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.
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 2bd219cf1d..1babb6bb99 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1934,6 +1934,7 @@ 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); @@ -1965,7 +1966,10 @@ 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
