Commit bda324fd037a ("vdpasim: control virtqueue support") added two new fields (nas, ngroups) to vdpasim_dev_attr, but we forgot to initialize them for vdpa_sim_blk. When creating a new vdpa_sim_blk device this causes the kernel to panic in this way: $ vdpa dev add mgmtdev vdpasim_blk name blk0 BUG: kernel NULL pointer dereference, address: 0000000000000030 ... RIP: 0010:vhost_iotlb_add_range_ctx+0x41/0x220 [vhost_iotlb] ... Call Trace: <TASK> vhost_iotlb_add_range+0x11/0x800 [vhost_iotlb] vdpasim_map_range+0x91/0xd0 [vdpa_sim] vdpasim_alloc_coherent+0x56/0x90 [vdpa_sim] ... This happens because vdpasim->iommu[0] is not initialized when dev_attr.nas is 0. Let's fix this issue by initializing both (nas, ngroups) to 1 for vdpa_sim_blk. Fixes: bda324fd037a ("vdpasim: control virtqueue support") Cc: gautam.dawar@xxxxxxxxxx Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> --- drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c index 42d401d43911..03a28def8eee 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c @@ -34,7 +34,11 @@ #define VDPASIM_BLK_CAPACITY 0x40000 #define VDPASIM_BLK_SIZE_MAX 0x1000 #define VDPASIM_BLK_SEG_MAX 32 + +/* 1 virtqueue, 1 address space, 1 virtqueue group */ #define VDPASIM_BLK_VQ_NUM 1 +#define VDPASIM_BLK_AS_NUM 1 +#define VDPASIM_BLK_GROUP_NUM 1 static char vdpasim_blk_id[VIRTIO_BLK_ID_BYTES] = "vdpa_blk_sim"; @@ -260,6 +264,8 @@ static int vdpasim_blk_dev_add(struct vdpa_mgmt_dev *mdev, const char *name, dev_attr.id = VIRTIO_ID_BLOCK; dev_attr.supported_features = VDPASIM_BLK_FEATURES; dev_attr.nvqs = VDPASIM_BLK_VQ_NUM; + dev_attr.ngroups = VDPASIM_BLK_GROUP_NUM; + dev_attr.nas = VDPASIM_BLK_AS_NUM; dev_attr.config_size = sizeof(struct virtio_blk_config); dev_attr.get_config = vdpasim_blk_get_config; dev_attr.work_fn = vdpasim_blk_work; -- 2.36.1 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization