Re: [PATCH for-7.1] hw/mips/malta: turn off x86 specific features of PIIX4_PM

[Philippe Mathieu-Daudé]

On Thu, Jul 28, 2022 at 1:50 PM Igor Mammedov <imammedo@redhat.com> wrote:
>
> QEMU crashes trying to save VMSTATE when only MIPS target are compiled in
>   $ qemu-system-mips -monitor stdio
>   (qemu) migrate "exec:gzip -c > STATEFILE.gz"
>   Segmentation fault (core dumped)
>
> It happens due to PIIX4_PM trying to parse hotplug vmstate structures
> which are valid only for x86 and not for MIPS (as it requires ACPI
> tables support which is not existent for ithe later)
>
> Issue was probably exposed by trying to cleanup/compile out unused
> ACPI bits from MIPS target (but forgetting about migration bits).
>
> Disable compiled out features using compat properties as the least
> risky way to deal with issue.
>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> PS:
> another approach could be setting defaults to disabled state and
> enabling them using compat props on PC machines (which is more
> code to deal with => more risky) or continue with PIIX4_PM
> refactoring to split x86-shism out (which I'm not really
> interested in due to risk of regressions for not much of
> benefit)
> ---
>  hw/mips/malta.c | 9 +++++++++
>  1 file changed, 9 insertions(+)

Thanks, queued to mips-fixes.