Thomas: Could we roll back that commit or apply Changchun's patch? /Huawei
On 7/1/2015 11:53 PM, Xie, Huawei wrote: > On 7/1/2015 3:49 PM, Ouyang Changchun wrote: >> This commit breaks virtio basic packets rx functionality: >> d78deadae4dca240e85054bf2d604a801676becc >> >> The QEMU use 256 as default vring size, also use this default value to >> calculate the virtio >> avail ring base address and used ring base address, and vhost in the backend >> use the ring base >> address to do packet IO. >> >> Virtio spec also says the queue size in PCI configuration is read-only, so >> virtio front end >> can't change it. just need use the read-only value to allocate space for >> vring and calculate the >> avail and used ring base address. Otherwise, the avail and used ring base >> address will be different >> between host and guest, accordingly, packet IO can't work normally. > virtio driver could still use the vq_size to initialize avail ring and > use ring so that they still have the same base address. > The other issue is vhost use index & (vq->size -1) to index the ring. > > > Thomas: > This fix works but introduces slight change with original code. Could we > just rollback that commit? > > d78deadae4dca240e85054bf2d604a801676becc > > >> Signed-off-by: Changchun Ouyang <changchun.ouyang at intel.com> >> --- >> drivers/net/virtio/virtio_ethdev.c | 14 +++----------- >> 1 file changed, 3 insertions(+), 11 deletions(-) >> >> > >
