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| author | Matthew Rosato <mjrosato@linux.ibm.com> | 2020-09-15 15:05:18 -0400 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2020-09-21 14:58:34 -0600 |
| commit | 7d6e1329652ed971d1b6e0e7bea66fba5044e271 (patch) | |
| tree | cc46122738f89fed688be8c3af783ed592a3a3eb /include/uapi | |
| parent | ba4f184e126b751d1bffad5897f263108befc780 (diff) | |
| download | linux-stable-7d6e1329652ed971d1b6e0e7bea66fba5044e271.tar.gz linux-stable-7d6e1329652ed971d1b6e0e7bea66fba5044e271.tar.bz2 linux-stable-7d6e1329652ed971d1b6e0e7bea66fba5044e271.zip | |
vfio iommu: Add dma available capability
Commit 492855939bdb ("vfio/type1: Limit DMA mappings per container")
added the ability to limit the number of memory backed DMA mappings.
However on s390x, when lazy mapping is in use, we use a very large
number of concurrent mappings. Let's provide the current allowable
number of DMA mappings to userspace via the IOMMU info chain so that
userspace can take appropriate mitigation.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/vfio.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 920470502329..3891e03d3af0 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1039,6 +1039,21 @@ struct vfio_iommu_type1_info_cap_migration { __u64 max_dirty_bitmap_size; /* in bytes */ }; +/* + * The DMA available capability allows to report the current number of + * simultaneously outstanding DMA mappings that are allowed. + * + * The structure below defines version 1 of this capability. + * + * avail: specifies the current number of outstanding DMA mappings allowed. + */ +#define VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL 3 + +struct vfio_iommu_type1_info_dma_avail { + struct vfio_info_cap_header header; + __u32 avail; +}; + #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12) /** |