Re: [PATCH] AMD/IOMMU: drop remaining guest-IOMMU bits too

[Jan Beulich <jbeulich@xxxxxxxx>]

On 20.03.2024 15:06, Roger Pau Monné wrote:
> On Wed, Mar 20, 2024 at 11:58:50AM +0100, Jan Beulich wrote:
>> On 20.03.2024 11:46, Roger Pau Monné wrote:
>>> On Tue, Mar 19, 2024 at 02:28:12PM +0100, Jan Beulich wrote:
>>>> With a02174c6c885 ("amd/iommu: clean up unused guest iommu related
>>>> functions") having removed the sole place where d->g_iommu would be set
>>>> to non-NULL, guest_iommu_add_ppr_log() will unconditionally bail the
>>>> latest from its 2nd if(). With it dropped, all other stuff in the file
>>>> is unused, too. Delete iommu_guest.c altogether.
>>>>
>>>> Further delete struct guest{_buffer,_dev_table,_iommu{,_msi}} as well as
>>>> struct mmio_reg for being unused with the unused g_iommu also dropped
>>>> from struct arch_iommu.
>>>>
>>>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Thanks.

>>>> ---
>>>> I wasn't sure how far to further go with removing the body of
>>>> parse_ppr_log_entry(), or perhaps even the entire function, and then
>>>> further up to all PPR logging code. Hence why for now I've merely
>>>> commented out the function call into the file being deleted (which of
>>>> course Misra isn't going to like). Thoughts / suggestions?
>>>>
>>>> I further wonder whether set_iommu_guest_translation_control() should
>>>> have been invoked independent of guest-IOMMU actually being enabled. IOW
>>>> that may want purging, too. Along these lines iommuv2_enabled may also
>>>> want dropping, for not having any consumer left. Much like has_viommu()
>>>> and then also {XEN_,}X86_EMU_IOMMU, i.e. going as far as affecting the
>>>> public interface.
> 
> I would drop it all.  The public interface part is not stable anyway,
> as it's a domctl, but I would be fine if you want to keep the X86_EMU_IOMMU.

By "all" you also mean the PPR logging code? That's where I felt I might
be going too far ...

Jan