On Fri, Nov 13, 2015 at 03:50:16PM +0900, Tetsuya Mukawa wrote: > On 2015/11/13 14:32, Yuanhan Liu wrote: > > On Fri, Nov 13, 2015 at 02:20:29PM +0900, Tetsuya Mukawa wrote: > >> The patch introduces a new PMD. This PMD is implemented as thin wrapper > >> of librte_vhost. > >> > >> * Known issue. > >> We may see issues while handling RESET_OWNER message. > >> These handlings are done in vhost library, so not a part of vhost PMD. > >> So far, we are waiting for QEMU fixing. > > Fix patches have already been applied. Please help test :) > > > > --yliu > > Hi Yuanhan, > > It seems there might be an another issue related with "vq->callfd" in > vhost library. > We may miss something to handle the value correctly. > > Anyway, here are steps. > 1. Apply vhost PMD patch. > (I guess you don't need it to reproduce the issue, but to reproduce it, > using the PMD may be easy) > 2. Start testpmd on host with vhost-user PMD. > 3. Start QEMU with virtio-net device. > 4. Login QEMU. > 5. Bind the virtio-net device to igb_uio. > 6. Start testpmd in QEMU. > 7. Quit testmd in QEMU. > 8. Start testpmd again in QEMU. > > It seems when last command is executed, testpmd on host doesn't receive > SET_VRING_CALL message from QEMU. > Because of this, testpmd on host assumes virtio-net device is not ready. > (I made sure virtio_is_ready() was failed on host). > > According to QEMU source code, SET_VRING_KICK will be called when > virtqueue starts, but SET_VRING_CALL will be called when virtqueue is > initialized. > Not sure exactly, might be "vq->call" will be valid while connection is > established?
Yes, it would be valid as far as we don't reset it from another set_vring_call. So, we should not reset it on reset_device(). --yliu > > Also I've found a workaround. > Please execute after step7. > > 8. Bind the virtio-net device to virtio-pci kernel driver. > 9. Bind the virtio-net device to igb_uio. > 10. Start testpmd in QEMU. > > When step8 is executed, connection will be re-established, and testpmd > on host will be able to receive SET_VRING_CALL. > Then testpmd on host can start. > > Thanks, > Tetsuya