Re: [Intel-gfx] [PATCH i-g-t] intel_gpu_top: Improve error message when insufficient privilege

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Tue, 01 Feb 2022 07:19:46 -0800, Tvrtko Ursulin wrote:
>
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> Print out end user friendly help text when the running user has
> insufficient privilege for accessing system wide performance counters.

Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>

> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Issue: https://gitlab.freedesktop.org/drm/intel/-/issues/5018
> ---
>  tools/intel_gpu_top.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
> index 81c724d1fe1c..0404a5881b40 100644
> --- a/tools/intel_gpu_top.c
> +++ b/tools/intel_gpu_top.c
> @@ -1761,6 +1761,15 @@ int main(int argc, char **argv)
>	if (ret) {
>		fprintf(stderr,
>			"Failed to initialize PMU! (%s)\n", strerror(errno));
> +		if (errno == EACCES && geteuid())
> +			fprintf(stderr,
> +"\n"
> +"When running as a normal user CAP_PERFMON is required to access performance\n"
> +"monitoring. See \"man 7 capabilities\", \"man 8 setcap\", or contact your\n"
> +"distribution vendor for assistance.\n"
> +"\n"
> +"More information can be found at 'Perf events and tool security' document:\n"
> +"https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html\n");
>		ret = EXIT_FAILURE;
>		goto err;
>	}
> --
> 2.32.0
>