similar to: [PATCH v3 0/2] virtio_console: fix replug of virtio console port

This patch series fixes the issue with unplug/replug of a port in virtio console driver which fails with an error "Error allocating inbufs\n". Patch 1 updates the next avail index for packed ring code. Patch 2 makes use of 'virtqueue_detach_unused_buf' function to detach the unused buffers during port hotunplug time. Tested the packed ring code with the qemu virtio 1.1 device

This patch series fixes the issue with unplug/replug of a port in virtio console device, which fails with an error "Error allocating inbufs\n". Patch 2 makes virtio packed ring code compatible with virtio split ring. Tested the packed ring code with the qemu virtio 1.1 device code posted here [1]. Changes from v1[2] ----- Make virtio packed ring code compatible with split ring -

The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset") deffered detaching of unused buffer to virtio device unplug time. This causes unplug/replug of single port in virtio device with an error "Error allocating inbufs\n". As we don't free the unused buffers attached with the port. Re-plug the same port tries to allocate new buffers in virtqueue

The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset") deffered detaching of unused buffer to virtio device unplug time. This causes unplug/replug of single port in virtio device with an error "Error allocating inbufs\n". As we don't free the unused buffers attached with the port. Re-plug the same port tries to allocate new buffers in virtqueue

On Fri, Aug 09, 2019 at 12:18:46PM +0530, Pankaj Gupta wrote: > The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset") > deferred detaching of unused buffer to virtio device unplug time. > This causes unplug/replug of single port in virtio device with an > error "Error allocating inbufs\n". As we don't free the unused buffers > attached with the

On Fri, Aug 09, 2019 at 12:18:46PM +0530, Pankaj Gupta wrote: > The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset") > deferred detaching of unused buffer to virtio device unplug time. > This causes unplug/replug of single port in virtio device with an > error "Error allocating inbufs\n". As we don't free the unused buffers > attached with the

Hello Michael, Thanks for your reply. > > On Mon, Mar 04, 2019 at 06:35:11PM +0530, Pankaj Gupta wrote: > > The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset") > > deffered detaching of unused buffer to virtio device unplug time. > > > > This causes unplug/replug of single port in virtio device with an > > error "Error

Hello Michael, Thanks for your reply. > > On Mon, Mar 04, 2019 at 06:35:11PM +0530, Pankaj Gupta wrote: > > The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset") > > deffered detaching of unused buffer to virtio device unplug time. > > > > This causes unplug/replug of single port in virtio device with an > > error "Error

On Fri, Aug 09, 2019 at 12:18:47PM +0530, Pankaj Gupta wrote: > This patch decrements 'next_avail_idx' count when detaching a buffer > from vq for packed ring code. Split ring code already does this in > virtqueue_detach_unused_buf_split function. This updates the > 'next_avail_idx' to the previous correct index after an unused buffer > is detatched from the vq. >

On 2019/8/9 ??2:48, Pankaj Gupta wrote: > This patch decrements 'next_avail_idx' count when detaching a buffer > from vq for packed ring code. Split ring code already does this in > virtqueue_detach_unused_buf_split function. This updates the > 'next_avail_idx' to the previous correct index after an unused buffer > is detatched from the vq. > > Signed-off-by:

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,\

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,\

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,\

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,\

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,\

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,\

On 06/11/2019 14:56, Michael S. Tsirkin wrote: > On Fri, Oct 18, 2019 at 06:47:18PM +0200, 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,\ >>

On 06/11/2019 14:56, Michael S. Tsirkin wrote: > On Fri, Oct 18, 2019 at 06:47:18PM +0200, 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,\ >>

Turns out virtio console tries to take a buffer out of an active vq. Works by sheer luck, and is explicitly forbidden by spec. And while going over it I saw that error handling is also broken - failure is easy to trigger if I force allocations to fail. Lightly tested. Michael S. Tsirkin (6): virtio_console: don't tie bufs to a vq virtio: add ability to iterate over vqs virtio_console:

Turns out virtio console tries to take a buffer out of an active vq. Works by sheer luck, and is explicitly forbidden by spec. And while going over it I saw that error handling is also broken - failure is easy to trigger if I force allocations to fail. Lightly tested. Michael S. Tsirkin (6): virtio_console: don't tie bufs to a vq virtio: add ability to iterate over vqs virtio_console: