On 2022/8/17 09:10, Lu Baolu wrote:
The translation table copying code for kdump kernels is currently based
on the extended root/context entry formats of ECS mode defined in older
VT-d v2.5, and doesn't handle the scalable mode formats. This causes
the kexec capture kernel boot failure with DMAR faults if the IOMMU was
enabled in scalable mode by the previous kernel.
The ECS mode has already been deprecated by the VT-d spec since v3.0 and
Intel IOMMU driver doesn't support this mode as there's no real hardware
implementation. Hence this converts ECS checking in copying table code
into scalable mode.
The existing copying code consumes a bit in the context entry as a mark
of copied entry. This marker needs to work for the old format as well as
for extended context entries. It's hard to find such a bit for both
legacy and scalable mode context entries. This replaces it with a per-
IOMMU bitmap.
Fixes: 7373a8cc38197 ("iommu/vt-d: Setup context and enable RID2PASID support")
Cc:stable@xxxxxxxxxxxxxxx
Reported-by: Jerry Snitselaar<jsnitsel@xxxxxxxxxx>
Tested-by: Wen Jin<wen.jin@xxxxxxxxx>
Signed-off-by: Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>
This patch has been queued:
https://lore.kernel.org/linux-iommu/20220823061557.1631056-1-baolu.lu@xxxxxxxxxxxxxxx/
Best regards,
baolu
