On Wed, May 16, 2018 at 08:32:20PM +0800, Jason Wang wrote:> Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > drivers/vhost/net.c | 3 +- > drivers/vhost/vhost.c | 539 ++++++++++++++++++++++++++++++++++++++++++++++---- > drivers/vhost/vhost.h | 8 +- > 3 files changed, 513 insertions(+), 37 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 8304c30..f2a0f5b 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -1358,6 +1382,8 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg > break; > } > vq->last_avail_idx = s.num; > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > + vq->avail_wrap_counter = s.num >> 31; > /* Forget the cached index value. */ > vq->avail_idx = vq->last_avail_idx; > break; > @@ -1366,6 +1392,8 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg > s.num = vq->last_avail_idx; > if (copy_to_user(argp, &s, sizeof s)) > r = -EFAULT; > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > + s.num |= vq->avail_wrap_counter << 31; > break; > case VHOST_SET_VRING_ADDR: > if (copy_from_user(&a, argp, sizeof a)) {'last_used_idx' also needs to be saved/restored here. I have figured out the root cause of broken device after reloading 'virtio-net' module, all indices have been reset for a reloading but 'last_used_idx' is not properly reset in this case. This confuses handle_rx()/tx(). Wei
On 2018?05?23? 00:54, Wei Xu wrote:> On Wed, May 16, 2018 at 08:32:20PM +0800, Jason Wang wrote: >> Signed-off-by: Jason Wang <jasowang at redhat.com> >> --- >> drivers/vhost/net.c | 3 +- >> drivers/vhost/vhost.c | 539 ++++++++++++++++++++++++++++++++++++++++++++++---- >> drivers/vhost/vhost.h | 8 +- >> 3 files changed, 513 insertions(+), 37 deletions(-) >> >> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c >> index 8304c30..f2a0f5b 100644 >> --- a/drivers/vhost/vhost.c >> +++ b/drivers/vhost/vhost.c >> @@ -1358,6 +1382,8 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg >> break; >> } >> vq->last_avail_idx = s.num; >> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) >> + vq->avail_wrap_counter = s.num >> 31; >> /* Forget the cached index value. */ >> vq->avail_idx = vq->last_avail_idx; >> break; >> @@ -1366,6 +1392,8 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg >> s.num = vq->last_avail_idx; >> if (copy_to_user(argp, &s, sizeof s)) >> r = -EFAULT; >> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) >> + s.num |= vq->avail_wrap_counter << 31; >> break; >> case VHOST_SET_VRING_ADDR: >> if (copy_from_user(&a, argp, sizeof a)) { > 'last_used_idx' also needs to be saved/restored here. > > I have figured out the root cause of broken device after reloading > 'virtio-net' module, all indices have been reset for a reloading but > 'last_used_idx' is not properly reset in this case. This confuses > handle_rx()/tx(). > > Wei >Good catch, so we probably need a new ioctl to sync between qemu and vhost. Something like VHOST_SET/GET_USED_BASE. Thanks
On Wed, May 23, 2018 at 09:39:28AM +0800, Jason Wang wrote:> > > On 2018?05?23? 00:54, Wei Xu wrote: > >On Wed, May 16, 2018 at 08:32:20PM +0800, Jason Wang wrote: > >>Signed-off-by: Jason Wang <jasowang at redhat.com> > >>--- > >> drivers/vhost/net.c | 3 +- > >> drivers/vhost/vhost.c | 539 ++++++++++++++++++++++++++++++++++++++++++++++---- > >> drivers/vhost/vhost.h | 8 +- > >> 3 files changed, 513 insertions(+), 37 deletions(-) > >> > >>diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > >>index 8304c30..f2a0f5b 100644 > >>--- a/drivers/vhost/vhost.c > >>+++ b/drivers/vhost/vhost.c > >>@@ -1358,6 +1382,8 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg > >> break; > >> } > >> vq->last_avail_idx = s.num; > >>+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > >>+ vq->avail_wrap_counter = s.num >> 31; > >> /* Forget the cached index value. */ > >> vq->avail_idx = vq->last_avail_idx; > >> break; > >>@@ -1366,6 +1392,8 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg > >> s.num = vq->last_avail_idx; > >> if (copy_to_user(argp, &s, sizeof s)) > >> r = -EFAULT; > >>+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > >>+ s.num |= vq->avail_wrap_counter << 31; > >> break; > >> case VHOST_SET_VRING_ADDR: > >> if (copy_from_user(&a, argp, sizeof a)) { > >'last_used_idx' also needs to be saved/restored here. > > > >I have figured out the root cause of broken device after reloading > >'virtio-net' module, all indices have been reset for a reloading but > >'last_used_idx' is not properly reset in this case. This confuses > >handle_rx()/tx(). > > > >Wei > > > > Good catch, so we probably need a new ioctl to sync between qemu and vhost. > > Something like VHOST_SET/GET_USED_BASE.Sure, or can we expand 'vhost_vring_state' to keep them done in a bunch?> > Thanks >