Re: [libvirt] CPU Support

CCing the AMD people who worked on this. On Wed, Jul 18, 2018 at 12:18:45PM +0200, Pavel Hrdina wrote: > On Wed, Jul 18, 2018 at 10:50:34AM +0100, Daniel P. Berrangé wrote: >> On Wed, Jul 18, 2018 at 12:41:48PM +0300, Hetz Ben Hamo wrote: >>> Hi, >>> >>> I've been looking at the CPU list and although I see lots of CPU's, I >>> cannot find 2 CPU families: >>> >>> * AMD Ryzen >>> * AMD Threadripper >>> >>> Although EPYC has been added recently. >>> >>> Are there any missing details which preventing adding those CPU's to the >>> list? >> Libvirt adds CPU models based on what QEMU supports. So from libvirt side the >> answer is simply that QEMU doesn't expose any models for Ryzen/Threadripper, >> but I'm not clear why it doesn't...

>> For a while I thought Ryzen/Threadripper would have same feature set as >> EPYC, but I've seen bugs recently suggesting that is not in fact the >> case. So it does look like having those models exposed by QEMU might >> be useful. >> >> Copy'ing QEMU devel & the CPU model maintainers for opinions. > I think that QEMU should figure out some pattern for naming CPU models > because it's one big mess. EPYC and Ryzen are bad names for QEMU as > Core/Xeon would be for Intel CPUs. It's the name of a model families > and it will probably remain the same but with different > microarchitecture. > Better name would be similarly like for the latest Inter CPUs, > Skylake-Client and Skylake-Server. Currently AMD has already two > microarchitectures, Zen and Zen+ and there is third one Zen 2 planned. > > Zen has AMD Ryzen, AMD Ryzen Threadripper and AMD Epyc. > Zen+ has AMD Ryzen, AMD Ryzen Threadripper > > And I bet that Zen 2 will follow the same model families.

> We probably cannot rename EPYC now, but before we introduce Ryzen and > Threadripper let's thing about it and come up with better names, for > example Zen-Client/Zen-Server Zen+-Client or something like that.