Avi Kivity <a...@redhat.com> writes: > On 10/09/2012 05:16 AM, Rusty Russell wrote: >> Anthony Liguori <aligu...@us.ibm.com> writes: >>> We'll never remove legacy so we shouldn't plan on it. There are >>> literally hundreds of thousands of VMs out there with the current virtio >>> drivers installed in them. We'll be supporting them for a very, very >>> long time :-) >> >> You will be supporting this for qemu on x86, sure. As I think we're >> still in the growth phase for virtio, I prioritize future spec >> cleanliness pretty high. > > If a pure ppc hypervisor was on the table, this might have been > worthwhile. As it is the codebase is shared, and the Linux drivers are > shared, so cleaning up the spec doesn't help the code.
Note that distros have been (perhaps unknowingly) shipping virtio-pci for PPC for some time now. So even though there wasn't a hypervisor that supported virtio-pci, the guests already support it and are out there in the wild. There's a lot of value in maintaining "legacy" support even for PPC. >> But I think you'll be surprised how fast this is deprecated: >> 1) Bigger queues for block devices (guest-specified ringsize) >> 2) Smaller rings for openbios (guest-specified alignment) >> 3) All-mmio mode (powerpc) >> 4) Whatever network features get numbers > 31. >> >>> I don't think we gain a lot by moving the ISR into a separate BAR. >>> Splitting up registers like that seems weird to me too. >> >> Confused. I proposed the same split as you have, just ISR by itself. > > I believe Anthony objects to having the ISR by itself. What is the > motivation for that? Right, BARs are a precious resource not to be spent lightly. Having an entire BAR dedicated to a 1-byte register seems like a waste to me. Regards, Anthony Liguori > > > -- > error compiling committee.c: too many arguments to function > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
