Re: [PATCH v2 5/5] hw: turn off ramfb migration for machines <= 8.1

[Laszlo Ersek <lersek@redhat.com>]

On 10/2/23 13:11, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> For compatibility reasons.
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  hw/core/machine.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 68cb556197..2fa7647422 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -30,7 +30,10 @@
>  #include "hw/virtio/virtio-pci.h"
>  #include "hw/virtio/virtio-net.h"
>  
> -GlobalProperty hw_compat_8_1[] = {};
> +GlobalProperty hw_compat_8_1[] = {
> +    { "ramfb", "migrate", "off" },
> +    { "vfio-pci-nohotplug", "ramfb-migrate", "off" }
> +};
>  const size_t hw_compat_8_1_len = G_N_ELEMENTS(hw_compat_8_1);
>  
>  GlobalProperty hw_compat_8_0[] = {

In the other discussion, you mentioned the concrete reason for this -- I
think if we don't do this, then the ramfb vmstate blocks backward
migration? Can you document the reason here explicitly (commit message,
I mean, doesn't have to be a code comment)?

Thanks!
Laszlo