mbox series

[0/2] s390x/ap: fix hang when mdev attached to guest is removed

Message ID 20230530225544.280031-1-akrowiak@linux.ibm.com (mailing list archive)
Headers show
Series s390x/ap: fix hang when mdev attached to guest is removed | expand

Message

Anthony Krowiak May 30, 2023, 10:55 p.m. UTC 
When a user attempts to remove a vfio-ap mediated device attached to a
guest, the operation hangs until the mdev's fd is closed by the guest
(i.e., the guest is shut down). This patch series provides userspace 
(i.e., qemu) code to handle device unplug requests for AP. When notified
that the mdev is being removed, the handler will unplug the device, thus
avoiding the hang condition.

Tony Krowiak (2):
  linux-headers: Update with vfio_ap IRQ index mapping
  s390x/ap: Wire up the device request notifier interface

 hw/vfio/ap.c               | 113 +++++++++++++++++++++++++++++++++++++
 linux-headers/linux/vfio.h |   9 +++
 2 files changed, 122 insertions(+)

Comments

Anthony Krowiak May 31, 2023, 12:40 p.m. UTC | #1 
The required kernel changes associated with the patch are here:

https://lore.kernel.org/linux-s390/20230530223538.279198-1-akrowiak@linux.ibm.com/

On 5/30/23 6:55 PM, Tony Krowiak wrote:
> When a user attempts to remove a vfio-ap mediated device attached to a
> guest, the operation hangs until the mdev's fd is closed by the guest
> (i.e., the guest is shut down). This patch series provides userspace
> (i.e., qemu) code to handle device unplug requests for AP. When notified
> that the mdev is being removed, the handler will unplug the device, thus
> avoiding the hang condition.
> 
> Tony Krowiak (2):
>    linux-headers: Update with vfio_ap IRQ index mapping
>    s390x/ap: Wire up the device request notifier interface
> 
>   hw/vfio/ap.c               | 113 +++++++++++++++++++++++++++++++++++++
>   linux-headers/linux/vfio.h |   9 +++
>   2 files changed, 122 insertions(+)
>