Re: [Qemu-devel] [PATCH V2] i386: extended the cpuid_level when Intel PT is enabled

[Paolo Bonzini]

On 30/01/19 00:52, Luwei Kang wrote:
> Intel Processor Trace required CPUID[0x14] but the cpuid_level
> have no change when create a kvm guest with
> e.g. "-cpu qemu64,+intel-pt".
> 
> Signed-off-by: Eduardo Habkost <address@hidden>
> Signed-off-by: Luwei Kang <address@hidden>
> ---
>  hw/i386/pc.c      | 1 +
>  target/i386/cpu.c | 9 +++++++++
>  target/i386/cpu.h | 3 +++
>  3 files changed, 13 insertions(+)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 73d688f..72a0a70 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -122,6 +122,7 @@ GlobalProperty pc_compat_3_1[] = {
>      { "Cascadelake-Server" "-" TYPE_X86_CPU,  "mpx", "on" },
>      { "Icelake-Client" "-" TYPE_X86_CPU,      "mpx", "on" },
>      { "Icelake-Server" "-" TYPE_X86_CPU,      "mpx", "on" },
> +    { TYPE_X86_CPU, "x-intel-pt-auto-level", "off" },
>  };
>  const size_t pc_compat_3_1_len = G_N_ELEMENTS(pc_compat_3_1);
>  
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 2f54125..6dddd99 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -5023,6 +5023,13 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error 
> **errp)
>          x86_cpu_adjust_feat_level(cpu, FEAT_C000_0001_EDX);
>          x86_cpu_adjust_feat_level(cpu, FEAT_SVM);
>          x86_cpu_adjust_feat_level(cpu, FEAT_XSAVE);
> +
> +        /* Intel Processor Trace requires CPUID[0x14] */
> +        if ((env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_INTEL_PT) &&
> +             kvm_enabled() && cpu->intel_pt_auto_level) {
> +            x86_cpu_adjust_level(cpu, &cpu->env.cpuid_min_level, 0x14);
> +        }
> +
>          /* SVM requires CPUID[0x8000000A] */
>          if (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_SVM) {
>              x86_cpu_adjust_level(cpu, &env->cpuid_min_xlevel, 0x8000000A);
> @@ -5816,6 +5823,8 @@ static Property x86_cpu_properties[] = {
>      DEFINE_PROP_INT32("x-hv-max-vps", X86CPU, hv_max_vps, -1),
>      DEFINE_PROP_BOOL("x-hv-synic-kvm-only", X86CPU, hyperv_synic_kvm_only,
>                       false),
> +    DEFINE_PROP_BOOL("x-intel-pt-auto-level", X86CPU, intel_pt_auto_level,
> +                     true),
>      DEFINE_PROP_END_OF_LIST()
>  };
>  
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 59656a7..090baa4 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1455,6 +1455,9 @@ struct X86CPU {
>      /* Enable auto level-increase for all CPUID leaves */
>      bool full_cpuid_auto_level;
>  
> +    /* Enable auto level-increase for Intel Processor Trace leave */
> +    bool intel_pt_auto_level;
> +
>      /* if true fill the top bits of the MTRR_PHYSMASKn variable range */
>      bool fill_mtrr_mask;
>  
> 

Eduardo is back, but I've queued this anyway.

Thanks,

Paolo