On Thu, Jan 09, 2025 at 06:38:10PM +0900, Akihiko Odaki wrote:
On 2025/01/09 16:40, Michael S. Tsirkin wrote:
On Thu, Jan 09, 2025 at 02:32:25AM -0500, Michael S. Tsirkin wrote:
On Thu, Jan 09, 2025 at 03:58:45PM +0900, Akihiko Odaki wrote:
The specification says the device MUST set num_buffers to 1 if VIRTIO_NET_F_MRG_RXBUF has not been negotiated.
Signed-off-by: Akihiko Odaki akihiko.odaki@daynix.com
How do we know this is v1 and not v0? Confused.
Ah I got it, you assume userspace will over-write it if VIRTIO_NET_F_MRG_RXBUF is set. If we are leaving this up to userspace, why not let it do it always?
tun may be used with vhost_net, which does not set the field.
I'd fix that in vhost net.
drivers/net/tap.c | 2 +- drivers/net/tun.c | 6 ++++-- drivers/net/tun_vnet.c | 14 +++++++++----- drivers/net/tun_vnet.h | 4 ++-- 4 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 60804855510b..fe9554ee5b8b 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -713,7 +713,7 @@ static ssize_t tap_put_user(struct tap_queue *q, int total; if (q->flags & IFF_VNET_HDR) {
struct virtio_net_hdr vnet_hdr;
struct virtio_net_hdr_v1 vnet_hdr;diff --git a/drivers/net/tun.c b/drivers/net/tun.c index dbf0dee92e93..f211d0580887 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1991,7 +1991,9 @@ static ssize_t tun_put_user_xdp(struct tun_struct *tun, size_t total; if (tun->flags & IFF_VNET_HDR) {
struct virtio_net_hdr gso = { 0 };
struct virtio_net_hdr_v1 gso = {.num_buffers = __virtio16_to_cpu(true, 1)};@@ -2044,7 +2046,7 @@ static ssize_t tun_put_user(struct tun_struct *tun, } if (vnet_hdr_sz) {
struct virtio_net_hdr gso;
struct virtio_net_hdr_v1 gso;diff --git a/drivers/net/tun_vnet.c b/drivers/net/tun_vnet.c index ffb2186facd3..a7a7989fae56 100644 --- a/drivers/net/tun_vnet.c +++ b/drivers/net/tun_vnet.c @@ -130,15 +130,17 @@ int tun_vnet_hdr_get(int sz, unsigned int flags, struct iov_iter *from, EXPORT_SYMBOL_GPL(tun_vnet_hdr_get); int tun_vnet_hdr_put(int sz, struct iov_iter *iter,
const struct virtio_net_hdr *hdr)
const struct virtio_net_hdr_v1 *hdr)- int content_sz = MIN(sizeof(*hdr), sz);
- if (iov_iter_count(iter) < sz) return -EINVAL;
- if (copy_to_iter(hdr, sizeof(*hdr), iter) != sizeof(*hdr))
- if (copy_to_iter(hdr, content_sz, iter) != content_sz) return -EFAULT;
- if (iov_iter_zero(sz - sizeof(*hdr), iter) != sz - sizeof(*hdr))
- if (iov_iter_zero(sz - content_sz, iter) != sz - content_sz) return -EFAULT; return 0;
@@ -154,11 +156,11 @@ EXPORT_SYMBOL_GPL(tun_vnet_hdr_to_skb); int tun_vnet_hdr_from_skb(unsigned int flags, const struct net_device *dev, const struct sk_buff *skb,
struct virtio_net_hdr *hdr)
struct virtio_net_hdr_v1 *hdr)
- if (virtio_net_hdr_from_skb(skb, hdr,
- if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)hdr, tun_vnet_is_little_endian(flags), true, vlan_hlen)) { struct skb_shared_info *sinfo = skb_shinfo(skb);
@@ -176,6 +178,8 @@ int tun_vnet_hdr_from_skb(unsigned int flags, const struct net_device *dev, return -EINVAL; }
- hdr->num_buffers = 1;
- return 0; } EXPORT_SYMBOL_GPL(tun_vnet_hdr_from_skb);
diff --git a/drivers/net/tun_vnet.h b/drivers/net/tun_vnet.h index 2dfdbe92bb24..d8fd94094227 100644 --- a/drivers/net/tun_vnet.h +++ b/drivers/net/tun_vnet.h @@ -12,13 +12,13 @@ int tun_vnet_hdr_get(int sz, unsigned int flags, struct iov_iter *from, struct virtio_net_hdr *hdr); int tun_vnet_hdr_put(int sz, struct iov_iter *iter,
const struct virtio_net_hdr *hdr);
const struct virtio_net_hdr_v1 *hdr);
struct virtio_net_hdr *hdr);
struct virtio_net_hdr_v1 *hdr);-- 2.47.1