Let's query the maximum number of possible DMA mappings by querying the available mappings when creating the container (before any mappings are created). We'll use this informaton soon to perform some sanity checks and warn the user.
Reviewed-by: Alex Williamson <[email protected]> Acked-by: Alex Williamson <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: "Michael S. Tsirkin" <[email protected]> Cc: Alex Williamson <[email protected]> Cc: Dr. David Alan Gilbert <[email protected]> Cc: Igor Mammedov <[email protected]> Cc: Pankaj Gupta <[email protected]> Cc: Peter Xu <[email protected]> Cc: Auger Eric <[email protected]> Cc: Wei Yang <[email protected]> Cc: teawater <[email protected]> Cc: Marek Kedzierski <[email protected]> Signed-off-by: David Hildenbrand <[email protected]> --- hw/vfio/common.c | 4 ++++ include/hw/vfio/vfio-common.h | 1 + 2 files changed, 5 insertions(+) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index f68370de6c..78be813a53 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1937,6 +1937,7 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, container->fd = fd; container->error = NULL; container->dirty_pages_supported = false; + container->dma_max_mappings = 0; QLIST_INIT(&container->giommu_list); QLIST_INIT(&container->hostwin_list); QLIST_INIT(&container->vrdl_list); @@ -1968,7 +1969,10 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, vfio_host_win_add(container, 0, (hwaddr)-1, info->iova_pgsizes); container->pgsizes = info->iova_pgsizes; + /* The default in the kernel ("dma_entry_limit") is 65535. */ + container->dma_max_mappings = 65535; if (!ret) { + vfio_get_info_dma_avail(info, &container->dma_max_mappings); vfio_get_iommu_info_migration(container, info); } g_free(info); diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index af6f8d1b22..4b28c6e8ac 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -88,6 +88,7 @@ typedef struct VFIOContainer { uint64_t dirty_pgsizes; uint64_t max_dirty_bitmap_size; unsigned long pgsizes; + unsigned int dma_max_mappings; QLIST_HEAD(, VFIOGuestIOMMU) giommu_list; QLIST_HEAD(, VFIOHostDMAWindow) hostwin_list; QLIST_HEAD(, VFIOGroup) group_list; -- 2.29.2
