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| author | Matthew Rosato <mjrosato@linux.ibm.com> | 2020-09-15 21:05:18 +0200 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2020-09-21 22:58:34 +0200 |
| commit | 7d6e1329652ed971d1b6e0e7bea66fba5044e271 (patch) | |
| tree | cc46122738f89fed688be8c3af783ed592a3a3eb /drivers/vfio | |
| parent | Linux 5.9-rc6 (diff) | |
| download | linux-7d6e1329652ed971d1b6e0e7bea66fba5044e271.tar.xz linux-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 'drivers/vfio')
| -rw-r--r-- | drivers/vfio/vfio_iommu_type1.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 5fbf0c1f7433..15e21dbffb16 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -2609,6 +2609,20 @@ static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu, return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig)); } +static int vfio_iommu_dma_avail_build_caps(struct vfio_iommu *iommu, + struct vfio_info_cap *caps) +{ + struct vfio_iommu_type1_info_dma_avail cap_dma_avail; + + cap_dma_avail.header.id = VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL; + cap_dma_avail.header.version = 1; + + cap_dma_avail.avail = iommu->dma_avail; + + return vfio_info_add_capability(caps, &cap_dma_avail.header, + sizeof(cap_dma_avail)); +} + static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu, unsigned long arg) { @@ -2642,6 +2656,9 @@ static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu, ret = vfio_iommu_migration_build_caps(iommu, &caps); if (!ret) + ret = vfio_iommu_dma_avail_build_caps(iommu, &caps); + + if (!ret) ret = vfio_iommu_iova_build_caps(iommu, &caps); mutex_unlock(&iommu->lock); |