Re: [PATCH v2 08/10] target/i386/kvm: reset AMD PMU registers during VM reset

[Francesco Lavra <flavra@baylibre.com>]

On 2025-03-02 at 22:00, Dongli Zhang wrote:
> +static bool is_same_vendor(CPUX86State *env)
> +{
> +    static uint32_t host_cpuid_vendor1;
> +    static uint32_t host_cpuid_vendor2;
> +    static uint32_t host_cpuid_vendor3;

What's the purpose of making these variables static?

> +    host_cpuid(0x0, 0, NULL, &host_cpuid_vendor1,
> &host_cpuid_vendor3,
> +               &host_cpuid_vendor2);
> +
> +    return env->cpuid_vendor1 == host_cpuid_vendor1 &&
> +           env->cpuid_vendor2 == host_cpuid_vendor2 &&
> +           env->cpuid_vendor3 == host_cpuid_vendor3;
> +}
> +
> +static void kvm_init_pmu_info(CPUState *cs)
> +{
> +    X86CPU *cpu = X86_CPU(cs);
> +    CPUX86State *env = &cpu->env;
> +
> +    /*
> +     * The PMU virtualization is disabled by kvm.enable_pmu=N.
> +     */
> +    if (kvm_pmu_disabled) {
> +        return;
> +    }
> +
> +    /*
> +     * It is not supported to virtualize AMD PMU registers on Intel
> +     * processors, nor to virtualize Intel PMU registers on AMD
> processors.
> +     */
> +    if (!is_same_vendor(env)) {
> +        return;
> +    }
> +
> +    /*
> +     * If KVM_CAP_PMU_CAPABILITY is not supported, there is no way
> to
> +     * disable the AMD pmu virtualization.

s/pmu/PMU/