Re: [PATCH v4 4/9] target/i386/kvm: Save/load MSRs of kvmclock2 (KVM_FEATURE_CLOCKSOURCE2)

["Chen, Zide" <zide.chen@intel.com>]

On 7/16/2024 9:10 AM, Zhao Liu wrote:
> MSR_KVM_SYSTEM_TIME_NEW and MSR_KVM_WALL_CLOCK_NEW are bound to
> kvmclock2 (KVM_FEATURE_CLOCKSOURCE2).
> 
> Add the save/load support for these 2 MSRs just like kvmclock MSRs.
> 
> Signed-off-by: Zhao Liu <zhao1.liu@intel.com>

Reviewed-by: Zide Chen <zide.chen@intel.com>

> ---
>  target/i386/cpu.h     |  2 ++
>  target/i386/kvm/kvm.c | 16 ++++++++++++++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index b59bdc1c9d9d..35dc68631989 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1826,6 +1826,8 @@ typedef struct CPUArchState {
>  
>      uint64_t system_time_msr;
>      uint64_t wall_clock_msr;
> +    uint64_t system_time_new_msr;
> +    uint64_t wall_clock_new_msr;
>      uint64_t steal_time_msr;
>      uint64_t async_pf_en_msr;
>      uint64_t async_pf_int_msr;
> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> index ac434e83b64c..64e54beac7b3 100644
> --- a/target/i386/kvm/kvm.c
> +++ b/target/i386/kvm/kvm.c
> @@ -3423,6 +3423,12 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
>              kvm_msr_entry_add(cpu, MSR_KVM_SYSTEM_TIME, env->system_time_msr);
>              kvm_msr_entry_add(cpu, MSR_KVM_WALL_CLOCK, env->wall_clock_msr);
>          }
> +        if (env->features[FEAT_KVM] & CPUID_KVM_CLOCK2) {
> +            kvm_msr_entry_add(cpu, MSR_KVM_SYSTEM_TIME_NEW,
> +                              env->system_time_new_msr);
> +            kvm_msr_entry_add(cpu, MSR_KVM_WALL_CLOCK_NEW,
> +                              env->wall_clock_new_msr);
> +        }
>          if (env->features[FEAT_KVM] & CPUID_KVM_ASYNCPF_INT) {
>              kvm_msr_entry_add(cpu, MSR_KVM_ASYNC_PF_INT, env->async_pf_int_msr);
>          }
> @@ -3901,6 +3907,10 @@ static int kvm_get_msrs(X86CPU *cpu)
>          kvm_msr_entry_add(cpu, MSR_KVM_SYSTEM_TIME, 0);
>          kvm_msr_entry_add(cpu, MSR_KVM_WALL_CLOCK, 0);
>      }
> +    if (env->features[FEAT_KVM] & CPUID_KVM_CLOCK2) {
> +        kvm_msr_entry_add(cpu, MSR_KVM_SYSTEM_TIME_NEW, 0);
> +        kvm_msr_entry_add(cpu, MSR_KVM_WALL_CLOCK_NEW, 0);
> +    }
>      if (env->features[FEAT_KVM] & CPUID_KVM_ASYNCPF_INT) {
>          kvm_msr_entry_add(cpu, MSR_KVM_ASYNC_PF_INT, 0);
>      }
> @@ -4167,6 +4177,12 @@ static int kvm_get_msrs(X86CPU *cpu)
>          case MSR_KVM_WALL_CLOCK:
>              env->wall_clock_msr = msrs[i].data;
>              break;
> +        case MSR_KVM_SYSTEM_TIME_NEW:
> +            env->system_time_new_msr = msrs[i].data;
> +            break;
> +        case MSR_KVM_WALL_CLOCK_NEW:
> +            env->wall_clock_new_msr = msrs[i].data;
> +            break;
>          case MSR_MCG_STATUS:
>              env->mcg_status = msrs[i].data;
>              break;