On Mon, Oct 28, 2024 at 04:48:18PM +0000, Peter Maydell wrote: > On Mon, 28 Oct 2024 at 16:35, Daniel P. Berrangé <berra...@redhat.com> wrote: > > > > On Mon, Oct 28, 2024 at 04:16:31PM +0000, Peter Maydell wrote: > > > On Fri, 25 Oct 2024 at 14:24, Daniel P. Berrangé <berra...@redhat.com> > > > wrote: > > > > On Fri, Oct 25, 2024 at 03:18:25PM +0200, Eric Auger wrote: > > > > > On 10/25/24 15:06, Daniel P. Berrangé wrote: > > > > > > Also, is this naming convention really the same one that users > > > > > > will see when they look at /proc/cpuinfo to view features ? It > > > > > No it is not. I do agree that the custom cpu model is very low level. > > > > > It > > > > > is very well suited to test all series turning ID regs as writable but > > > > > this would require an extra layer that adapts /proc/cpuinfo feature > > > > > level to this regid/field abstraction. > > > > > > > > > > In /cpu/proc you will see somethink like: > > > > > Features : fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics fphp > > > > > asimdhp cpuid asimdrdm lrcpc dcpop asimddp > > > > > > > > Right, IMHO, this is the terminology that QEMU must use in user > > > > facing APIs. > > > > > > /proc/cpuinfo's naming is rather weird for historical > > > reasons (for instance there is only one FEAT_FP16 feature > > > but cpuinfo lists "fphp" and "asimdhp" separately). > > > > There's plenty of wierd history in x86 too. In this > > case I might suggest just picking one of the two > > common names, and ignoring the other. > > > > If we really wanted to, we could alias the 2nd name > > to the first, but its likely not worth the bother. > > Or we could use the standard set of architectural > feature names, and not have the problem at all, and not > have to document what we mean by our nonstandard names.
+1 There's existing documentation [*] for the standard feature names, which provides: - A short description of what the feature does - Any dependencies a particular feature has (e.g.FEAT_VHE implies FEAT_LSE, FEAT_Debugv8p1, and FEAT_AA64EL2) - The register fields/values that are used to discover the feature. This seems like the most user-friendly option... [*]: https://developer.arm.com/documentation/109697/2024_09 -- Thanks, Oliver
