VFIO exposes host IOMMU dual-stage DMA translation programming capability to userspace by VFIO_TYPE1_NESTING_IOMMU type. However, userspace needs more info on the nesting type. e.g. the supported stage 1 format and PASID alloc/free request availability. This patch gets the iommu nesting cap info from kernel by using IOCTL VFIO_IOMMU_GET_INFO. And checks the HOST_IOMMU_PASID_REQUEST bit in the nesting capabilities. This patch referred some code from Shameer Kolothum. https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg03759.html Cc: Kevin Tian <kevin.tian@xxxxxxxxx> Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> Cc: Peter Xu <peterx@xxxxxxxxxx> Cc: Eric Auger <eric.auger@xxxxxxxxxx> Cc: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx> Cc: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx> --- hw/vfio/common.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 91 insertions(+), 5 deletions(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index e4f5f10..e0f2828 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1223,6 +1223,84 @@ static int vfio_host_icx_pasid_free(HostIOMMUContext *host_icx, return 0; } +/** + * Get iommu info from host. Caller of this funcion should free + * the memory pointed by the returned pointer stored in @info + * after a successful calling when finished its usage. + */ +static int vfio_get_iommu_info(VFIOContainer *container, + struct vfio_iommu_type1_info **info) +{ + + size_t argsz = sizeof(struct vfio_iommu_type1_info); + + *info = g_malloc0(argsz); + +retry: + (*info)->argsz = argsz; + + if (ioctl(container->fd, VFIO_IOMMU_GET_INFO, *info)) { + g_free(*info); + *info = NULL; + return -errno; + } + + if (((*info)->argsz > argsz)) { + argsz = (*info)->argsz; + *info = g_realloc(*info, argsz); + goto retry; + } + + return 0; +} + +static struct vfio_info_cap_header * +vfio_get_iommu_info_cap(struct vfio_iommu_type1_info *info, uint16_t id) +{ + struct vfio_info_cap_header *hdr; + void *ptr = info; + + if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) { + return NULL; + } + + for (hdr = ptr + info->cap_offset; hdr != ptr; hdr = ptr + hdr->next) { + if (hdr->id == id) { + return hdr; + } + } + + return NULL; +} + +static int vfio_get_nesting_iommu_cap(VFIOContainer *container, + struct vfio_iommu_type1_info_cap_nesting *cap_nesting) +{ + struct vfio_iommu_type1_info *info; + struct vfio_info_cap_header *hdr; + struct vfio_iommu_type1_info_cap_nesting *cap; + int ret; + + ret = vfio_get_iommu_info(container, &info); + if (ret) { + return ret; + } + + hdr = vfio_get_iommu_info_cap(info, + VFIO_IOMMU_TYPE1_INFO_CAP_NESTING); + if (!hdr) { + g_free(info); + return -errno; + } + + cap = container_of(hdr, + struct vfio_iommu_type1_info_cap_nesting, header); + *cap_nesting = *cap; + + g_free(info); + return 0; +} + static int vfio_init_container(VFIOContainer *container, int group_fd, Error **errp) { @@ -1256,11 +1334,19 @@ static int vfio_init_container(VFIOContainer *container, int group_fd, } if (iommu_type == VFIO_TYPE1_NESTING_IOMMU) { - /* - * TODO: config flags per host IOMMU nesting capability - * e.g. check if VFIO_TYPE1_NESTING_IOMMU supports PASID - * alloc/free - */ + struct vfio_iommu_type1_info_cap_nesting nesting = { + .nesting_capabilities = 0x0, + .stage1_formats = 0, }; + + ret = vfio_get_nesting_iommu_cap(container, &nesting); + if (ret) { + error_setg_errno(errp, -ret, + "Failed to get nesting iommu cap"); + return ret; + } + + flags |= (nesting.nesting_capabilities & VFIO_IOMMU_PASID_REQS) ? + HOST_IOMMU_PASID_REQUEST : 0; host_iommu_ctx_init(&container->host_icx, sizeof(container->host_icx), TYPE_VFIO_HOST_IOMMU_CONTEXT, -- 2.7.4
