Re: [PATCH 1/2] iommu/vt-d: Fix missing PASID in dev TLB flush with cache_tag_flush_all

[Baolu Lu <baolu.lu@linux.intel.com>]

On 7/11/2025 4:21 PM, Ethan MILON wrote:
> Hi Baolu,
> 
> Thanks for the review.
> 
> On 7/10/25 10:59, Baolu Lu wrote:
>> Caution: External email. Do not open attachments or click links, unless this email comes from a known sender and you know the content is safe.
>>
>>
>> On 7/9/2025 5:48 AM, Ethan MILON wrote:
>>> The function cache_tag_flush_all() was originally implemented with
>>> incorrect device TLB invalidation logic that does not handle PASID, in
>>> commit c4d27ffaa8eb ("iommu/vt-d: Add cache tag invalidation helpers")
>>>
>>> This causes regressions where full address space TLB invalidations occur
>>> with a PASID attached, such as during transparent hugepage unmapping in
>>> SVA configurations or when calling iommu_flush_iotlb_all(). In these
>>> cases, the device receives a TLB invalidation that lacks PASID.
>>>
>>> This incorrect logic was later extracted into
>>> cache_tag_flush_devtlb_all(), in commit 3297d047cd7f ("iommu/vt-d:
>>> Refactor IOTLB and Dev-IOTLB flush for batching")
>>>
>>> The fix replaces the call to cache_tag_flush_devtlb_all() with
>>> cache_tag_flush_devtlb_psi(), which properly handles PASID.
>>>
>>> Fixes: 4f609dbff51b ("iommu/vt-d: Use cache helpers in arch_invalidate_secondary_tlbs")
>>> Fixes: 4e589a53685c ("iommu/vt-d: Use cache_tag_flush_all() in flush_iotlb_all")
>>>
>> Remove above blank line.
> Noted.
> 
>>> Signed-off-by: Ethan Milon<ethan.milon@eviden.com>
>> checkpatch.pl complains:
>>
>> WARNING: From:/Signed-off-by: email name mismatch: 'From: Ethan MILON
>> <ethan.milon@eviden.com>' != 'Signed-off-by: Ethan Milon
>> <ethan.milon@eviden.com>'
> Understood. Our email server seems to overwrite our last names. I’ll
> look into correcting that.
> 
>>> ---
>>>    drivers/iommu/intel/cache.c | 18 +-----------------
>>>    1 file changed, 1 insertion(+), 17 deletions(-)
>> Other looks good to me.
> Should I send a v2 with the fixes?

No. I can change it manually if you have no objection.

Thanks,
baolu