Hi Yi,
On 3/30/20 6:24 AM, Liu Yi L wrote:
> In this patch, QEMU firstly gets iommu info from kernel to check the
> supported capabilities by a VFIO_IOMMU_TYPE1_NESTING iommu. And inits
> HostIOMMUContet instance.
>
> 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: Liu Yi L <yi.l.liu@xxxxxxxxx>
> ---
> hw/vfio/common.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 99 insertions(+)
>
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 5f3534d..44b142c 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -1226,10 +1226,89 @@ static int vfio_host_iommu_ctx_pasid_free(HostIOMMUContext *iommu_ctx,
> 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)
> {
> int iommu_type, ret;
> + uint64_t flags = 0;
>
> iommu_type = vfio_get_iommu_type(container, errp);
> if (iommu_type < 0) {
> @@ -1257,6 +1336,26 @@ static int vfio_init_container(VFIOContainer *container, int group_fd,
> return -errno;
> }
>
> + if (iommu_type == VFIO_TYPE1_NESTING_IOMMU) {
> + 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;
I still don't get why you can't transform your iommu_ctx into a pointer
and do
container->iommu_ctx = g_new0(HostIOMMUContext, 1);
then
host_iommu_ctx_init(container->iommu_ctx, flags);
looks something similar to (hw/vfio/common.c). You may not even need to
use a derived VFIOHostIOMMUContext object (As only VFIO does use that
object)? Only the ops do change, no new field?
region->mem = g_new0(MemoryRegion, 1);
memory_region_init_io(region->mem, obj, &vfio_region_ops,
region, name, region->size);
Thanks
Eric
> + host_iommu_ctx_init(&container->iommu_ctx,
> + sizeof(container->iommu_ctx),
> + TYPE_VFIO_HOST_IOMMU_CONTEXT,
> + flags);
> + }
> +
> container->iommu_type = iommu_type;
> return 0;
> }
>
