This is a note to let you know that I've just added the patch titled
iommu/amd: Remove domain_alloc()
to the 6.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-amd-remove-domain_alloc.patch
and it can be found in the queue-6.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d383e5548bcdec90d8c9f51e73b93e4b9c60be60
Author: Jason Gunthorpe <jgg@xxxxxxxx>
Date: Fri Jan 10 12:35:00 2025 -0400
iommu/amd: Remove domain_alloc()
[ Upstream commit f9b80f941e0e68c3347c5d22a17a0f636a064e2c ]
IOMMU drivers should not be sensitive to the domain type, a paging domain
should be created based only on the flags passed in, the same for all
callers.
AMD was using the domain_alloc() path to force VFIO into a v1 domain type,
because v1 gives higher performance. However now that
IOMMU_HWPT_ALLOC_PASID is present, and a NULL device is not possible,
domain_alloc_paging_flags() will do the right thing for VFIO.
When invoked from VFIO flags will be 0 and the amd_iommu_pgtable type of
domain will be selected. This is v1 by default unless the kernel command
line has overridden it to v2.
If the admin is forcing v2 assume they know what they are doing so force
it everywhere, including for VFIO.
Reviewed-by: Vasant Hegde <vasant.hegde@xxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Link: https://lore.kernel.org/r/2-v2-9776c53c2966+1c7-amd_paging_flags_jgg@xxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Stable-dep-of: 082f1bcae8d1 ("iommu/amd: Fully decode all combinations of alloc_paging_flags")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 7e7246c49006a..96d87406f8946 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2386,25 +2386,6 @@ static struct iommu_domain *do_iommu_domain_alloc(unsigned int type,
return &domain->domain;
}
-static struct iommu_domain *amd_iommu_domain_alloc(unsigned int type)
-{
- struct iommu_domain *domain;
- int pgtable = amd_iommu_pgtable;
-
- /*
- * Force IOMMU v1 page table when allocating
- * domain for pass-through devices.
- */
- if (type == IOMMU_DOMAIN_UNMANAGED)
- pgtable = AMD_IOMMU_V1;
-
- domain = do_iommu_domain_alloc(type, NULL, 0, pgtable);
- if (IS_ERR(domain))
- return NULL;
-
- return domain;
-}
-
static struct iommu_domain *
amd_iommu_domain_alloc_paging_flags(struct device *dev, u32 flags,
const struct iommu_user_data *user_data)
@@ -2881,7 +2862,6 @@ const struct iommu_ops amd_iommu_ops = {
.blocked_domain = &blocked_domain,
.release_domain = &release_domain,
.identity_domain = &identity_domain.domain,
- .domain_alloc = amd_iommu_domain_alloc,
.domain_alloc_paging_flags = amd_iommu_domain_alloc_paging_flags,
.domain_alloc_sva = amd_iommu_domain_alloc_sva,
.probe_device = amd_iommu_probe_device,
