[ Upstream commit a45dd34663 ]
A vSTE may have three configuration types: Abort, Bypass, and Translate.
An Abort vSTE wouldn't enable ATS, but the other two might.
It makes sense for a Transalte vSTE to rely on the guest vSTE.EATS field.
For a Bypass vSTE, it would end up with an S2-only physical STE, similar
to an attachment to a regular S2 domain. However, the nested case always
disables ATS following the Bypass vSTE, while the regular S2 case always
enables ATS so long as arm_smmu_ats_supported(master) == true.
Note that ATS is needed for certain VM centric workloads and historically
non-vSMMU cases have relied on this automatic enablement. So, having the
nested case behave differently causes problems.
To fix that, add a condition to disable_ats, so that it might enable ATS
for a Bypass vSTE, aligning with the regular S2 case.
Fixes: f27298a82b ("iommu/arm-smmu-v3: Allow ATS for IOMMU_DOMAIN_NESTED")
Cc: stable@vger.kernel.org
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
a50006e7ba