Re: [PATCH v2 0/5] KVM: x86: X86_FEATURE bit() cleanup

From: Paolo Bonzini
Date: Wed Jan 15 2020 - 13:07:56 EST


On 17/12/19 22:32, Sean Christopherson wrote:
> Small series to add build-time protections on reverse CPUID lookup (and
> other usages of bit()), and to rename the misleading-generic bit() helper
> to something that better conveys its purpose.
>
> I don't love emulator changes in patch 1 as adding one-off helpers is a
> bit silly, but IMO it's the lesser of two evils, e.g. adding dedicated
> helpers is arguably less error prone than manually encoding a CPUID
> lookup, and the helpers approach avoids having to include cpuid.h in the
> emulator code.
>
> v2:
> - Rework the assertions to use the reverse_cpuid table instead of
> using the last cpufeatures word (which was not at all intuitive).
>
> Sean Christopherson (5):
> KVM: x86: Add dedicated emulator helpers for querying CPUID features
> KVM: x86: Move bit() helper to cpuid.h
> KVM: x86: Add CPUID_7_1_EAX to the reverse CPUID table
> KVM: x86: Expand build-time assertion on reverse CPUID usage
> KVM: x86: Refactor and rename bit() to feature_bit() macro
>
> arch/x86/include/asm/kvm_emulate.h | 4 +++
> arch/x86/kvm/cpuid.c | 5 ++--
> arch/x86/kvm/cpuid.h | 41 +++++++++++++++++++++++++----
> arch/x86/kvm/emulate.c | 21 +++------------
> arch/x86/kvm/svm.c | 4 +--
> arch/x86/kvm/vmx/vmx.c | 42 +++++++++++++++---------------
> arch/x86/kvm/x86.c | 18 +++++++++++++
> arch/x86/kvm/x86.h | 5 ----
> 8 files changed, 87 insertions(+), 53 deletions(-)
>

Queued, thanks.

Paolo