On Tue, 2019-12-03 at 10:42 -0500, Michael S. Tsirkin wrote:
On Tue, Dec 03, 2019 at 03:46:50PM +0100, Amit Shah wrote:
On Thu, 2019-11-14 at 13:25 +0100, Laurent Vivier wrote:
When we hot unplug a virtserialport and then try to hot plug again, it fails:
(qemu) chardev-add socket,id=serial0,path=/tmp/serial0,server,nowait (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ chardev=serial0,id=serial0,name=serial0 (qemu) device_del serial0 (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ chardev=serial0,id=serial0,name=serial0 kernel error: virtio-ports vport2p2: Error allocating inbufs qemu error: virtio-serial-bus: Guest failure in adding port 2 for device \ virtio-serial0.0
This happens because buffers for the in_vq are allocated when the port is added but are not released when the port is unplugged.
They are only released when virtconsole is removed (see a7a69ec0d8e4)
To avoid the problem and to be symmetric, we could allocate all the buffers in init_vqs() as they are released in remove_vqs(), but it sounds like a waste of memory.
Rather than that, this patch changes add_port() logic to ignore ENOSPC error in fill_queue(), which means queue has already been filled.
Fixes: a7a69ec0d8e4 ("virtio_console: free buffers after reset") Cc: mst@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Laurent Vivier lvivier@redhat.com
Reviewed-by: Amit Shah amit@kernel.org
Thanks!
Thanks, however this has already been merged by Linus. I can't add the tag retroactively, sorry about that.
Right, no problem - but I wanted to ensure it's on-list :)
For bugfix patches like that, I think we can reasonably target a turn around of a couple of days, these shouldn't really need to wait weeks for review.
Sure, thanks for picking it up fast enough. Life happens, etc., and it's not always possible to reply in a couple of days. Since we had already covered the main comments in v1 and v2, v3 wasn't going to need much attention anyway.