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

[Greg KH]

On Mon, May 17, 2021 at 03:51:13PM +0800, Lu Baolu wrote:
> Hi Greg,
> 
> On 5/17/21 3:27 PM, Greg KH wrote:
> > On Mon, May 17, 2021 at 03:17:53PM +0800, Lu Baolu wrote:
> > > 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.
> > 
> > But the above commit is already in 5.10.y.  And what about 5.11 and
> > 5.12, were those backports incorrect?
> 
> Above commit is now only in v5.10.37. Other 5.10.y are not impacted.
> 
> 5.11 and 5.12 both have correct backports.

Thanks for this, I've reverted the offending commit and added this one
in it's place.

greg k-h