From e6147c5a23a75361b1374bfb4b96403d243b5c38 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Tue, 19 Jan 2021 12:50:43 -0500 Subject: [PATCH 4/7] vfio: Find DMA available capability RH-Author: Cornelia Huck Message-id: <20210119125046.472811-5-cohuck@redhat.com> Patchwork-id: 100677 O-Subject: [RHEL-8.4.0 qemu-kvm PATCH 4/7] vfio: Find DMA available capability Bugzilla: 1905391 RH-Acked-by: David Hildenbrand RH-Acked-by: Auger Eric RH-Acked-by: Thomas Huth From: Matthew Rosato The underlying host may be limiting the number of outstanding DMA requests for type 1 IOMMU. Add helper functions to check for the DMA available capability and retrieve the current number of DMA mappings allowed. Signed-off-by: Matthew Rosato Reviewed-by: Cornelia Huck [aw: vfio_get_info_dma_avail moved inside CONFIG_LINUX] Signed-off-by: Alex Williamson (cherry picked from commit 7486a62845b1e12011dd99973e4739f69d57cd38) Signed-off-by: Cornelia Huck Signed-off-by: Danilo C. L. de Paula --- hw/vfio/common.c | 31 +++++++++++++++++++++++++++++++ include/hw/vfio/vfio-common.h | 2 ++ 2 files changed, 33 insertions(+) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 77d62d2dcdf..23efdfadebd 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -850,6 +850,37 @@ vfio_get_region_info_cap(struct vfio_region_info *info, uint16_t id) return vfio_get_cap((void *)info, info->cap_offset, id); } +static struct vfio_info_cap_header * +vfio_get_iommu_type1_info_cap(struct vfio_iommu_type1_info *info, uint16_t id) +{ + if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) { + return NULL; + } + + return vfio_get_cap((void *)info, info->cap_offset, id); +} + +bool vfio_get_info_dma_avail(struct vfio_iommu_type1_info *info, + unsigned int *avail) +{ + struct vfio_info_cap_header *hdr; + struct vfio_iommu_type1_info_dma_avail *cap; + + /* If the capability cannot be found, assume no DMA limiting */ + hdr = vfio_get_iommu_type1_info_cap(info, + VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL); + if (hdr == NULL) { + return false; + } + + if (avail != NULL) { + cap = (void *) hdr; + *avail = cap->avail; + } + + return true; +} + static int vfio_setup_region_sparse_mmaps(VFIORegion *region, struct vfio_region_info *info) { diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index fd564209ac7..aa6cbe4a998 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -191,6 +191,8 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type, bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type); struct vfio_info_cap_header * vfio_get_region_info_cap(struct vfio_region_info *info, uint16_t id); +bool vfio_get_info_dma_avail(struct vfio_iommu_type1_info *info, + unsigned int *avail); #endif extern const MemoryListener vfio_prereg_listener; -- 2.27.0