Re: [PATCH V2 3/3] target/i386: Move host_cpu_enable_cpu_pm into kvm_cpu_realizefn()

2024-05-31 Thread Chen, Zide 



On 5/30/2024 11:53 PM, Zhao Liu wrote:
> On Fri, May 24, 2024 at 01:00:17PM -0700, Zide Chen wrote:
>> Date: Fri, 24 May 2024 13:00:17 -0700
>> From: Zide Chen 
>> Subject: [PATCH V2 3/3] target/i386: Move host_cpu_enable_cpu_pm into
>>  kvm_cpu_realizefn()
>> X-Mailer: git-send-email 2.34.1
>>
>> It seems not a good idea to expand features in host_cpu_realizefn,
>> which is for host CPU only. 
> 
> It is restricted by max_features and should be part of the "max" CPU,
> and the current target/i386/host-cpu.c should only serve the “host” CPU.

Yes, since this file only serves for "host" CPU, that's why I proposed
to move this code to kvm_cpu_realizefn().

> 
>> Additionally, cpu-pm option is KVM
>> specific, and it's cleaner to put it in kvm_cpu_realizefn(), together
>> with the WAITPKG code.
>>
>> Fixes: f5cc5a5c1686 ("i386: split cpu accelerators from cpu.c, using 
>> AccelCPUClass")
>> Signed-off-by: Zide Chen 
>> ---
>>  target/i386/host-cpu.c| 12 
>>  target/i386/kvm/kvm-cpu.c | 11 +--
>>  2 files changed, 9 insertions(+), 14 deletions(-)
>>
>> diff --git a/target/i386/host-cpu.c b/target/i386/host-cpu.c
>> index 280e427c017c..8b8bf5afeccf 100644
>> --- a/target/i386/host-cpu.c
>> +++ b/target/i386/host-cpu.c
>> @@ -42,15 +42,6 @@ static uint32_t host_cpu_phys_bits(void)
>>  return host_phys_bits;
>>  }
>>  
>> -static void host_cpu_enable_cpu_pm(X86CPU *cpu)
>> -{
>> -CPUX86State *env = >env;
>> -
>> -host_cpuid(5, 0, >mwait.eax, >mwait.ebx,
>> -   >mwait.ecx, >mwait.edx);
>> -env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
>> -}
>> -
>>  static uint32_t host_cpu_adjust_phys_bits(X86CPU *cpu)
>>  {
>>  uint32_t host_phys_bits = host_cpu_phys_bits();
>> @@ -83,9 +74,6 @@ bool host_cpu_realizefn(CPUState *cs, Error **errp)
>>  X86CPU *cpu = X86_CPU(cs);
>>  CPUX86State *env = >env;
>>  
>> -if (cpu->max_features && enable_cpu_pm) {
>> -host_cpu_enable_cpu_pm(cpu);
>> -}
>>  if (env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) {
>>  uint32_t phys_bits = host_cpu_adjust_phys_bits(cpu);
>>  
>> diff --git a/target/i386/kvm/kvm-cpu.c b/target/i386/kvm/kvm-cpu.c
>> index 3adcedf0dbc3..197c892da89a 100644
>> --- a/target/i386/kvm/kvm-cpu.c
>> +++ b/target/i386/kvm/kvm-cpu.c
>> @@ -64,9 +64,16 @@ static bool kvm_cpu_realizefn(CPUState *cs, Error **errp)
>>   *   cpu_common_realizefn() (via xcc->parent_realize)
>>   */
>>  if (cpu->max_features) {
>> -if (enable_cpu_pm && kvm_has_waitpkg()) {
>> -env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG;
>> +if (enable_cpu_pm) {
>> +if (kvm_has_waitpkg()) {
>> +env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG;
>> +}
> 
> If you agree with my comment in patch 2, here we need a mwait bit check.

I still think that take advantaged of x86_cpu_filter_features() to check
host availability is a better choice.

> 
>> +host_cpuid(5, 0, >mwait.eax, >mwait.ebx,
>> +   >mwait.ecx, >mwait.edx);
>> +env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
>>  }
>> +
>>  if (cpu->ucode_rev == 0) {
>>  cpu->ucode_rev =
>>  kvm_arch_get_supported_msr_feature(kvm_state,
>> -- 
>> 2.34.1
>>
>>

Re: [PATCH V2 3/3] target/i386: Move host_cpu_enable_cpu_pm into kvm_cpu_realizefn()

2024-05-31 Thread Zhao Liu 
On Fri, May 24, 2024 at 01:00:17PM -0700, Zide Chen wrote:
> Date: Fri, 24 May 2024 13:00:17 -0700
> From: Zide Chen 
> Subject: [PATCH V2 3/3] target/i386: Move host_cpu_enable_cpu_pm into
>  kvm_cpu_realizefn()
> X-Mailer: git-send-email 2.34.1
> 
> It seems not a good idea to expand features in host_cpu_realizefn,
> which is for host CPU only. 

It is restricted by max_features and should be part of the "max" CPU,
and the current target/i386/host-cpu.c should only serve the “host” CPU.

> Additionally, cpu-pm option is KVM
> specific, and it's cleaner to put it in kvm_cpu_realizefn(), together
> with the WAITPKG code.
> 
> Fixes: f5cc5a5c1686 ("i386: split cpu accelerators from cpu.c, using 
> AccelCPUClass")
> Signed-off-by: Zide Chen 
> ---
>  target/i386/host-cpu.c| 12 
>  target/i386/kvm/kvm-cpu.c | 11 +--
>  2 files changed, 9 insertions(+), 14 deletions(-)
> 
> diff --git a/target/i386/host-cpu.c b/target/i386/host-cpu.c
> index 280e427c017c..8b8bf5afeccf 100644
> --- a/target/i386/host-cpu.c
> +++ b/target/i386/host-cpu.c
> @@ -42,15 +42,6 @@ static uint32_t host_cpu_phys_bits(void)
>  return host_phys_bits;
>  }
>  
> -static void host_cpu_enable_cpu_pm(X86CPU *cpu)
> -{
> -CPUX86State *env = >env;
> -
> -host_cpuid(5, 0, >mwait.eax, >mwait.ebx,
> -   >mwait.ecx, >mwait.edx);
> -env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
> -}
> -
>  static uint32_t host_cpu_adjust_phys_bits(X86CPU *cpu)
>  {
>  uint32_t host_phys_bits = host_cpu_phys_bits();
> @@ -83,9 +74,6 @@ bool host_cpu_realizefn(CPUState *cs, Error **errp)
>  X86CPU *cpu = X86_CPU(cs);
>  CPUX86State *env = >env;
>  
> -if (cpu->max_features && enable_cpu_pm) {
> -host_cpu_enable_cpu_pm(cpu);
> -}
>  if (env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) {
>  uint32_t phys_bits = host_cpu_adjust_phys_bits(cpu);
>  
> diff --git a/target/i386/kvm/kvm-cpu.c b/target/i386/kvm/kvm-cpu.c
> index 3adcedf0dbc3..197c892da89a 100644
> --- a/target/i386/kvm/kvm-cpu.c
> +++ b/target/i386/kvm/kvm-cpu.c
> @@ -64,9 +64,16 @@ static bool kvm_cpu_realizefn(CPUState *cs, Error **errp)
>   *   cpu_common_realizefn() (via xcc->parent_realize)
>   */
>  if (cpu->max_features) {
> -if (enable_cpu_pm && kvm_has_waitpkg()) {
> -env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG;
> +if (enable_cpu_pm) {
> +if (kvm_has_waitpkg()) {
> +env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG;
> +}

If you agree with my comment in patch 2, here we need a mwait bit check.

> +host_cpuid(5, 0, >mwait.eax, >mwait.ebx,
> +   >mwait.ecx, >mwait.edx);
> +env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
>  }
> +
>  if (cpu->ucode_rev == 0) {
>  cpu->ucode_rev =
>  kvm_arch_get_supported_msr_feature(kvm_state,
> -- 
> 2.34.1
> 
>

[PATCH V2 3/3] target/i386: Move host_cpu_enable_cpu_pm into kvm_cpu_realizefn()

2024-05-24 Thread Zide Chen 
It seems not a good idea to expand features in host_cpu_realizefn,
which is for host CPU only.  Additionally, cpu-pm option is KVM
specific, and it's cleaner to put it in kvm_cpu_realizefn(), together
with the WAITPKG code.

Fixes: f5cc5a5c1686 ("i386: split cpu accelerators from cpu.c, using 
AccelCPUClass")
Signed-off-by: Zide Chen 
---
 target/i386/host-cpu.c| 12 
 target/i386/kvm/kvm-cpu.c | 11 +--
 2 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/target/i386/host-cpu.c b/target/i386/host-cpu.c
index 280e427c017c..8b8bf5afeccf 100644
--- a/target/i386/host-cpu.c
+++ b/target/i386/host-cpu.c
@@ -42,15 +42,6 @@ static uint32_t host_cpu_phys_bits(void)
 return host_phys_bits;
 }
 
-static void host_cpu_enable_cpu_pm(X86CPU *cpu)
-{
-CPUX86State *env = >env;
-
-host_cpuid(5, 0, >mwait.eax, >mwait.ebx,
-   >mwait.ecx, >mwait.edx);
-env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
-}
-
 static uint32_t host_cpu_adjust_phys_bits(X86CPU *cpu)
 {
 uint32_t host_phys_bits = host_cpu_phys_bits();
@@ -83,9 +74,6 @@ bool host_cpu_realizefn(CPUState *cs, Error **errp)
 X86CPU *cpu = X86_CPU(cs);
 CPUX86State *env = >env;
 
-if (cpu->max_features && enable_cpu_pm) {
-host_cpu_enable_cpu_pm(cpu);
-}
 if (env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) {
 uint32_t phys_bits = host_cpu_adjust_phys_bits(cpu);
 
diff --git a/target/i386/kvm/kvm-cpu.c b/target/i386/kvm/kvm-cpu.c
index 3adcedf0dbc3..197c892da89a 100644
--- a/target/i386/kvm/kvm-cpu.c
+++ b/target/i386/kvm/kvm-cpu.c
@@ -64,9 +64,16 @@ static bool kvm_cpu_realizefn(CPUState *cs, Error **errp)
  *   cpu_common_realizefn() (via xcc->parent_realize)
  */
 if (cpu->max_features) {
-if (enable_cpu_pm && kvm_has_waitpkg()) {
-env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG;
+if (enable_cpu_pm) {
+if (kvm_has_waitpkg()) {
+env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG;
+}
+
+host_cpuid(5, 0, >mwait.eax, >mwait.ebx,
+   >mwait.ecx, >mwait.edx);
+env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
 }
+
 if (cpu->ucode_rev == 0) {
 cpu->ucode_rev =
 kvm_arch_get_supported_msr_feature(kvm_state,
-- 
2.34.1