[PATCH rc 0/8] Add missing cache flush and dirty tracking set for nested parent domain

From: Yi Liu
Date: Thu Feb 08 2024 - 03:23:21 EST

This series adds the missing cache flush and dirty track set for nested
parent domain (it's s2_domain but used as parent) which has no insight
into devices/DID's under the nested domain (a.k.a s1_domain). This
results in missing cache flush per parent domain change and incomplete
dirty tracking set on the parent domain. There was a discussion about
this in the mailing list [1].

This series adds a s1_domains list in the parent domain to track the nested
domains. Hence, the driver can loop the nested domains and use the DIDs of
the nested domain to flush iotlb. The driver can also loop the nested domains
and nested domain's devices list to flush device iotlb and set the dirty
tracking completely.

This series doesn't touch the pasid iotlb or the pasid devtlb as there is
no support of attaching pasid to nested domain yet. It will be covered when
that feature is enabled.

The complete code can be found at[2], this has been tested with a hacky
Qemu[3] to test the unmap on parent domain and dirty tracking set on parent
domain. This just verifies the new path. So appreciated to see t-b with
regression tests.

This aims to the 6.8 rc#, so your special attention is welcomed.

[1] https://lore.kernel.org/linux-iommu/92f8aaca-093d-4161-b8f2-5ab1680df769@xxxxxxxxx/
[2] https://github.com/yiliu1765/iommufd/tree/vtd_nesting_fixes
[3] https://github.com/yiliu1765/qemu/tree/tmp/for-testing-unmap-and-dirty-set-on-parent

base commit: 547ab8fc4cb04a1a6b34377dd8fad34cd2c8a8e3

Yi Liu

Yi Liu (8):
iommu/vt-d: Track nested domains in parent
iommu/vt-d: Add __iommu_flush_iotlb_psi()
iommu/vt-d: Add missing iotlb flush for parent domain
iommu/vt-d: Update iotlb in nested domain attach
iommu/vt-d: Add missing device iotlb flush for parent domain
iommu/vt-d: Remove @domain parameter from
iommu/vt-d: Wrap the dirty tracking loop to be a helper
iommu/vt-d: Add missing dirty tracking set for parent domain

drivers/iommu/intel/iommu.c | 213 ++++++++++++++++++++++++++---------
drivers/iommu/intel/iommu.h | 7 ++
drivers/iommu/intel/nested.c | 12 ++
drivers/iommu/intel/pasid.c | 3 +-
drivers/iommu/intel/pasid.h | 1 -
5 files changed, 182 insertions(+), 54 deletions(-)