In current virtio spec, inhdr is a single byte, and is unlikely to
change for both functionality and compatibility considerations.
Non-dataplane uses .in, and we are on the way to converge them. So
let's unify it to get cleaner code.
Remove .inhdr and use .in.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Field "inhdr" is added temporarily for a more mechanical change, and
will be dropped in the next commit.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This will make converging with dataplane code easier.
Add virtio_blk_free_request to handle the freeing of request internal
fields.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For later reusing by dataplane code.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The common logic to process a scsi request in a VirtQueueElement is
extracted to a function to share with dataplane.
This makes VirtIOBlockReq.scsi unused, so drop it.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Today virtio-blk dataplane uses a 1:1 device-per-thread model. Now that
IOThreads have been introduced we can generalize this to N:M devices per
threads.
This patch drops thread code from dataplane in favor of running inside
an IOThread AioContext.
As a bonus we solve the case where a guest keeps submitting I/O requests
while dataplane is trying to stop. Previously the dataplane thread
would continue to process requests until the request gave it a break.
Now we can shut down in bounded time thanks to
aio_context_acquire/release.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The following sequence happens:
- the SeaBIOS virtio-blk driver does not support the WCE feature, which
causes QEMU to disable writeback caching
- the Linux virtio-blk driver resets the device, finds WCE is available
but writeback caching is disabled; tells block layer to not send cache
flush commands
- the Linux virtio-blk driver sets the DRIVER_OK bit, which causes
writeback caching to be re-enabled, but the Linux virtio-blk driver does
not know of this side effect and cache flushes remain disabled
The bug is at the third step. If the guest does know about CONFIG_WCE,
QEMU should ignore the WCE feature's state. The guest will control the
cache mode solely using configuration space. This change makes Linux
do flushes correctly, but Linux will keep SeaBIOS's writethrough mode.
Hence, whenever the guest is reset, the cache mode of the disk should
be reset to whatever was specified in the "-drive" option. With this
change, the Linux virtio-blk driver finds that writeback caching is
enabled, and tells the block layer to send cache flush commands
appropriately.
Reported-by: Rusty Russell <rusty@au1.ibm.com
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Although the dataplane thread does not cooperate with dirty memory
logging yet it's fairly easy to temporarily disable dataplane during
live migration. This way virtio-blk can live migrate when
x-data-plane=on.
The dataplane thread will restart after migration is cancelled or if the
guest resuming virtio-blk operation after migration completes.
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This fix the broken aliases, by renaming the devices.
So: * virtio-blk => virtio-blk-device.
* virtio-balloon => virtio-balloon-device.
* virtio-scsi => virtio-scsi-device.
All virtio-*-pci, virtio-*-s390, virtio-*-ccw didn't change.
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Message-id: 1365501888-14602-1-git-send-email-fred.konrad@greensocs.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Many of these should be cleaned up with proper qdev-/QOM-ification.
Right now there are many catch-all headers in include/hw/ARCH depending
on cpu.h, and this makes it necessary to compile these files per-target.
However, fixing this does not belong in these patches.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
