDev'
name with 'XenBlockDataPlane' and 'blkdev' field/variable names with
'dataplane', and then does necessary fix-up to adhere to coding style.
No functional change.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
This patch adds the transformations necessary to get dataplane/xen-block.c
to build against the new XenBus/XenDevice framework. MAINTAINERS is also
updated due to the introduction of dataplane/xen-block.h.
NOTE: Existing data structure names are retained for the moment. These will
be modified by subsequent patches. A typedef for XenBlockDataPlane
has been added to the header (based on the old struct XenBlkDev name
for the moment) so that the old names don't need to leak out of the
dataplane code.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
