Valeriy Vdovin <valeriy.vdovin@xxxxxxxxxxxxx> writes: > On Thu, Jun 17, 2021 at 07:22:36AM +0200, Markus Armbruster wrote: >> Valeriy Vdovin <valeriy.vdovin@xxxxxxxxxxxxx> writes: >> >> > Introducing new qapi method 'query-kvm-cpuid'. This method can be used to >> >> It's actually a QMP command. There are no "qapi methods". >> >> > get virtualized cpu model info generated by QEMU during VM initialization in >> > the form of cpuid representation. >> > >> > Diving into more details about virtual cpu generation: QEMU first parses '-cpu' >> >> virtual CPU >> >> > command line option. From there it takes the name of the model as the basis for >> > feature set of the new virtual cpu. After that it uses trailing '-cpu' options, >> > that state if additional cpu features should be present on the virtual cpu or >> > excluded from it (tokens '+'/'-' or '=on'/'=off'). >> > After that QEMU checks if the host's cpu can actually support the derived >> > feature set and applies host limitations to it. >> > After this initialization procedure, virtual cpu has it's model and >> > vendor names, and a working feature set and is ready for identification >> > instructions such as CPUID. >> > >> > Currently full output for this method is only supported for x86 cpus. >> >> Not sure about "currently": the interface looks quite x86-specific to me. >> > Yes, at some point I was thinking this interface could become generic, > but does not seem possible, so I'll remove this note. > >> The commit message doesn't mention KVM except in the command name. The >> schema provides the command only if defined(CONFIG_KVM). >> >> Can you explain why you need the restriction to CONFIG_KVM? >> > This CONFIG_KVM is used as a solution to a broken build if --disable-kvm > flag is set. I was choosing between this and writing empty implementation into > kvm-stub.c If the command only makes sense for KVM, then it's named correctly, but the commit message lacks a (brief!) explanation why it only makes for KVM. If it just isn't implemented for anything but KVM, then putting "kvm" into the command name is a bad idea. Also, the commit message should briefly note the restriction to KVM. Pick one :) [...]
