diff mbox series

[net-next,v3,1/8] xsk: XDP_SETUP_XSK_POOL support option check_dma

Message ID 20210331071139.15473-2-xuanzhuo@linux.alibaba.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series virtio-net support xdp socket zero copy xmit | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 16 of 16 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 6676 this patch: 6676
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 21 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 6889 this patch: 6889
netdev/header_inline success Link

Commit Message

Xuan Zhuo March 31, 2021, 7:11 a.m. UTC 
The check_dma option is added to the bpf command. Because virtio-net
does not complete the dma initialization in advance. Instead, vring does
the dma operation every time data is sent.

Of course, in theory, it would be better to complete the dma
initialization in advance. But the modification vring may be more
troublesome, so here is an option to notify xsk dma whether the
initialization is complete. In this way, xsk will not report an error
because dma has not been initialized.

Of course, I still hope that virtio-net can support the completion of
dma operations in advance.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
---
 include/linux/netdevice.h | 1 +
 net/xdp/xsk_buff_pool.c   | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f57b70fc251f..47666b5d2dff 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -979,6 +979,7 @@  struct netdev_bpf {
 		struct {
 			struct xsk_buff_pool *pool;
 			u16 queue_id;
+			bool check_dma;
 		} xsk;
 	};
 };
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 8de01aaac4a0..4d3aed73ee3e 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -166,12 +166,13 @@  int xp_assign_dev(struct xsk_buff_pool *pool,
 	bpf.command = XDP_SETUP_XSK_POOL;
 	bpf.xsk.pool = pool;
 	bpf.xsk.queue_id = queue_id;
+	bpf.xsk.check_dma = true;
 
 	err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
 	if (err)
 		goto err_unreg_pool;
 
-	if (!pool->dma_pages) {
+	if (bpf.xsk.check_dma && !pool->dma_pages) {
 		WARN(1, "Driver did not DMA map zero-copy buffers");
 		err = -EINVAL;
 		goto err_unreg_xsk;