[dpdk-dev] OVDK userspace vhost : Issue with VIRTIO_RING_F_INDIRECT_DESC capability

[sai kiran]

Hi,

I am using OVDK userspace-vhost interfaces for VM-to-external communication
and facing an issue with them.

I am using the topology mentioned in
https://github.com/01org/dpdk-ovs/blob/development/docs/04_Sample_Configurations/02_Userspace-vHost.md
But the Guest is a Freebsd VM and our own custom userspace virtio drivers.
Guest does not have DPDK.


   1. I could start OVDK application and vswitchd, and provision a FreeBSD
   Guest VM with two userspace-vhost interfaces.
   2. These two userspace-vhost interfaces do not have
VIRTIO_RING_F_INDIRECT_DESC
   capability negotiated from backend OVDK-Qemu
   3. Inside the freebsd VM, i have my own userspace drivers running, which
   make use of indirect descriptors of virtio.
   4. *Question 1* : By default, without INDIRECT descriptor capability, my
   drivers fail to run.    Is there any way to increase ring size of
   virtio?     This can help us  avoid using indirect descriptors because of
   more space in the ring
   5. *Question 2*: When I try to set the capability from backend QEMU,
   guest drivers do not see any packets reaching the guest.     Is there
   any way to resolve this ??

Any help/suggestion would be of great help.

*Thanks & Regards,*
*Saikiran V*