On Thu, Apr 26, 2018 at 11:26:49AM -0500, Babu Moger wrote:
> Remove generic non-intel check while validating hyperthreading support.
> Certain AMD CPUs can support hyperthreading now.
>
> CPU family with TOPOEXT feature can support hyperthreading now.
>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> Tested-by: Geoffrey McRae <geoff@xxxxxxxxxxxxxxx>
Reviewed-by: Eduardo Habkost <ehabkost@xxxxxxxxxx>
> ---
> target/i386/cpu.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 6ebbef2..54d908f 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -4830,17 +4830,20 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
>
> qemu_init_vcpu(cs);
>
> - /* Only Intel CPUs support hyperthreading. Even though QEMU fixes this
> - * issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX
> - * based on inputs (sockets,cores,threads), it is still better to gives
> + /* Most Intel and certain AMD CPUs support hyperthreading. Even though QEMU
> + * fixes this issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX
> + * based on inputs (sockets,cores,threads), it is still better to give
> * users a warning.
> *
> * 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) {
> - error_report("AMD CPU doesn't support hyperthreading. Please configure"
> - " -smp options properly.");
> + if (IS_AMD_CPU(env) &&
> + !(env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) &&
> + cs->nr_threads > 1 && !ht_warned) {
> + error_report("This family of AMD CPU doesn't support "
> + "hyperthreading. Please configure -smp "
> + "options properly.");
> ht_warned = true;
> }
>
> --
> 2.7.4
>
>
--
Eduardo
