Re: [Qemu-devel] [virtio-dev] [PATCH v3 0/7] Vhost-pci for inter-VM communication

["Avi Cohen (A)" <avi.cohen@huawei.com>]

> -----Original Message-----
> From: Jason Wang [mailto:jasowang@redhat.com]
> Sent: Tuesday, 05 December, 2017 9:19 AM
> To: Wei Wang; virtio-dev@lists.oasis-open.org; qemu-devel@nongnu.org;
> mst@redhat.com; marcandre.lureau@redhat.com; stefanha@redhat.com;
> pbonzini@redhat.com
> Cc: jan.kiszka@siemens.com; Avi Cohen (A); zhiyong.yang@intel.com
> Subject: Re: [virtio-dev] [PATCH v3 0/7] Vhost-pci for inter-VM communication
> 
> 
> 
> On 2017年12月05日 15:15, Wei Wang wrote:
> > On 12/05/2017 03:01 PM, Jason Wang wrote:
> >>
> >>
> >> On 2017年12月05日 11:33, Wei Wang wrote:
> >>> Vhost-pci is a point-to-point based inter-VM communication solution.
> >>> This
> >>> patch series implements the vhost-pci-net device setup and
> >>> emulation. The device is implemented as a virtio device, and it is
> >>> set up via the vhost-user protocol to get the neessary info (e.g the
> >>> memory info of the remote VM, vring info).
> >>>
> >>> Currently, only the fundamental functions are implemented. More
> >>> features, such as MQ and live migration, will be updated in the
> >>> future.
> >>>
> >>> The DPDK PMD of vhost-pci has been posted to the dpdk mailinglist here:
> >>> http://dpdk.org/ml/archives/dev/2017-November/082615.html
> >>>
> >>> v2->v3 changes:
> >>> 1) static device creation: instead of creating and hot-plugging the
> >>>     device when receiving a vhost-user msg, the device is not
> >>> created
> >>>     via the qemu booting command line.
> >>> 2) remove vqs: rq and ctrlq are removed in this version.
> >>>      - receive vq: the receive vq is not needed anymore. The PMD
> >>> directly
> >>>                    shares the remote txq and rxq - grab from remote
> >>> txq to
> >>>                    receive packets, and put to rxq to send packets.
> >>>      - ctrlq: the ctrlq is replaced by the first 4KB metadata area
> >>> of the
> >>>               device Bar-2.
> >>> 3) simpler implementation: the entire implementation has been
> >>> tailored
> >>>     from ~1800 LOC to ~850 LOC.
> >>
> >> Hi:
> >>
> >> Any performance numbers you can share?
> >>
> >
> > Hi Jason,
> >
> > Performance testing and tuning on the data plane is in progress (btw,
> > that wouldn't affect the device part patches).
> > If possible, could we start the device part patch review in the meantime?
> >
> > Best,
> > Wei
> >
> 
> Hi Wei:
> 
> Will do, but basically, the cover lacks of the motivation for vhost-pci and I want
> to see some numbers first since I suspect it can over-perform exist data-path.
> 
> Thanks
[Avi Cohen (A)] 
Hi Wei
I can try testing to get **numbers**  - I can do it now , need a little help from you
I've started with downloading/building and installing  of > driver: https://github.com/wei-w-wang/vhost-pci-driver  to the kernel guest,
 **without**  downloading the 2nd patch > device: https://github.com/wei-w-wang/vhost-pci-device
But my guest kernel was corrupted after reboot (kernel panic/out of mem ..) -  can you tell me the steps to apply these patches ?
Best Regards
Avi