Re: [PATCH 09/11] perf kvm: use defines of kvm events

[Paolo Bonzini <pbonzini@redhat.com>]

Il 25/04/2014 11:12, Christian Borntraeger ha scritto:
> From: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
>
> Currently perf-kvm uses string literals for kvm event names,
> but it works only for x86, because other architectures may have
> other names for those events.
>
> This patch introduces defines for kvm_entry and kvm_exit events
> and lets perf-kvm replace literals.
>
> Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  arch/x86/include/uapi/asm/kvm.h |  8 ++++++++
>  tools/perf/builtin-kvm.c        | 10 ++++------
>  2 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
> index d3a8778..88c0099 100644
> --- a/arch/x86/include/uapi/asm/kvm.h
> +++ b/arch/x86/include/uapi/asm/kvm.h
> @@ -8,6 +8,8 @@
>
>  #include <linux/types.h>
>  #include <linux/ioctl.h>
> +#include <asm/svm.h>
> +#include <asm/vmx.h>
>
>  #define DE_VECTOR 0
>  #define DB_VECTOR 1
> @@ -342,4 +344,10 @@ struct kvm_xcrs {
>  struct kvm_sync_regs {
>  };
>
> +#define VCPU_ID "vcpu_id"
> +
> +#define KVM_ENTRY "kvm:kvm_entry"
> +#define KVM_EXIT "kvm:kvm_exit"
> +#define KVM_EXIT_REASON "exit_reason"
> +
>  #endif /* _ASM_X86_KVM_H */

What about adding a new asm/kvm-perf.h header instead?

1) I don't like very much the namespace pollution that the first hunk 
causes (and the second one isn't really pretty either).

2) perf doesn't need most of uapi/asm/kvm.h, in fact it only needs a 
couple of #defines because it is a dependency of uapi/asm/svm.h.  So it 
is uapi/asm/svm.h that should include uapi/asm/kvm.h, not perf.

Paolo

> diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
> index 806c0e4..9a162ae 100644
> --- a/tools/perf/builtin-kvm.c
> +++ b/tools/perf/builtin-kvm.c
> @@ -30,8 +30,6 @@
>  #include <math.h>
>
>  #ifdef HAVE_KVM_STAT_SUPPORT
> -#include <asm/svm.h>
> -#include <asm/vmx.h>
>  #include <asm/kvm.h>
>
>  struct event_key {
> @@ -130,12 +128,12 @@ static void exit_event_get_key(struct perf_evsel *evsel,
>  			       struct event_key *key)
>  {
>  	key->info = 0;
> -	key->key = perf_evsel__intval(evsel, sample, "exit_reason");
> +	key->key = perf_evsel__intval(evsel, sample, KVM_EXIT_REASON);
>  }
>
>  static bool kvm_exit_event(struct perf_evsel *evsel)
>  {
> -	return !strcmp(evsel->name, "kvm:kvm_exit");
> +	return !strcmp(evsel->name, KVM_EXIT);
>  }
>
>  static bool exit_event_begin(struct perf_evsel *evsel,
> @@ -151,7 +149,7 @@ static bool exit_event_begin(struct perf_evsel *evsel,
>
>  static bool kvm_entry_event(struct perf_evsel *evsel)
>  {
> -	return !strcmp(evsel->name, "kvm:kvm_entry");
> +	return !strcmp(evsel->name, KVM_ENTRY);
>  }
>
>  static bool exit_event_end(struct perf_evsel *evsel,
> @@ -557,7 +555,7 @@ struct vcpu_event_record *per_vcpu_record(struct thread *thread,
>  			return NULL;
>  		}
>
> -		vcpu_record->vcpu_id = perf_evsel__intval(evsel, sample, "vcpu_id");
> +		vcpu_record->vcpu_id = perf_evsel__intval(evsel, sample, VCPU_ID);
>  		thread->priv = vcpu_record;
>  	}
>
>