In case we detect the address space is translated by a virtual IOMMU which requires HW nested paging to integrate with VFIO, let's set up the container with the VFIO_TYPE1_NESTING_IOMMU iommu_type.
Signed-off-by: Eric Auger <eric.au...@redhat.com> --- v4 -> v5: - fail immediatly if nested is wanted but not supported v2 -> v3: - add "nested only is selected if requested by @force_nested" comment in this patch --- hw/vfio/common.c | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 0b3593b3c0..ac417b5dbd 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1155,27 +1155,38 @@ static void vfio_put_address_space(VFIOAddressSpace *space) * vfio_get_iommu_type - selects the richest iommu_type (v2 first) */ static int vfio_get_iommu_type(VFIOContainer *container, + bool want_nested, Error **errp) { - int iommu_types[] = { VFIO_TYPE1v2_IOMMU, VFIO_TYPE1_IOMMU, + int iommu_types[] = { VFIO_TYPE1_NESTING_IOMMU, + VFIO_TYPE1v2_IOMMU, VFIO_TYPE1_IOMMU, VFIO_SPAPR_TCE_v2_IOMMU, VFIO_SPAPR_TCE_IOMMU }; - int i; + int i, ret = -EINVAL; for (i = 0; i < ARRAY_SIZE(iommu_types); i++) { if (ioctl(container->fd, VFIO_CHECK_EXTENSION, iommu_types[i])) { - return iommu_types[i]; + if (iommu_types[i] == VFIO_TYPE1_NESTING_IOMMU && !want_nested) { + continue; + } + ret = iommu_types[i]; + break; } } - error_setg(errp, "No available IOMMU models"); - return -EINVAL; + if (ret < 0) { + error_setg(errp, "No available IOMMU models"); + } else if (want_nested && ret != VFIO_TYPE1_NESTING_IOMMU) { + error_setg(errp, "Nested mode requested but not supported"); + ret = -EINVAL; + } + return ret; } static int vfio_init_container(VFIOContainer *container, int group_fd, - Error **errp) + bool want_nested, Error **errp) { int iommu_type, ret; - iommu_type = vfio_get_iommu_type(container, errp); + iommu_type = vfio_get_iommu_type(container, want_nested, errp); if (iommu_type < 0) { return iommu_type; } @@ -1211,6 +1222,14 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, VFIOContainer *container; int ret, fd; VFIOAddressSpace *space; + IOMMUMemoryRegion *iommu_mr; + bool nested = false; + + if (as != &address_space_memory && memory_region_is_iommu(as->root)) { + iommu_mr = IOMMU_MEMORY_REGION(as->root); + memory_region_iommu_get_attr(iommu_mr, IOMMU_ATTR_VFIO_NESTED, + (void *)&nested); + } space = vfio_get_address_space(as); @@ -1272,12 +1291,13 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, QLIST_INIT(&container->giommu_list); QLIST_INIT(&container->hostwin_list); - ret = vfio_init_container(container, group->fd, errp); + ret = vfio_init_container(container, group->fd, nested, errp); if (ret) { goto free_container_exit; } switch (container->iommu_type) { + case VFIO_TYPE1_NESTING_IOMMU: case VFIO_TYPE1v2_IOMMU: case VFIO_TYPE1_IOMMU: { -- 2.20.1