diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/hw/virtio/vhost-vdpa.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h index 221840987e..449bf5c840 100644 --- a/include/hw/virtio/vhost-vdpa.h +++ b/include/hw/virtio/vhost-vdpa.h @@ -43,7 +43,21 @@ typedef struct vhost_vdpa_shared { struct vhost_vdpa_iova_range iova_range; QLIST_HEAD(, vdpa_iommu) iommu_list; - /* IOVA mapping used by the Shadow Virtqueue */ + /* + * IOVA mapping used by the Shadow Virtqueue + * + * It is shared among all ASID for simplicity, whether CVQ shares ASID with + * guest or not: + * - Memory listener need access to guest's memory addresses allocated in + * the IOVA tree. + * - There should be plenty of IOVA address space for both ASID not to + * worry about collisions between them. Guest's translations are still + * validated with virtio virtqueue_pop so there is no risk for the guest + * to access memory that it shouldn't. + * + * To allocate a iova tree per ASID is doable but it complicates the code + * and it is not worth it for the moment. + */ VhostIOVATree *iova_tree; /* Copy of backend features */ |