search for: virtq_

...;re right! The BUG_ON() isn't right. I'll remove it. And I think something related to this in the spec isn't very clear currently. In the spec, there are below words: https://github.com/oasis-tcs/virtio-spec/blob/d4fec517dfcf/packed-ring.tex#L272 """ In descriptors with VIRTQ_DESC_F_INDIRECT set VIRTQ_DESC_F_WRITE is reserved and is ignored by the device. """ So when device writes back an used descriptor in this case, device may not set the VIRTQ_DESC_F_WRITE flag as the flag is reserved and should be ignored. https://github.com/oasis-tcs/virtio-spec/blo...

...;re right! The BUG_ON() isn't right. I'll remove it. And I think something related to this in the spec isn't very clear currently. In the spec, there are below words: https://github.com/oasis-tcs/virtio-spec/blob/d4fec517dfcf/packed-ring.tex#L272 """ In descriptors with VIRTQ_DESC_F_INDIRECT set VIRTQ_DESC_F_WRITE is reserved and is ignored by the device. """ So when device writes back an used descriptor in this case, device may not set the VIRTQ_DESC_F_WRITE flag as the flag is reserved and should be ignored. https://github.com/oasis-tcs/virtio-spec/blo...

...ed_idx; > + flags = virtio16_to_cpu(vq->vq.vdev, > + vq->vring_packed.desc[last_used].flags); > + avail = flags & VRING_DESC_F_AVAIL(1); > + used = flags & VRING_DESC_F_USED(1); > + > + return avail == used; > +} This looks interesting, spec said: " Thus VIRTQ_DESC_F_AVAIL and VIRTQ_DESC_F_USED bits are different for an available descriptor and equal for a used descriptor. Note that this observation is mostly useful for sanity-checking as these are necessary but not sufficient conditions - for example, all descriptors are zero-initialized. To detect us...

...nk something related to this in the spec isn't very > > clear currently. > > > > In the spec, there are below words: > > > > https://github.com/oasis-tcs/virtio-spec/blob/d4fec517dfcf/packed-ring.tex#L272 > > """ > > In descriptors with VIRTQ_DESC_F_INDIRECT set VIRTQ_DESC_F_WRITE > > is reserved and is ignored by the device. > > """ > > > > So when device writes back an used descriptor in this case, > > device may not set the VIRTQ_DESC_F_WRITE flag as the flag > > is reserved and shou...

...nk something related to this in the spec isn't very > > clear currently. > > > > In the spec, there are below words: > > > > https://github.com/oasis-tcs/virtio-spec/blob/d4fec517dfcf/packed-ring.tex#L272 > > """ > > In descriptors with VIRTQ_DESC_F_INDIRECT set VIRTQ_DESC_F_WRITE > > is reserved and is ignored by the device. > > """ > > > > So when device writes back an used descriptor in this case, > > device may not set the VIRTQ_DESC_F_WRITE flag as the flag > > is reserved and shou...

...t. I'll remove it. > And I think something related to this in the spec isn't very > clear currently. > > In the spec, there are below words: > > https://github.com/oasis-tcs/virtio-spec/blob/d4fec517dfcf/packed-ring.tex#L272 > """ > In descriptors with VIRTQ_DESC_F_INDIRECT set VIRTQ_DESC_F_WRITE > is reserved and is ignored by the device. > """ > > So when device writes back an used descriptor in this case, > device may not set the VIRTQ_DESC_F_WRITE flag as the flag > is reserved and should be ignored. > > https:...

...spec isn't very > > > clear currently. > > > > > > In the spec, there are below words: > > > > > > https://github.com/oasis-tcs/virtio-spec/blob/d4fec517dfcf/packed-ring.tex#L272 > > > """ > > > In descriptors with VIRTQ_DESC_F_INDIRECT set VIRTQ_DESC_F_WRITE > > > is reserved and is ignored by the device. > > > """ > > > > > > So when device writes back an used descriptor in this case, > > > device may not set the VIRTQ_DESC_F_WRITE flag as the flag >...

...> clear currently. > > > > > > > > In the spec, there are below words: > > > > > > > > https://github.com/oasis-tcs/virtio-spec/blob/d4fec517dfcf/packed-ring.tex#L272 > > > > """ > > > > In descriptors with VIRTQ_DESC_F_INDIRECT set VIRTQ_DESC_F_WRITE > > > > is reserved and is ignored by the device. > > > > """ > > > > > > > > So when device writes back an used descriptor in this case, > > > > device may not set the VIRTQ_DESC_F_WRI...

...> clear currently. > > > > > > > > In the spec, there are below words: > > > > > > > > https://github.com/oasis-tcs/virtio-spec/blob/d4fec517dfcf/packed-ring.tex#L272 > > > > """ > > > > In descriptors with VIRTQ_DESC_F_INDIRECT set VIRTQ_DESC_F_WRITE > > > > is reserved and is ignored by the device. > > > > """ > > > > > > > > So when device writes back an used descriptor in this case, > > > > device may not set the VIRTQ_DESC_F_WRI...

Hello everyone, This RFC implements packed ring support for virtio driver. The code was tested with DPDK vhost (testpmd/vhost-PMD) implemented by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html Minor changes are needed for the vhost code, e.g. to kick the guest. TODO: - Refinements and bug fixes; - Split into small patches; - Test indirect descriptor support; - Test/fix event

Hello everyone, This RFC implements packed ring support for virtio driver. The code was tested with DPDK vhost (testpmd/vhost-PMD) implemented by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html Minor changes are needed for the vhost code, e.g. to kick the guest. TODO: - Refinements and bug fixes; - Split into small patches; - Test indirect descriptor support; - Test/fix event