Re: [PATCH v5 16/20] intel_iommu: Set default aw_bits to 48 starting from QEMU 9.2

[Jason Wang]

On Mon, Nov 11, 2024 at 4:39 PM Zhenzhong Duan <zhenzhong.duan@intel.com> wrote:
>
> According to VTD spec, stage-1 page table could support 4-level and
> 5-level paging.
>
> However, 5-level paging translation emulation is unsupported yet.
> That means the only supported value for aw_bits is 48. So default
> aw_bits to 48 in scalable modern mode.
>
> For legacy and scalable legacy modes, 48 is the default choice for
> modern OS when both 48 and 39 are supported. So it makes sense to
> set default to 48 for these two modes too starting from QEMU 9.2.
> Use pc_compat_9_1 to handle the compatibility for machines before
> 9.2.
>
> Suggested-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> Reviewed-by: Clément Mathieu--Drif<clement.mathieu--drif@eviden.com>
> Reviewed-by: Yi Liu <yi.l.liu@intel.com>
> ---

Acked-by: Jason Wang <jasowang@redhat.com>

Thanks