Re: [PATCH 02/17] drm/xe/perf/uapi: Add perf_stream_paranoid sysctl

[Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>]

On Thu, Dec 07, 2023 at 10:43:14PM -0800, Ashutosh Dixit wrote:
>Normally only superuser/root can access perf counter data. However,
>superuser can set perf_stream_paranoid sysctl to 0 to allow non-privileged
>users to also access perf data. perf_stream_paranoid is introduced at the
>perf layer to allow different perf stream types to share this access
>mechanism.
>
>Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>

lgtm,

Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>

>---
> drivers/gpu/drm/xe/xe_module.c |  5 +++++
> drivers/gpu/drm/xe/xe_perf.c   | 28 ++++++++++++++++++++++++++++
> drivers/gpu/drm/xe/xe_perf.h   |  4 ++++
> 3 files changed, 37 insertions(+)
>
>diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
>index 51bf69b7ab222..8629330d928b0 100644
>--- a/drivers/gpu/drm/xe/xe_module.c
>+++ b/drivers/gpu/drm/xe/xe_module.c
>@@ -11,6 +11,7 @@
> #include "xe_drv.h"
> #include "xe_hw_fence.h"
> #include "xe_pci.h"
>+#include "xe_perf.h"
> #include "xe_pmu.h"
> #include "xe_sched_job.h"
>
>@@ -71,6 +72,10 @@ static const struct init_funcs init_funcs[] = {
> 		.init = xe_register_pci_driver,
> 		.exit = xe_unregister_pci_driver,
> 	},
>+	{
>+		.init = xe_perf_sysctl_register,
>+		.exit = xe_perf_sysctl_unregister,
>+	},
> };
>
> static int __init xe_init(void)
>diff --git a/drivers/gpu/drm/xe/xe_perf.c b/drivers/gpu/drm/xe/xe_perf.c
>index a130076b59aa2..37538e98dcc04 100644
>--- a/drivers/gpu/drm/xe/xe_perf.c
>+++ b/drivers/gpu/drm/xe/xe_perf.c
>@@ -4,9 +4,13 @@
>  */
>
> #include <linux/errno.h>
>+#include <linux/sysctl.h>
>
> #include "xe_perf.h"
>
>+u32 xe_perf_stream_paranoid = true;
>+static struct ctl_table_header *sysctl_header;
>+
> int xe_perf_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
> {
> 	struct drm_xe_perf_param *arg = data;
>@@ -19,3 +23,27 @@ int xe_perf_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
> 		return -EINVAL;
> 	}
> }
>+
>+static struct ctl_table perf_ctl_table[] = {
>+	{
>+	 .procname = "perf_stream_paranoid",
>+	 .data = &xe_perf_stream_paranoid,
>+	 .maxlen = sizeof(xe_perf_stream_paranoid),
>+	 .mode = 0644,
>+	 .proc_handler = proc_dointvec_minmax,
>+	 .extra1 = SYSCTL_ZERO,
>+	 .extra2 = SYSCTL_ONE,
>+	 },
>+	{}
>+};
>+
>+int xe_perf_sysctl_register(void)
>+{
>+	sysctl_header = register_sysctl("dev/xe", perf_ctl_table);
>+	return 0;
>+}
>+
>+void xe_perf_sysctl_unregister(void)
>+{
>+	unregister_sysctl_table(sysctl_header);
>+}
>diff --git a/drivers/gpu/drm/xe/xe_perf.h b/drivers/gpu/drm/xe/xe_perf.h
>index 254cc7cf49fef..1ff0a07ebab30 100644
>--- a/drivers/gpu/drm/xe/xe_perf.h
>+++ b/drivers/gpu/drm/xe/xe_perf.h
>@@ -11,6 +11,10 @@
> struct drm_device;
> struct drm_file;
>
>+extern u32 xe_perf_stream_paranoid;
>+
> int xe_perf_ioctl(struct drm_device *dev, void *data, struct drm_file *file);
>+int xe_perf_sysctl_register(void);
>+void xe_perf_sysctl_unregister(void);
>
> #endif
>-- 
>2.41.0
>