[PATCH v6 0/9] Fix kdump faults on system with amd iommu
bhe at redhat.com
Thu Oct 20 04:37:11 PDT 2016
This is v6 post.
The principle of the fix is similar to intel iommu. Just defer the assignment
of device to domain to device driver init. But there's difference than
intel iommu. AMD iommu create protection domain and assign device to
domain in iommu driver init stage. So in this patchset I just allow the
assignment of device to domain in software level, but defer updating the
domain info, especially the pte_root to dev table entry to device driver
bnx2 NIC can't reset itself during driver init. Post patch to reset
it during driver init. IO_PAGE_FAULT can't be seen anymore.
Below is link of v5 post.
According to Joerg's comments made several below main changes:
- Add sanity check when copy old dev tables.
- Discard the old patch 6/8.
- If a device is set up with guest translations (DTE.GV=1), then don't
copy that information but move the device over to an empty guest-cr3
table and handle the faults in the PPR log (which just answer them
Issues need be discussed:
- Joerg suggested hooking the behaviour that updates domain info into
dte entry into the set_dma_mask call-back. I tried, but on my local
machine with amd iommu v2, an ohci pci device doesn't call set_dma_mask.
Then IO_PAGE_FAULT printing flooded.
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 11)
- About GCR3 root pointer copying issue, I don't know how to setup the
test environment and haven't tested yet. Hope Joerg or Zongshun can
tell what steps should be taken to test it, or help take a test in your
Baoquan He (9):
iommu/amd: Detect pre enabled translation
iommu/amd: add several helper function
iommu/amd: Define bit fields for DTE particularly
iommu/amd: Add function copy_dev_tables
iommu/amd: copy old trans table from old kernel
iommu/amd: Don't update domain info to dte entry at iommu init stage
iommu/amd: Update domain into to dte entry during device driver init
iommu/amd: Add sanity check of irq remap information of old dev table
iommu/amd: Don't copy GCR3 table root pointer
drivers/iommu/amd_iommu.c | 93 +++++++++++++-------
drivers/iommu/amd_iommu_init.c | 189 +++++++++++++++++++++++++++++++++++++---
drivers/iommu/amd_iommu_proto.h | 2 +
drivers/iommu/amd_iommu_types.h | 53 ++++++++++-
drivers/iommu/amd_iommu_v2.c | 18 +++-
5 files changed, 307 insertions(+), 48 deletions(-)
More information about the kexec