Re: [PATCH v3 3/4] KVM: x86: Tie Intel and AMD behavior for MSR_TSC_AUX to guest CPU model

Sean Christopherson
2021-04-27T21:58:41Z

On Mon, Apr 26, 2021, Reiji Watanabe wrote:

> > There is also a kernel bug lurking; vgetcpu_cpu_init() doesn't check
> > X86_FEATURE_RDPID and will fail to initialize MSR_TSC_AUX if RDPID is supported
> > but RDTSCP is not, and __getcpu() uses RDPID. I'll verify that's broken and
> > send a patch for that one too.
>
> I don't find vgetcpu_cpu_init() or __getcpu() in
> https://github.com/torvalds/linux.
> I would assume you meant setup_getcpu() and vdso_read_cpunode() instead (?).

Ya, I was looking at an old kernel when I typed that up. Bug is still there
though :-)