On 2018?10?13? 01:23, Michael S. Tsirkin wrote:> On Fri, Oct 12, 2018 at 10:32:44PM +0800, Tiwei Bie wrote: >> On Mon, Jul 16, 2018 at 11:28:09AM +0800, Jason Wang wrote: >> [...] >>> @@ -1367,10 +1397,48 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg >>> vq->last_avail_idx = s.num; >>> /* Forget the cached index value. */ >>> vq->avail_idx = vq->last_avail_idx; >>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { >>> + vq->last_avail_wrap_counter = wrap_counter; >>> + vq->avail_wrap_counter = vq->last_avail_wrap_counter; >>> + } >>> break; >>> case VHOST_GET_VRING_BASE: >>> s.index = idx; >>> s.num = vq->last_avail_idx; >>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) >>> + s.num |= vq->last_avail_wrap_counter << 31; >>> + if (copy_to_user(argp, &s, sizeof(s))) >>> + r = -EFAULT; >>> + break; >>> + case VHOST_SET_VRING_USED_BASE: >>> + /* Moving base with an active backend? >>> + * You don't want to do that. >>> + */ >>> + if (vq->private_data) { >>> + r = -EBUSY; >>> + break; >>> + } >>> + if (copy_from_user(&s, argp, sizeof(s))) { >>> + r = -EFAULT; >>> + break; >>> + } >>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { >>> + wrap_counter = s.num >> 31; >>> + s.num &= ~(1 << 31); >>> + } >>> + if (s.num > 0xffff) { >>> + r = -EINVAL; >>> + break; >>> + } >> Do we want to put wrap_counter at bit 15? > I think I second that - seems to be consistent with > e.g. event suppression structure and the proposed > extension to driver notifications.Ok, I assumes packed virtqueue support 64K but looks not. I can change it to bit 15 and GET_VRING_BASE need to be changed as well.> > >> If put wrap_counter at bit 31, the check (s.num > 0xffff) >> won't be able to catch the illegal index 0x8000~0xffff for >> packed ring. >>Do we need to clarify this in the spec?>>> + vq->last_used_idx = s.num; >>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) >>> + vq->last_used_wrap_counter = wrap_counter; >>> + break; >>> + case VHOST_GET_VRING_USED_BASE: >> Do we need the new VHOST_GET_VRING_USED_BASE and >> VHOST_SET_VRING_USED_BASE ops? >> >> We are going to merge below series in DPDK: >> >> http://patches.dpdk.org/patch/45874/ >> >> We may need to reach an agreement first.If we agree that 64K virtqueue won't be supported, I'm ok with either. Btw the code assumes used_wrap_counter is equal to avail_wrap_counter which looks wrong? Thanks>> >>> + s.index = idx; >>> + s.num = vq->last_used_idx; >>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) >>> + s.num |= vq->last_used_wrap_counter << 31; >>> if (copy_to_user(argp, &s, sizeof s)) >>> r = -EFAULT; >>> break; >> [...]
Michael S. Tsirkin
2018-Oct-15 02:43 UTC
[PATCH net-next V2 6/8] vhost: packed ring support
On Mon, Oct 15, 2018 at 10:22:33AM +0800, Jason Wang wrote:> > > On 2018?10?13? 01:23, Michael S. Tsirkin wrote: > > On Fri, Oct 12, 2018 at 10:32:44PM +0800, Tiwei Bie wrote: > > > On Mon, Jul 16, 2018 at 11:28:09AM +0800, Jason Wang wrote: > > > [...] > > > > @@ -1367,10 +1397,48 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg > > > > vq->last_avail_idx = s.num; > > > > /* Forget the cached index value. */ > > > > vq->avail_idx = vq->last_avail_idx; > > > > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { > > > > + vq->last_avail_wrap_counter = wrap_counter; > > > > + vq->avail_wrap_counter = vq->last_avail_wrap_counter; > > > > + } > > > > break; > > > > case VHOST_GET_VRING_BASE: > > > > s.index = idx; > > > > s.num = vq->last_avail_idx; > > > > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > > > > + s.num |= vq->last_avail_wrap_counter << 31; > > > > + if (copy_to_user(argp, &s, sizeof(s))) > > > > + r = -EFAULT; > > > > + break; > > > > + case VHOST_SET_VRING_USED_BASE: > > > > + /* Moving base with an active backend? > > > > + * You don't want to do that. > > > > + */ > > > > + if (vq->private_data) { > > > > + r = -EBUSY; > > > > + break; > > > > + } > > > > + if (copy_from_user(&s, argp, sizeof(s))) { > > > > + r = -EFAULT; > > > > + break; > > > > + } > > > > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { > > > > + wrap_counter = s.num >> 31; > > > > + s.num &= ~(1 << 31); > > > > + } > > > > + if (s.num > 0xffff) { > > > > + r = -EINVAL; > > > > + break; > > > > + } > > > Do we want to put wrap_counter at bit 15? > > I think I second that - seems to be consistent with > > e.g. event suppression structure and the proposed > > extension to driver notifications. > > Ok, I assumes packed virtqueue support 64K but looks not. I can change it to > bit 15 and GET_VRING_BASE need to be changed as well. > > > > > > > > If put wrap_counter at bit 31, the check (s.num > 0xffff) > > > won't be able to catch the illegal index 0x8000~0xffff for > > > packed ring. > > > > > Do we need to clarify this in the spec?Isn't this all internal vhost stuff?> > > > + vq->last_used_idx = s.num; > > > > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > > > > + vq->last_used_wrap_counter = wrap_counter; > > > > + break; > > > > + case VHOST_GET_VRING_USED_BASE: > > > Do we need the new VHOST_GET_VRING_USED_BASE and > > > VHOST_SET_VRING_USED_BASE ops? > > > > > > We are going to merge below series in DPDK: > > > > > > http://patches.dpdk.org/patch/45874/ > > > > > > We may need to reach an agreement first. > > If we agree that 64K virtqueue won't be supported, I'm ok with either.Well the spec says right at the beginning: Packed virtqueues support up to 2 15 entries each.> Btw the code assumes used_wrap_counter is equal to avail_wrap_counter which > looks wrong? > > Thanks > > > > > > > > + s.index = idx; > > > > + s.num = vq->last_used_idx; > > > > + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) > > > > + s.num |= vq->last_used_wrap_counter << 31; > > > > if (copy_to_user(argp, &s, sizeof s)) > > > > r = -EFAULT; > > > > break; > > > [...]
On 2018?10?15? 10:43, Michael S. Tsirkin wrote:> On Mon, Oct 15, 2018 at 10:22:33AM +0800, Jason Wang wrote: >> >> On 2018?10?13? 01:23, Michael S. Tsirkin wrote: >>> On Fri, Oct 12, 2018 at 10:32:44PM +0800, Tiwei Bie wrote: >>>> On Mon, Jul 16, 2018 at 11:28:09AM +0800, Jason Wang wrote: >>>> [...] >>>>> @@ -1367,10 +1397,48 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg >>>>> vq->last_avail_idx = s.num; >>>>> /* Forget the cached index value. */ >>>>> vq->avail_idx = vq->last_avail_idx; >>>>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { >>>>> + vq->last_avail_wrap_counter = wrap_counter; >>>>> + vq->avail_wrap_counter = vq->last_avail_wrap_counter; >>>>> + } >>>>> break; >>>>> case VHOST_GET_VRING_BASE: >>>>> s.index = idx; >>>>> s.num = vq->last_avail_idx; >>>>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) >>>>> + s.num |= vq->last_avail_wrap_counter << 31; >>>>> + if (copy_to_user(argp, &s, sizeof(s))) >>>>> + r = -EFAULT; >>>>> + break; >>>>> + case VHOST_SET_VRING_USED_BASE: >>>>> + /* Moving base with an active backend? >>>>> + * You don't want to do that. >>>>> + */ >>>>> + if (vq->private_data) { >>>>> + r = -EBUSY; >>>>> + break; >>>>> + } >>>>> + if (copy_from_user(&s, argp, sizeof(s))) { >>>>> + r = -EFAULT; >>>>> + break; >>>>> + } >>>>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { >>>>> + wrap_counter = s.num >> 31; >>>>> + s.num &= ~(1 << 31); >>>>> + } >>>>> + if (s.num > 0xffff) { >>>>> + r = -EINVAL; >>>>> + break; >>>>> + } >>>> Do we want to put wrap_counter at bit 15? >>> I think I second that - seems to be consistent with >>> e.g. event suppression structure and the proposed >>> extension to driver notifications. >> Ok, I assumes packed virtqueue support 64K but looks not. I can change it to >> bit 15 and GET_VRING_BASE need to be changed as well. >> >>> >>>> If put wrap_counter at bit 31, the check (s.num > 0xffff) >>>> won't be able to catch the illegal index 0x8000~0xffff for >>>> packed ring. >>>> >> Do we need to clarify this in the spec? > Isn't this all internal vhost stuff?I meant the illegal index 0x8000-0xffff.> >>>>> + vq->last_used_idx = s.num; >>>>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) >>>>> + vq->last_used_wrap_counter = wrap_counter; >>>>> + break; >>>>> + case VHOST_GET_VRING_USED_BASE: >>>> Do we need the new VHOST_GET_VRING_USED_BASE and >>>> VHOST_SET_VRING_USED_BASE ops? >>>> >>>> We are going to merge below series in DPDK: >>>> >>>> http://patches.dpdk.org/patch/45874/ >>>> >>>> We may need to reach an agreement first. >> If we agree that 64K virtqueue won't be supported, I'm ok with either. > Well the spec says right at the beginning: > > Packed virtqueues support up to 2 15 entries each.Ok. I get it. Then I can change vhost to match what dpdk did. Thanks> > >> Btw the code assumes used_wrap_counter is equal to avail_wrap_counter which >> looks wrong? >> >> Thanks >> >>>>> + s.index = idx; >>>>> + s.num = vq->last_used_idx; >>>>> + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) >>>>> + s.num |= vq->last_used_wrap_counter << 31; >>>>> if (copy_to_user(argp, &s, sizeof s)) >>>>> r = -EFAULT; >>>>> break; >>>> [...]