Re: [RFC PATCH 2/2] RDMA/efa: Add support for dmabuf memory regions

On Thu, Oct 07, 2021 at 01:43:00PM +0300, Gal Pressman wrote:

@@ -1491,26 +1493,29 @@ static int efa_create_pbl(struct efa_dev *dev, return 0; }

-struct ib_mr *efa_reg_mr(struct ib_pd *ibpd, u64 start, u64 length,

• 	 u64 virt_addr, int access_flags,
  

• 	 struct ib_udata *udata)
  

+static void efa_dmabuf_invalidate_cb(struct dma_buf_attachment *attach) +{

• WARN_ON_ONCE(1,

•      "Invalidate callback should not be called when memory is pinned\n");
  

+}

+static struct dma_buf_attach_ops efa_dmabuf_attach_ops = {

• .allow_peer2peer = true,
• .move_notify = efa_dmabuf_invalidate_cb,

+};

Shouldn't move_notify really just be left as NULL? I mean fixing whatever is preventing that?

+struct ib_mr *efa_reg_user_mr_dmabuf(struct ib_pd *ibpd, u64 start,

• 		     u64 length, u64 virt_addr,
  

• 		     int fd, int access_flags,
  

• 		     struct ib_udata *udata)
  

+{

• struct efa_dev *dev = to_edev(ibpd->device);
• struct ib_umem_dmabuf *umem_dmabuf;
• struct efa_mr *mr;
• int err;
• mr = efa_alloc_mr(ibpd, access_flags, udata);
• if (IS_ERR(mr)) {

• err = PTR_ERR(mr);
  

• goto err_out;
  

• }
• umem_dmabuf = ib_umem_dmabuf_get(ibpd->device, start, length, fd,

• 			 access_flags, &efa_dmabuf_attach_ops);
  

• if (IS_ERR(umem_dmabuf)) {

• ibdev_dbg(&dev->ibdev, "Failed to get dmabuf[%d]\n", err);
  

• err = PTR_ERR(umem_dmabuf);
  

• goto err_free;
  

• }
• dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
• err = dma_buf_pin(umem_dmabuf->attach);
• if (err) {

• ibdev_dbg(&dev->ibdev, "Failed to pin dmabuf memory\n");
  

• goto err_release;
  

• }
• err = ib_umem_dmabuf_map_pages(umem_dmabuf);
• if (err) {

• ibdev_dbg(&dev->ibdev, "Failed to map dmabuf pages\n");
  

• goto err_unpin;
  

• }
• dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);

If it is really this simple the core code should have this logic, 'ib_umem_dmabuf_get_pinned()' or something

Jason