Re: [Qemu-devel] [PATCH] tcg/i386: Display AMD HT warning only for KVM

[Paolo Bonzini <pbonzini@redhat.com>]

On 29/03/2017 06:32, Pranith Kumar wrote:
> TCG uses the AMD cpu which warns when we use hyperthreading. Disable
> the warning for TCG since it is not necessary.
> 
> Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
> ---
>  target/i386/cpu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 7aa762245a..66242893b6 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -3647,7 +3647,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
>       * NOTE: the following code has to follow qemu_init_vcpu(). Otherwise
>       * cs->nr_threads hasn't be populated yet and the checking is incorrect.
>       */
> -    if (!IS_INTEL_CPU(env) && cs->nr_threads > 1 && !ht_warned) {
> +    if (!IS_INTEL_CPU(env) && cs->nr_threads > 1 && !ht_warned && kvm_enabled()) {
>          error_report("AMD CPU doesn't support hyperthreading. Please configure"
>                       " -smp options properly.");
>          ht_warned = true;

AMD Zen supports hyperthreading.  We should check if it uses the same
CPUID leaves and drop the if completely (but not in 2.9).

Paolo