Re: [PATCH V7 11/18] KVM: x86/pmu: Add IA32_DS_AREA MSR emulation to support guest DS

[Peter Zijlstra]

On Tue, Jun 22, 2021 at 05:42:59PM +0800, Zhu Lingshan wrote:
> diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
> index 190d8d98abf0..b336bcaad626 100644
> --- a/arch/x86/events/intel/core.c
> +++ b/arch/x86/events/intel/core.c
> @@ -21,6 +21,7 @@
>  #include <asm/intel_pt.h>
>  #include <asm/apic.h>
>  #include <asm/cpu_device_id.h>
> +#include <asm/kvm_host.h>
>  
>  #include "../perf_event.h"
>  
> @@ -3915,6 +3916,7 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
>  {
>  	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
>  	struct perf_guest_switch_msr *arr = cpuc->guest_switch_msrs;
> +	struct kvm_pmu *pmu = (struct kvm_pmu *)data;
>  	u64 intel_ctrl = hybrid(cpuc->pmu, intel_ctrl);
>  	u64 pebs_mask = cpuc->pebs_enabled & x86_pmu.pebs_capable;
>  
> @@ -3945,9 +3947,15 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
>  		return arr;
>  	}
>  
> -	if (!x86_pmu.pebs_vmx)
> +	if (!pmu || !x86_pmu.pebs_vmx)
>  		return arr;
>  
> +	arr[(*nr)++] = (struct perf_guest_switch_msr){
> +		.msr = MSR_IA32_DS_AREA,
> +		.host = (unsigned long)cpuc->ds,
> +		.guest = pmu->ds_area,
> +	};
> +
>  	arr[*nr] = (struct perf_guest_switch_msr){
>  		.msr = MSR_IA32_PEBS_ENABLE,
>  		.host = cpuc->pebs_enabled & ~cpuc->intel_ctrl_guest_mask,

s/pmu/kvm_pmu/ or something. pmu is normally a struct pmu *, and having
it be kvm_pmu here is super confusing.