Re: [PATCH RFC 06/22] i386: move hyperv_limits initialization to x86_cpu_realizefn()

[Eduardo Habkost]

On Fri, Sep 04, 2020 at 04:54:15PM +0200, Vitaly Kuznetsov wrote:
> As a preparation to expanding Hyper-V CPU features early, move
> hyperv_limits initialization to x86_cpu_realizefn().
> 
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  target/i386/cpu.c |  5 +++++
>  target/i386/cpu.h |  1 +
>  target/i386/kvm.c | 13 ++++++++++++-
>  3 files changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index e605399eb8c0..ef3c672cf415 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -6648,6 +6648,11 @@ static void x86_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      cpu->hyperv_version_id[0] = 0x00001bbc;
>      cpu->hyperv_version_id[1] = 0x00060001;
>  
> +    /* Hypervisor implementation limits */
> +    cpu->hyperv_limits[0] = 64;
> +    cpu->hyperv_limits[1] = 0;
> +    cpu->hyperv_limits[2] = 0;
> +
>      if (cpu->ucode_rev == 0) {
>          /* The default is the same as KVM's.  */
>          if (IS_AMD_CPU(env)) {
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 2630ffd2d4b2..095d0bf75493 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1662,6 +1662,7 @@ struct X86CPU {
>      uint32_t hyperv_vendor_id[3];
>      uint32_t hyperv_interface_id[4];
>      uint32_t hyperv_version_id[4];
> +    uint32_t hyperv_limits[3];
>  
>      bool check_cpuid;
>      bool enforce_cpuid;
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index 169bae2779a4..720c30e9df17 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -1253,6 +1253,15 @@ static int hyperv_handle_properties(CPUState *cs,
>              env->features[FEAT_HYPERV_EBX] = c->ebx;
>              env->features[FEAT_HYPERV_EDX] = c->eax;
>          }
> +
> +        c = cpuid_find_entry(cpuid, HV_CPUID_IMPLEMENT_LIMITS, 0);
> +        if (c) {
> +            cpu->hv_max_vps = c->eax;
> +            cpu->hyperv_limits[0] = c->ebx;
> +            cpu->hyperv_limits[1] = c->ecx;
> +            cpu->hyperv_limits[2] = c->edx;
> +        }
> +

Sam question I had for vendor id and version id: should it go to
a separate patch as it changes behavior of hv-passthrough?

>          c = cpuid_find_entry(cpuid, HV_CPUID_ENLIGHTMENT_INFO, 0);
>          if (c) {
>              env->features[FEAT_HV_RECOMM_EAX] = c->eax;
> @@ -1355,7 +1364,9 @@ static int hyperv_handle_properties(CPUState *cs,
>      c = &cpuid_ent[cpuid_i++];
>      c->function = HV_CPUID_IMPLEMENT_LIMITS;
>      c->eax = cpu->hv_max_vps;
> -    c->ebx = 0x40;
> +    c->ebx = cpu->hyperv_limits[0];
> +    c->ecx = cpu->hyperv_limits[1];
> +    c->edx = cpu->hyperv_limits[2];
>  
>      if (hyperv_feat_enabled(cpu, HYPERV_FEAT_EVMCS)) {
>          __u32 function;
> -- 
> 2.25.4
> 

-- 
Eduardo