Re: [RFC] vhost: Clear the pending messages on vhost_init_device_iotlb()

Michael S. Tsirkin
2022-11-07T20:43:19Z

On Mon, Nov 07, 2022 at 09:34:31PM +0100, Eric Auger wrote:
> When the vhost iotlb is used along with a guest virtual iommu
> and the guest gets rebooted, some MISS messages may have been
> recorded just before the reboot and spuriously executed by
> the virtual iommu after the reboot. Despite the device iotlb gets
> re-initialized, the messages are not cleared. Fix that by calling
> vhost_clear_msg() at the end of vhost_init_device_iotlb().
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> ---
> drivers/vhost/vhost.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 40097826cff0..422a1fdee0ca 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -1751,6 +1751,7 @@ int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled)
> }
>
> vhost_iotlb_free(oiotlb);
> + vhost_clear_msg(d);
>
> return 0;
> }

Hmm. Can't messages meanwhile get processes and affect the
new iotlb?

> --
> 2.37.3