Re: [Qemu-devel] [PATCH 1/4] kvm-all: add kvm_ioctl, kvm_vm_ioctl, kvm_vcpu_ioctl tracepoints

[Andreas Färber]

Am 03.05.2013 14:01, schrieb Stefan Hajnoczi:
> From: Kazuya Saito <address@hidden>
> 
> This patch adds tracepoints at ioctl to kvm. Tracing these ioctl is
> useful for clarification whether the cause of troubles is qemu or kvm.
> 
> Signed-off-by: Kazuya Saito <address@hidden>
> Reviewed-by: Paolo Bonzini <address@hidden>
> Signed-off-by: Stefan Hajnoczi <address@hidden>
> ---
>  kvm-all.c    | 4 ++++
>  trace-events | 5 +++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/kvm-all.c b/kvm-all.c
> index f6c0f4a..4f73b98 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -33,6 +33,7 @@
>  #include "exec/memory.h"
>  #include "exec/address-spaces.h"
>  #include "qemu/event_notifier.h"
> +#include "trace.h"
>  
>  /* This check must be after config-host.h is included */
>  #ifdef CONFIG_EVENTFD
> @@ -1687,6 +1688,7 @@ int kvm_ioctl(KVMState *s, int type, ...)
>      arg = va_arg(ap, void *);
>      va_end(ap);
>  
> +    trace_kvm_ioctl(type, arg);
>      ret = ioctl(s->fd, type, arg);
>      if (ret == -1) {
>          ret = -errno;
> @@ -1704,6 +1706,7 @@ int kvm_vm_ioctl(KVMState *s, int type, ...)
>      arg = va_arg(ap, void *);
>      va_end(ap);
>  
> +    trace_kvm_vm_ioctl(type, arg);
>      ret = ioctl(s->vmfd, type, arg);
>      if (ret == -1) {
>          ret = -errno;
> @@ -1721,6 +1724,7 @@ int kvm_vcpu_ioctl(CPUState *cpu, int type, ...)
>      arg = va_arg(ap, void *);
>      va_end(ap);
>  
> +    trace_kvm_vcpu_ioctl(cpu->cpu_index, type, arg);
>      ret = ioctl(cpu->kvm_fd, type, arg);
>      if (ret == -1) {
>          ret = -errno;
> diff --git a/trace-events b/trace-events
> index 55e80be..d5bc7a5 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1153,3 +1153,8 @@ virtio_ccw_new_device(int cssid, int ssid, int schid, 
> int devno, const char *dev
>  
>  # migration.c
>  migrate_set_state(int new_state) "new state %d"
> +
> +# kvm-all.c
> +kvm_ioctl(int type, void *arg) "type %d, arg %p"
> +kvm_vm_ioctl(int type, void *arg) "type %d, arg %p"
> +kvm_vcpu_ioctl(int cpu_index, int type, void *arg) "cpu_index %d, type %d, 
> arg %p"

Sorry that I'm just seeing this patch now (wasn't CC'ed), but I wonder
whether cpu_index is the best thing to trace here? Can we still change
trace event API or would we have to nack/change now?

CC'ing Igor since he just introduced a cpu_get_arch_id() and there's
also a kvm_arch_vcpu_id() introduced earlier by Eduardo.

Regards,
Andreas

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