We observed several NVMe failures when running with SWIOTLB. The root
cause of the issue is that when data is mapped via SWIOTLB, the address
offset is not preserved. Several device drivers including the NVMe
driver relies on this offset to function correctly.
Even though we discovered the error when running using AMD SEV, we have
reproduced the same error in Rhel 8 without SEV. By adding swiotlb=force
option to the boot command line parameter, NVMe funcionality is
impacted. For example formatting a disk into xfs format returns an
error.
----
Changes in v2:
Rebased patches to 5.4.115
Updated patch description to correct format.
Jianxiong Gao (9):
driver core: add a min_align_mask field to struct
device_dma_parameters
swiotlb: add a IO_TLB_SIZE define
swiotlb: factor out an io_tlb_offset helper
swiotlb: factor out a nr_slots helper
swiotlb: clean up swiotlb_tbl_unmap_single
swiotlb: refactor swiotlb_tbl_map_single
swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single
swiotlb: respect min_align_mask
nvme-pci: set min_align_mask
drivers/nvme/host/pci.c | 1 +
include/linux/device.h | 1 +
include/linux/dma-mapping.h | 16 +++
include/linux/swiotlb.h | 1 +
kernel/dma/swiotlb.c | 269 ++++++++++++++++++++----------------
5 files changed, 169 insertions(+), 119 deletions(-)
--
2.31.1.751.gd2f1c929bd-goog
