| Message ID | 20160914141949.27402-9-robert@sixbynine.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 14 September 2016 at 15:19, Robert Bragg <robert@sixbynine.org> wrote: > Consistent with the kernel.perf_event_paranoid sysctl option that can > allow non-root users to access system wide cpu metrics, this can > optionally allow non-root users to access system wide OA counter metrics > from Gen graphics hardware. > > Signed-off-by: Robert Bragg <robert@sixbynine.org> > --- > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_perf.c | 45 +++++++++++++++++++++++++++++++++++++++- > 2 files changed, 45 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index f5ddf70..eaba7a9 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -2142,6 +2142,7 @@ struct drm_i915_private { > bool initialized; > > struct kobject *metrics_kobj; > + struct ctl_table_header *sysctl_header; > > struct mutex lock; > struct list_head streams; > diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c > index e890c38..38b13fa 100644 > --- a/drivers/gpu/drm/i915/i915_perf.c > +++ b/drivers/gpu/drm/i915/i915_perf.c > @@ -62,6 +62,8 @@ > #define POLL_FREQUENCY 200 > #define POLL_PERIOD (NSEC_PER_SEC / POLL_FREQUENCY) > > +static u32 i915_perf_stream_paranoid = true; > + > /* The maximum exponent the hardware accepts is 63 (essentially it selects one > * of the 64bit timestamp bits to trigger reports from) but there's currently > * no known use case for sampling as infrequently as once per 47 thousand years. > @@ -1170,7 +1172,13 @@ int i915_perf_open_ioctl_locked(struct drm_device *dev, > } > } > > - if (!specific_ctx && !capable(CAP_SYS_ADMIN)) { > + /* Similar to perf's kernel.perf_paranoid_cpu sysctl option > + * we check a dev.i915.perf_stream_paranoid sysctl option > + * to determine if it's ok to access system wide OA counters > + * without CAP_SYS_ADMIN privileges. > + */ > + if (!specific_ctx && > + i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) { > DRM_ERROR("Insufficient privileges to open system-wide i915 perf stream\n"); > ret = -EACCES; > goto err_ctx; > @@ -1417,6 +1425,37 @@ void i915_perf_unregister(struct drm_i915_private *dev_priv) > dev_priv->perf.metrics_kobj = NULL; > } > > +static struct ctl_table oa_table[] = { > + { > + .procname = "perf_stream_paranoid", > + .data = &i915_perf_stream_paranoid, > + .maxlen = sizeof(i915_perf_stream_paranoid), > + .mode = 0644, > + .proc_handler = proc_dointvec, If this really is just a bool, why not: .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one Reviewed-by: Matthew Auld <matthew.auld@intel.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index f5ddf70..eaba7a9 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2142,6 +2142,7 @@ struct drm_i915_private { bool initialized; struct kobject *metrics_kobj; + struct ctl_table_header *sysctl_header; struct mutex lock; struct list_head streams; diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index e890c38..38b13fa 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -62,6 +62,8 @@ #define POLL_FREQUENCY 200 #define POLL_PERIOD (NSEC_PER_SEC / POLL_FREQUENCY) +static u32 i915_perf_stream_paranoid = true; + /* The maximum exponent the hardware accepts is 63 (essentially it selects one * of the 64bit timestamp bits to trigger reports from) but there's currently * no known use case for sampling as infrequently as once per 47 thousand years. @@ -1170,7 +1172,13 @@ int i915_perf_open_ioctl_locked(struct drm_device *dev, } } - if (!specific_ctx && !capable(CAP_SYS_ADMIN)) { + /* Similar to perf's kernel.perf_paranoid_cpu sysctl option + * we check a dev.i915.perf_stream_paranoid sysctl option + * to determine if it's ok to access system wide OA counters + * without CAP_SYS_ADMIN privileges. + */ + if (!specific_ctx && + i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) { DRM_ERROR("Insufficient privileges to open system-wide i915 perf stream\n"); ret = -EACCES; goto err_ctx; @@ -1417,6 +1425,37 @@ void i915_perf_unregister(struct drm_i915_private *dev_priv) dev_priv->perf.metrics_kobj = NULL; } +static struct ctl_table oa_table[] = { + { + .procname = "perf_stream_paranoid", + .data = &i915_perf_stream_paranoid, + .maxlen = sizeof(i915_perf_stream_paranoid), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + {} +}; + +static struct ctl_table i915_root[] = { + { + .procname = "i915", + .maxlen = 0, + .mode = 0555, + .child = oa_table, + }, + {} +}; + +static struct ctl_table dev_root[] = { + { + .procname = "dev", + .maxlen = 0, + .mode = 0555, + .child = i915_root, + }, + {} +}; + void i915_perf_init(struct drm_i915_private *dev_priv) { if (!IS_HASWELL(dev_priv)) @@ -1449,6 +1488,8 @@ void i915_perf_init(struct drm_i915_private *dev_priv) dev_priv->perf.oa.n_builtin_sets = i915_oa_n_builtin_metric_sets_hsw; + dev_priv->perf.sysctl_header = register_sysctl_table(dev_root); + dev_priv->perf.initialized = true; } @@ -1457,6 +1498,8 @@ void i915_perf_fini(struct drm_i915_private *dev_priv) if (!dev_priv->perf.initialized) return; + unregister_sysctl_table(dev_priv->perf.sysctl_header); + memset(&dev_priv->perf.oa.ops, 0, sizeof(dev_priv->perf.oa.ops)); dev_priv->perf.initialized = false; }
Consistent with the kernel.perf_event_paranoid sysctl option that can allow non-root users to access system wide cpu metrics, this can optionally allow non-root users to access system wide OA counter metrics from Gen graphics hardware. Signed-off-by: Robert Bragg <robert@sixbynine.org> --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_perf.c | 45 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 45 insertions(+), 1 deletion(-)