On 03/15/2012 01:47 PM, Stefan Hajnoczi wrote: > On Thu, Mar 15, 2012 at 9:02 AM, Dmitry Fleytman > <dmitry.fleyt...@ravellosystems.com> wrote: > > Below is the implementation of VMWare PVSCSI device and > > command line parameters to configure vendor name and product name > > for SCSI storage are implemented. > > Latter is needed to make PVSCSI storage devices look exactly as > > on VMWare hypervisors. > > > > With this and VMWARE3 patches V2V migration problem for VMWare > > images should be solved relatively easy. > > What is the V2V strategy? > > Supporting these devices is fine if we have a way to convert guests to > use virtio. But if the plan is to keep the guests on VMware pv > devices, then that will split the development effort on support and > optimizing I/O devices. All the performance work going into > virtio-net (vhost-net), virtio-blk, and possibly virtio-scsi isn't > easy to duplicate for VMware pv devices. Also, we cannot extend > VMware devices easily while retaining compatibility. >
Note, it's possible to hook vmxnet to vhost-net: - process the vmxnet ring in qemu - translate it into a virtio ring in offguest memory (placing virtio headers in offguest memory as well) - fire off vhost-net - etc. So there are still extra context switches, but we can still get some of the benefits of vhost-net. -- error compiling committee.c: too many arguments to function