Re: [PATCH] virtio-balloon: Fix page-poison subsection name

[Philippe Mathieu-Daudé]

On 9/14/21 3:17 PM, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> The subsection name for page-poison was typo'd as:
> 
>   vitio-balloon-device/page-poison
> 
> Note the missing 'r' in virtio.
> 
> When we have a machine type that enables page poison, and the guest
> enables it (which needs a new kernel), things fail rather unpredictably.

IIUC since v5.1 guests have 'page-poison'=true but once migrated
they become 'page-poison'=unset=false?

> The fallout from this is that most of the other subsections fail to
> load, including things like the feature bits in the device, one
> possible fallout is that the physical addresses of the queues
> then get aligned differently and we fail with an error about
> last_avail_idx being wrong.
> It's not obvious to me why this doesn't produce a more obvious failure,
> but virtio's vmstate loading is a bit open-coded.

:/

> Fixes: 7483cbbaf82 ("virtio-balloon: Implement support for page poison 
> reporting feature")
> bz: https://bugzilla.redhat.com/show_bug.cgi?id=1984401
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>  hw/virtio/virtio-balloon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
> index 5a69dce35d..c6962fcbfe 100644
> --- a/hw/virtio/virtio-balloon.c
> +++ b/hw/virtio/virtio-balloon.c
> @@ -852,7 +852,7 @@ static const VMStateDescription 
> vmstate_virtio_balloon_free_page_hint = {
>  };
>  
>  static const VMStateDescription vmstate_virtio_balloon_page_poison = {
> -    .name = "vitio-balloon-device/page-poison",
> +    .name = "virtio-balloon-device/page-poison",
>      .version_id = 1,
>      .minimum_version_id = 1,
>      .needed = virtio_balloon_page_poison_support,
>