Re: [Qemu-devel] [PATCH v2 3/4] i386/kvm: introduce tsc_is_stable_and_known()

[David Hildenbrand]

On 07.08.2017 10:57, Ladi Prosek wrote:
> Move the "is TSC stable and known" condition to a reusable helper.
> 
> Signed-off-by: Ladi Prosek 
> ---
>  target/i386/kvm.c | 13 ++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index 15d56ae..2dc01c9 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -611,6 +611,15 @@ static int kvm_arch_set_tsc_khz(CPUState *cs)
>  return 0;
>  }
>  
> +static bool tsc_is_stable_and_known(CPUX86State *env)
> +{
> +if (!env->tsc_khz) {
> +return false;
> +}
> +return (env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC)
> +|| env->user_tsc_khz;
> +}> +
>  static int hyperv_handle_properties(CPUState *cs)
>  {
>  X86CPU *cpu = X86_CPU(cs);
> @@ -986,9 +995,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
>  && cpu->expose_kvm
>  && kvm_base == KVM_CPUID_SIGNATURE
>  /* TSC clock must be stable and known for this feature. */
> -&& ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC)
> -|| env->user_tsc_khz != 0)
> -&& env->tsc_khz != 0) {
> +&& tsc_is_stable_and_known(env)) {
>  
>  c = _data.entries[cpuid_i++];
>  c->function = KVM_CPUID_SIGNATURE | 0x10;
> 

Reviewed-by: David Hildenbrand 

-- 

Thanks,

David

[Qemu-devel] [PATCH v2 3/4] i386/kvm: introduce tsc_is_stable_and_known()

[Ladi Prosek]

Move the "is TSC stable and known" condition to a reusable helper.

Signed-off-by: Ladi Prosek 
---
 target/i386/kvm.c | 13 ++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 15d56ae..2dc01c9 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -611,6 +611,15 @@ static int kvm_arch_set_tsc_khz(CPUState *cs)
 return 0;
 }
 
+static bool tsc_is_stable_and_known(CPUX86State *env)
+{
+if (!env->tsc_khz) {
+return false;
+}
+return (env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC)
+|| env->user_tsc_khz;
+}
+
 static int hyperv_handle_properties(CPUState *cs)
 {
 X86CPU *cpu = X86_CPU(cs);
@@ -986,9 +995,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
 && cpu->expose_kvm
 && kvm_base == KVM_CPUID_SIGNATURE
 /* TSC clock must be stable and known for this feature. */
-&& ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC)
-|| env->user_tsc_khz != 0)
-&& env->tsc_khz != 0) {
+&& tsc_is_stable_and_known(env)) {
 
 c = _data.entries[cpuid_i++];
 c->function = KVM_CPUID_SIGNATURE | 0x10;
-- 
2.9.3