On 7/28/21 2:54 PM, Valeriy Vdovin wrote: > Introducing new QMP command 'query-x86-cpuid'. This command can be used to > 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' > 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. > > To learn exactly how virtual CPU is presented to the guest machine via CPUID > instruction, new QMP command can be used. By calling 'query-x86-cpuid' > command, one can get a full listing of all CPUID leaves with subleaves which > are > supported by the initialized virtual CPU. > > Other than debug, the command is useful in cases when we would like to > utilize QEMU's virtual CPU initialization routines and put the retrieved > values into kernel CPUID overriding mechanics for more precise control > over how various processes perceive its underlying hardware with > container processes as a good example. > > The command is specific to x86. It is currenly only implemented for KVM > acceleator. > > Output format: > The output is a plain list of leaf/subleaf argument combinations, that > return 4 words in registers EAX, EBX, ECX, EDX. > ...
> +## > +# @query-x86-cpuid: > +# > +# Returns raw data from the emulated CPUID table for the first VCPU. > +# The emulated CPUID table defines the response to the CPUID > +# instruction when executed by the guest operating system. > +# > +# Returns: a list of CpuidEntry > +# > +# Since: 6.1 > +## Unfortunately too late for 6.1, so you'll have to update that to "6.2" (also in @CpuidEntry).
