On Sat, Jul 01, 2023, Paolo Bonzini wrote:
> On Tue, Jun 27, 2023 at 2:33 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
> > - Fix a longstanding bug in the reporting of the number of entries returned by
> > KVM_GET_CPUID2
>
> This description does not match the actual commit which says there is
> no functional change. I have removed this entry from the merge commit,
> letting it go under "Misc cleanups".
Hmm, which commit are you looking at? This is the commit I was referring to in
the tag.
commit ab322c43cce97ff6d05439c9b72bf1513e3e1020
Author: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Fri May 26 14:03:39 2023 -0700
KVM: x86: Update number of entries for KVM_GET_CPUID2 on success, not failure
Update cpuid->nent if and only if kvm_vcpu_ioctl_get_cpuid2() succeeds.
The sole caller copies @cpuid to userspace only on success, i.e. the
existing code effectively does nothing.
Arguably, KVM should report the number of entries when returning -E2BIG so
that userspace doesn't have to guess the size, but all other similar KVM
ioctls() don't report the size either, i.e. userspace is conditioned to
guess.
