On Fri, 2024-05-17 at 10:39 -0700, Sean Christopherson wrote:
> Undefine SPEC_CTRL_SSBD, which is #defined by msr-index.h to represent the
> enable flag in MSR_IA32_SPEC_CTRL, to avoid issues with the macro being
> unpacked into its raw value when passed to KVM's F() macro. This will
> allow using multiple layers of macros in F() and friends, e.g. to harden
> against incorrect usage of F().
>
> No functional change intended (cpuid.c doesn't consume SPEC_CTRL_SSBD).
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/kvm/cpuid.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 8efffd48cdf1..a16d6e070c11 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -639,6 +639,12 @@ static __always_inline void kvm_cpu_cap_init(u32 leaf, u32 mask)
> kvm_cpu_caps[leaf] &= raw_cpuid_get(cpuid);
> }
>
> +/*
> + * Undefine the MSR bit macro to avoid token concatenation issues when
> + * processing X86_FEATURE_SPEC_CTRL_SSBD.
> + */
> +#undef SPEC_CTRL_SSBD
> +
> void kvm_set_cpu_caps(void)
> {
> memset(kvm_cpu_caps, 0, sizeof(kvm_cpu_caps));
Hi,
Maybe we should instead rename the
SPEC_CTRL_SSBD to 'MSR_IA32_SPEC_CTRL_SSBD' and together with it, other fields of this msr.
It seems that at least some msrs in this file do this.
Best regards,
Maxim Levitsky
