similar to: [PATCHv2 net] vhost: fix total length when packets are too short

When mergeable buffers are disabled, and the incoming packet is too large for the rx buffer, get_rx_bufs returns success. This was intentional in order for make recvmsg truncate the packet and then handle_rx would detect err != sock_len and drop it. Unfortunately we pass the original sock_len to recvmsg - which means we use parts of iov not fully validated. Fix this up by detecting this overrun

When mergeable buffers are disabled, and the incoming packet is too large for the rx buffer, get_rx_bufs returns success. This was intentional in order for make recvmsg truncate the packet and then handle_rx would detect err != sock_len and drop it. Unfortunately we pass the original sock_len to recvmsg - which means we use parts of iov not fully validated. Fix this up by detecting this overrun

On 2017?11?29? 23:31, Michael S. Tsirkin wrote: > On Wed, Nov 29, 2017 at 09:23:24AM -0500,wexu at redhat.com wrote: >> From: Wei Xu<wexu at redhat.com> >> >> Matthew found a roughly 40% tcp throughput regression with commit >> c67df11f(vhost_net: try batch dequing from skb array) as discussed >> in the following thread: >>

On 2017?11?29? 23:31, Michael S. Tsirkin wrote: > On Wed, Nov 29, 2017 at 09:23:24AM -0500,wexu at redhat.com wrote: >> From: Wei Xu<wexu at redhat.com> >> >> Matthew found a roughly 40% tcp throughput regression with commit >> c67df11f(vhost_net: try batch dequing from skb array) as discussed >> in the following thread: >>

From: Wei Xu <wexu at redhat.com> Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev at vger.kernel.org/msg187936.html Eventually we figured out that it was a skb leak in handle_rx() when sending packets to the VM. This usually happens when a guest

From: Wei Xu <wexu at redhat.com> Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev at vger.kernel.org/msg187936.html Eventually we figured out that it was a skb leak in handle_rx() when sending packets to the VM. This usually happens when a guest

From: Wei Xu <wexu at redhat.com> Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev at vger.kernel.org/msg187936.html Eventually we figured out that it was a skb leak in handle_rx() when sending packets to the VM. This usually happens when a guest

Hi Jason, I love your patch! Yet something to improve: [auto build test ERROR on net-next/master] url: https://github.com/0day-ci/linux/commits/Jason-Wang/Packed-virtqueue-for-vhost/20180703-154751 config: x86_64-randconfig-s0-07032254 (attached as .config) compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026 reproduce: # save the attached .config to linux build tree make

On Fri, Dec 01, 2017 at 03:11:05PM +0800, Jason Wang wrote: > > > On 2017?12?01? 13:54, wexu at redhat.com wrote: > > From: Wei Xu <wexu at redhat.com> > > > > Matthew found a roughly 40% tcp throughput regression with commit > > c67df11f(vhost_net: try batch dequing from skb array) as discussed > > in the following thread: > >

On Fri, Dec 01, 2017 at 03:11:05PM +0800, Jason Wang wrote: > > > On 2017?12?01? 13:54, wexu at redhat.com wrote: > > From: Wei Xu <wexu at redhat.com> > > > > Matthew found a roughly 40% tcp throughput regression with commit > > c67df11f(vhost_net: try batch dequing from skb array) as discussed > > in the following thread: > >

When the rx buffer is too small for a packet, we will discard the vq descriptor and retry it for the next packet: while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, &busyloop_intr))) { ... /* On overrun, truncate and discard */ if (unlikely(headcount > UIO_MAXIOV)) { iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1); err = sock->ops->recvmsg(sock,

When the rx buffer is too small for a packet, we will discard the vq descriptor and retry it for the next packet: while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, &busyloop_intr))) { ... /* On overrun, truncate and discard */ if (unlikely(headcount > UIO_MAXIOV)) { iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1); err = sock->ops->recvmsg(sock,

On 2020/6/2 ??9:06, Michael S. Tsirkin wrote: > Convert vhost net to use the new format-agnostic API. > In particular, don't poke at vq internals such as the > heads array. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> > --- > drivers/vhost/net.c | 153 +++++++++++++++++++++++--------------------- > 1 file changed, 81 insertions(+), 72 deletions(-)

On 2019/4/26 ??1:52, Michael S. Tsirkin wrote: > On Thu, Apr 25, 2019 at 03:33:19AM -0400, Jason Wang wrote: >> When the rx buffer is too small for a packet, we will discard the vq >> descriptor and retry it for the next packet: >> >> while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, >> &busyloop_intr))) { >> ... >> /* On

On 2019/4/26 ??1:52, Michael S. Tsirkin wrote: > On Thu, Apr 25, 2019 at 03:33:19AM -0400, Jason Wang wrote: >> When the rx buffer is too small for a packet, we will discard the vq >> descriptor and retry it for the next packet: >> >> while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk, >> &busyloop_intr))) { >> ... >> /* On

After commit e2b3b35eb989 ("vhost_net: batch used ring update in rx"), we tend to batch updating used heads. But it doesn't flush batched heads before trying to do busy polling, this will cause vhost to wait for guest TX which waits for the used RX. Fixing by flush batched heads before busy loop. 1 byte TCP_RR performance recovers from 13107.83 to 50402.65. Fixes: e2b3b35eb989

On 2017?11?29? 22:23, wexu at redhat.com wrote: > From: Wei Xu <wexu at redhat.com> > > Matthew found a roughly 40% tcp throughput regression with commit > c67df11f(vhost_net: try batch dequing from skb array) as discussed > in the following thread: > https://www.mail-archive.com/netdev at vger.kernel.org/msg187936.html > > Eventually we figured out that it was a skb

On Sun, May 05, 2019 at 12:20:24PM +0800, Jason Wang wrote: > > On 2019/4/26 ??3:35, Jason Wang wrote: > > > > On 2019/4/26 ??1:52, Michael S. Tsirkin wrote: > > > On Thu, Apr 25, 2019 at 03:33:19AM -0400, Jason Wang wrote: > > > > When the rx buffer is too small for a packet, we will discard the vq > > > > descriptor and retry it for the next

On Sun, May 05, 2019 at 12:20:24PM +0800, Jason Wang wrote: > > On 2019/4/26 ??3:35, Jason Wang wrote: > > > > On 2019/4/26 ??1:52, Michael S. Tsirkin wrote: > > > On Thu, Apr 25, 2019 at 03:33:19AM -0400, Jason Wang wrote: > > > > When the rx buffer is too small for a packet, we will discard the vq > > > > descriptor and retry it for the next

From: Al Viro <viro at zeniv.linux.org.uk> Cc: Michael S. Tsirkin <mst at redhat.com> Cc: kvm at vger.kernel.org Cc: virtualization at lists.linux-foundation.org Signed-off-by: Al Viro <viro at zeniv.linux.org.uk> --- drivers/vhost/net.c | 82 +++++++++++++++-------------------------------------- include/linux/uio.h | 3 -- lib/iovec.c | 26 ----------------- 3 files