diff options
| author | Ashish Kalra <ashish.kalra@amd.com> | 2020-12-10 04:25:15 +0300 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2020-12-11 23:43:41 +0300 |
| commit | e998879d4fb7991856916972168cf27c0d86ed12 (patch) | |
| tree | 3bc21e9d11a97ea5c686a917cd03f4835d68d9f5 /include/linux/swiotlb.h | |
| parent | 0477e92881850d44910a7e94fc2c46f96faa131f (diff) | |
| download | linux-e998879d4fb7991856916972168cf27c0d86ed12.tar.xz | |
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>
Diffstat (limited to 'include/linux/swiotlb.h')
| -rw-r--r-- | include/linux/swiotlb.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index fbdc65782195..d9c9fc9ca5d2 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -30,6 +30,9 @@ enum swiotlb_force { */ #define IO_TLB_SHIFT 11 +/* default to 64MB */ +#define IO_TLB_DEFAULT_SIZE (64UL<<20) + extern void swiotlb_init(int verbose); int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose); extern unsigned long swiotlb_nr_tbl(void); @@ -78,6 +81,7 @@ void __init swiotlb_exit(void); unsigned int swiotlb_max_segment(void); size_t swiotlb_max_mapping_size(struct device *dev); bool is_swiotlb_active(void); +void __init swiotlb_adjust_size(unsigned long new_size); #else #define swiotlb_force SWIOTLB_NO_FORCE static inline bool is_swiotlb_buffer(phys_addr_t paddr) @@ -100,6 +104,10 @@ static inline bool is_swiotlb_active(void) { return false; } + +static inline void swiotlb_adjust_size(unsigned long new_size) +{ +} #endif /* CONFIG_SWIOTLB */ extern void swiotlb_print_info(void); |