Make sure list of mapping/attaching activities on impoter VM is not empty before doing unmapping/detaching shadow DMA BUF for indirect synchronization.
Signed-off-by: Dongwon Kim dongwon.kim@intel.com --- .../xen/hyper_dmabuf/hyper_dmabuf_remote_sync.c | 68 +++++++++++++++++----- 1 file changed, 53 insertions(+), 15 deletions(-)
diff --git a/drivers/xen/hyper_dmabuf/hyper_dmabuf_remote_sync.c b/drivers/xen/hyper_dmabuf/hyper_dmabuf_remote_sync.c index 6ba932f..fa2fa11 100644 --- a/drivers/xen/hyper_dmabuf/hyper_dmabuf_remote_sync.c +++ b/drivers/xen/hyper_dmabuf/hyper_dmabuf_remote_sync.c @@ -11,6 +11,21 @@
extern struct hyper_dmabuf_private hyper_dmabuf_private;
+/* Whenever importer does dma operations from remote domain, + * a notification is sent to the exporter so that exporter + * issues equivalent dma operation on the original dma buf + * for indirect synchronization via shadow operations. + * + * All ptrs and references (e.g struct sg_table*, + * struct dma_buf_attachment) created via these operations on + * exporter's side are kept in stack (implemented as circular + * linked-lists) separately so that those can be re-referenced + * later when unmapping operations are invoked to free those. + * + * The very first element on the bottom of each stack holds + * are what is created when initial exporting is issued so it + * should not be modified or released by this fuction. + */ int hyper_dmabuf_remote_sync(int id, int ops) { struct hyper_dmabuf_sgt_info *sgt_info; @@ -33,7 +48,7 @@ int hyper_dmabuf_remote_sync(int id, int ops) attachl = kcalloc(1, sizeof(*attachl), GFP_KERNEL);
attachl->attach = dma_buf_attach(sgt_info->dma_buf, - hyper_dmabuf_private.device); + hyper_dmabuf_private.device);
if (!attachl->attach) { kfree(attachl); @@ -45,22 +60,31 @@ int hyper_dmabuf_remote_sync(int id, int ops) break;
case HYPER_DMABUF_OPS_DETACH: - attachl = list_first_entry(&sgt_info->active_attached->list, - struct attachment_list, list); - - if (!attachl) { + if (list_empty(&sgt_info->active_attached->list)) { printk("dmabuf remote sync::error while processing HYPER_DMABUF_OPS_DETACH\n"); + printk("no more dmabuf attachment left to be detached\n"); return -EINVAL; } + + attachl = list_first_entry(&sgt_info->active_attached->list, + struct attachment_list, list); + dma_buf_detach(sgt_info->dma_buf, attachl->attach); list_del(&attachl->list); kfree(attachl); break;
case HYPER_DMABUF_OPS_MAP: - sgtl = kcalloc(1, sizeof(*sgtl), GFP_KERNEL); + if (list_empty(&sgt_info->active_attached->list)) { + printk("dmabuf remote sync::error while processing HYPER_DMABUF_OPS_MAP\n"); + printk("no more dmabuf attachment left to be detached\n"); + return -EINVAL; + } + attachl = list_first_entry(&sgt_info->active_attached->list, - struct attachment_list, list); + struct attachment_list, list); + + sgtl = kcalloc(1, sizeof(*sgtl), GFP_KERNEL); sgtl->sgt = dma_buf_map_attachment(attachl->attach, DMA_BIDIRECTIONAL); if (!sgtl->sgt) { kfree(sgtl); @@ -71,17 +95,20 @@ int hyper_dmabuf_remote_sync(int id, int ops) break;
case HYPER_DMABUF_OPS_UNMAP: - attachl = list_first_entry(&sgt_info->active_attached->list, - struct attachment_list, list); - sgtl = list_first_entry(&sgt_info->active_sgts->list, - struct sgt_list, list); - if (!attachl || !sgtl) { + if (list_empty(&sgt_info->active_sgts->list) || + list_empty(&sgt_info->active_attached->list)) { printk("dmabuf remote sync::error while processing HYPER_DMABUF_OPS_UNMAP\n"); + printk("no more SGT or attachment left to be freed\n"); return -EINVAL; }
+ attachl = list_first_entry(&sgt_info->active_attached->list, + struct attachment_list, list); + sgtl = list_first_entry(&sgt_info->active_sgts->list, + struct sgt_list, list); + dma_buf_unmap_attachment(attachl->attach, sgtl->sgt, - DMA_BIDIRECTIONAL); + DMA_BIDIRECTIONAL); list_del(&sgtl->list); kfree(sgtl); break; @@ -129,9 +156,15 @@ int hyper_dmabuf_remote_sync(int id, int ops)
case HYPER_DMABUF_OPS_KUNMAP_ATOMIC: case HYPER_DMABUF_OPS_KUNMAP: + if (list_empty(&sgt_info->va_kmapped->list)) { + printk("dmabuf remote sync::error while processing HYPER_DMABUF_OPS_KUNMAP(_ATOMIC)\n"); + printk("no more dmabuf VA to be freed\n"); + return -EINVAL; + } + va_kmapl = list_first_entry(&sgt_info->va_kmapped->list, - struct kmap_vaddr_list, list); - if (!va_kmapl || va_kmapl->vaddr == NULL) { + struct kmap_vaddr_list, list); + if (va_kmapl->vaddr == NULL) { printk("dmabuf remote sync::error while processing HYPER_DMABUF_OPS_KUNMAP(_ATOMIC)\n"); return -EINVAL; } @@ -167,6 +200,11 @@ int hyper_dmabuf_remote_sync(int id, int ops) break;
case HYPER_DMABUF_OPS_VUNMAP: + if (list_empty(&sgt_info->va_vmapped->list)) { + printk("dmabuf remote sync::error while processing HYPER_DMABUF_OPS_VUNMAP\n"); + printk("no more dmabuf VA to be freed\n"); + return -EINVAL; + } va_vmapl = list_first_entry(&sgt_info->va_vmapped->list, struct vmap_vaddr_list, list); if (!va_vmapl || va_vmapl->vaddr == NULL) {