linux/kernel/dma
Ashish Kalra e998879d4f x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guests
For SEV, all DMA to and from guest has to use shared (un-encrypted) pages.
SEV uses SWIOTLB to make this happen without requiring changes to device
drivers.  However, depending on the workload being run, the default 64MB
of it might not be enough and it may run out of buffers to use for DMA,
resulting in I/O errors and/or performance degradation for high
I/O workloads.

Adjust the default size of SWIOTLB for SEV guests using a
percentage of the total memory available to guest for the SWIOTLB buffers.

Adds a new sev_setup_arch() function which is invoked from setup_arch()
and it calls into a new swiotlb generic code function swiotlb_adjust_size()
to do the SWIOTLB buffer adjustment.

v5 fixed build errors and warnings as
Reported-by: kbuild test robot <lkp@intel.com>

Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Co-developed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2020-12-11 15:43:41 -05:00
..
coherent.c dma-mapping: split <linux/dma-mapping.h> 2020-10-06 07:07:03 +02:00
contiguous.c dma-mapping updates for 5.10 2020-10-15 14:43:29 -07:00
debug.c dma-mapping: move dma-debug.h to kernel/dma/ 2020-10-06 07:07:05 +02:00
debug.h dma-mapping: move dma-debug.h to kernel/dma/ 2020-10-06 07:07:05 +02:00
direct.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
direct.h dma-mapping: move large parts of <linux/dma-direct.h> to kernel/dma 2020-10-06 07:07:06 +02:00
dummy.c dma-mapping: split <linux/dma-mapping.h> 2020-10-06 07:07:03 +02:00
Kconfig dma-mapping: merge <linux/dma-contiguous.h> into <linux/dma-map-ops.h> 2020-10-06 07:07:04 +02:00
Makefile dma-mapping: move dma_common_{mmap,get_sgtable} out of mapping.c 2020-09-11 09:14:56 +02:00
mapping.c dma-mapping: move large parts of <linux/dma-direct.h> to kernel/dma 2020-10-06 07:07:06 +02:00
ops_helpers.c dma-mapping: merge <linux/dma-noncoherent.h> into <linux/dma-map-ops.h> 2020-10-06 07:07:06 +02:00
pool.c dma-mapping: merge <linux/dma-noncoherent.h> into <linux/dma-map-ops.h> 2020-10-06 07:07:06 +02:00
remap.c dma-mapping: move more functions to dma-map-ops.h 2020-10-20 10:41:07 +02:00
swiotlb.c x86,swiotlb: Adjust SWIOTLB bounce buffer size for SEV guests 2020-12-11 15:43:41 -05:00
virt.c dma-mapping: split <linux/dma-mapping.h> 2020-10-06 07:07:03 +02:00