From: Cindy Lu lulu@redhat.com
commit c82729e06644f4e087f5ff0f91b8fb15e03b8890 upstream.
While using the vdpa device with vIOMMU enabled in the guest VM, when the vdpa device bind to vfio-pci and run testpmd then system will fail to unmap. The test process is Load guest VM --> attach to virtio driver--> bind to vfio-pci driver So the mapping process is 1)batched mode map to normal MR 2)batched mode unmapped the normal MR 3)unmapped all the memory 4)mapped to iommu MR
This error happened in step 3). The iotlb was freed in step 2) and the function vhost_vdpa_process_iotlb_msg will return fail Which causes failure.
To fix this, we will not remove the AS while the iotlb->nmaps is 0. This will free in the vhost_vdpa_clean
Cc: stable@vger.kernel.org Fixes: aaca8373c4b1 ("vhost-vdpa: support ASID based IOTLB API") Signed-off-by: Cindy Lu lulu@redhat.com Message-Id: 20230420151734.860168-1-lulu@redhat.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/vhost/vdpa.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)
--- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -851,11 +851,7 @@ static void vhost_vdpa_unmap(struct vhos if (!v->in_batch) ops->set_map(vdpa, asid, iotlb); } - /* If we are in the middle of batch processing, delay the free - * of AS until BATCH_END. - */ - if (!v->in_batch && !iotlb->nmaps) - vhost_vdpa_remove_as(v, asid); + }
static int vhost_vdpa_va_map(struct vhost_vdpa *v, @@ -1112,8 +1108,6 @@ static int vhost_vdpa_process_iotlb_msg( if (v->in_batch && ops->set_map) ops->set_map(vdpa, asid, iotlb); v->in_batch = false; - if (!iotlb->nmaps) - vhost_vdpa_remove_as(v, asid); break; default: r = -EINVAL;