• Lu Baolu's avatar
    iommu/vt-d: Fix kdump kernels boot failure with scalable mode · 0c5f6c0d
    Lu Baolu authored
    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. It needs to work for the old format as well as for the
    extended context entries. As it's hard to find such a common bit for both
    legacy and scalable mode context entries. This replaces it with a per-
    IOMMU bitmap.
    
    Fixes: 7373a8cc ("iommu/vt-d: Setup context and enable RID2PASID support")
    Cc: stable@vger.kernel.org
    Reported-by: default avatarJerry Snitselaar <jsnitsel@redhat.com>
    Tested-by: default avatarWen Jin <wen.jin@intel.com>
    Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
    Link: https://lore.kernel.org/r/20220817011035.3250131-1-baolu.lu@linux.intel.comSigned-off-by: default avatarJoerg Roedel <jroedel@suse.de>
    0c5f6c0d
iommu.c 125 KB