On 05/09/2022 17:49, Rahul Singh wrote:
Hi Julien,
Hi Rahul,
On 5 Sep 2022, at 5:37 pm, Julien Grall <[email protected]> wrote:
On 05/09/2022 17:30, Rahul Singh wrote:
From: Zhou Wang <[email protected]>
Backport Linux commit a76a37777f2c. Rename __iomb to iomb() while
merging to get in sync with other Xen definitions.
Reading the 'prod' MMIO register in order to determine whether or
not there is valid data beyond 'cons' for a given queue does not
provide sufficient dependency ordering, as the resulting access is
address dependent only on 'cons' and can therefore be speculated
ahead of time, potentially allowing stale data to be read by the
CPU.
Use readl() instead of readl_relaxed() when updating the shadow copy
of the 'prod' pointer, so that all speculated memory reads from the
corresponding queue can occur only from valid slots.
Signed-off-by: Zhou Wang <[email protected]>
Link:
https://lore.kernel.org/r/[email protected]
[will: Use readl() instead of explicit barrier. Update 'cons' side to match.]
Signed-off-by: Will Deacon <[email protected]>
Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
a76a37777f2c
Signed-off-by: Rahul Singh <[email protected]>
---
Changes in v3:
- rename __iomb() to iomb() and also move it from common file to
smmu-v3.c file
Hmmm... Quoting Bertrand:
"We need the __iomb as “linux compatibility” in fact so I would suggest for now to
only introduce it at the beginning of smmu-v3.c with other linux compatibility stuff to
prevent adding this to Xen overall."
Which I also agreed. I couldn't a more recent conversation explaining your
approach. Can you outline why you didn't follow the approached discussed?
I am really sorry that I missed the naming and when I made the patch in my mind
there was a comment from Stefano to
rename the __iomb() to iomb(). I will send only this patch after fixing or do
you want me to send the whole series?
I would be fine if you only resend this patch.
Also, looking at the other patches, you added the Acked-by before your
Signed-off-by. In general, the tags are ordered chronologically, so this
should be inverted. I can deal with that on commit once Bertrand
confirmed he is happy with the series.
Cheers,
--
Julien Grall
