On Fri, Oct 25 2024, Daniel P. Berrangé <berra...@redhat.com> wrote:
> On Fri, Oct 25, 2024 at 03:18:25PM +0200, Eric Auger wrote: >> Hi Daniel, >> >> On 10/25/24 15:06, Daniel P. Berrangé wrote: >> > On Fri, Oct 25, 2024 at 12:17:37PM +0200, Eric Auger wrote: >> >> At the moment, the custom model does not support legacy options >> >> of the host cpu model. We need to understand what we do with those >> >> latter (SVE, ...). This means that related KVM ioctl are >> >> not called yet. >> > It will be pretty painful to have to use different feature >> > terminology for different CPU models. Everything in libvirt >> > assuming feature terminology varies per-arch, not per-CPU >> > model. >> Actually as far as I understand those regids/fields would fit all kind >> of aarch64 Cortex-A CPUs. So they wouldn't vary per-CPU (I mean their >> terminology. Their availability will). > > What I mean is can we define named models for various different > vendor's Cortex-A silicon and just use that without needing to > toggle features, except in rare cases. I'm not sure whether creating named models for various cpus would actually scale; what we probably could do is come up with some Armv8.6, Armv8.7, ... models and have additional models for some well-known cpus. That would also give us some basic sanity checks for feature combinations, if we do not want to support completely custom frankencpus.
