From: Willem de Bruijn <will...@google.com>
Allow the tun device to intercept zerocopy completions to increment
its counters.
Pass an array of two struct ubuf_info to the device. The first is
initialized as usual and used to notify vhost_net. The second is
granted to the tun device for its callback.
Use the existing per-device ubuf_info pool, but take out two
elements at a time, so double the size.
Signed-off-by: Willem de Bruijn <will...@google.com>
---
drivers/vhost/net.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 58585ec8699e..22988a7df656 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -47,6 +47,7 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
/* MAX number of TX used buffers for outstanding zerocopy */
#define VHOST_MAX_PEND 128
#define VHOST_GOODCOPY_LEN 256
+#define UBUFLEN 2 /* Number of consecutive ubuf_info passed to tun */
/*
* For transmit, used buffer len is unused; we override it to track buffer
@@ -254,7 +255,7 @@ static int vhost_net_set_ubuf_info(struct vhost_net *n)
if (!zcopy)
continue;
n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) *
- UIO_MAXIOV, GFP_KERNEL);
+ UIO_MAXIOV * UBUFLEN, GFP_KERNEL);
if (!n->vqs[i].ubuf_info)
goto err;
}
@@ -526,7 +527,7 @@ static void handle_tx(struct vhost_net *net)
/* use msg_control to pass vhost zerocopy ubuf info to skb */
if (zcopy_used) {
struct ubuf_info *ubuf;
- ubuf = nvq->ubuf_info + nvq->upend_idx;
+ ubuf = nvq->ubuf_info + (nvq->upend_idx * UBUFLEN);
vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
@@ -535,7 +536,7 @@ static void handle_tx(struct vhost_net *net)
ubuf->desc = nvq->upend_idx;
refcount_set(&ubuf->refcnt, 1);
msg.msg_control = ubuf;
- msg.msg_controllen = sizeof(ubuf);
+ msg.msg_controllen = sizeof(*ubuf) * UBUFLEN;
ubufs = nvq->ubufs;
atomic_inc(&ubufs->refcount);
nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
--
2.14.2.920.gcf0c67979c-goog
