Re: [REWORKED PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL

From: Lu Baolu
Date: Mon May 17 2021 - 03:18:49 EST


Hi Greg,

On 5/17/21 3:07 PM, Greg KH wrote:
On Mon, May 17, 2021 at 11:49:13AM +0800, Lu Baolu wrote:
[ Upstream commit a8ce9ebbecdfda3322bbcece6b3b25888217f8e3 ]

The Access/Dirty bits in the first level page table entry will be set
whenever a page table entry was used for address translation or write
permission was successfully translated. This is always true when using
the first-level page table for kernel IOVA. Instead of wasting hardware
cycles to update the certain bits, it's better to set them up at the
beginning.

Suggested-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@xxxxxxxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/iommu/intel/iommu.c | 14 ++++++++++++--
include/linux/intel-iommu.h | 2 ++
2 files changed, 14 insertions(+), 2 deletions(-)

[Note:
- This is a reworked patch of
https://lore.kernel.org/stable/20210512144819.664462530@xxxxxxxxxxxxxxxxxxx/T/#m65267f0a0091c2fcbde097cea91089775908faad.
- It aims to fix a reported issue of
https://bugzilla.kernel.org/show_bug.cgi?id=213077.
- Please help to review and test.]

What stable tree(s) is this supposed to be for?

It's for 5.10.37.


thanks,

greg k-h


Best regards,
baolu