On 7/29/21 8:02 AM, Tianyu Lan wrote:

quoted

There is x86_hyper_type to identify hypervisor type and we may check
this variable after checking X86_FEATURE_HYPERVISOR.

static inline bool hv_is_isolation_supported(void)
{
    if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
        return 0;

        if (x86_hyper_type != X86_HYPER_MS_HYPERV)
                return 0;

    // out of line function call:
    return __hv_is_isolation_supported();
}   

Looks fine.  You just might want to use this existing helper:

static inline bool hypervisor_is_type(enum x86_hypervisor_type type)
{
        return x86_hyper_type == type;
}