diff mbox series

[v3] drm/v3d: Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL

Message ID 20241117214110.162547-1-christian.gmeiner@gmail.com (mailing list archive)
State New
Headers show
Series [v3] drm/v3d: Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL | expand

Commit Message

Christian Gmeiner Nov. 17, 2024, 9:41 p.m. UTC
From: Christian Gmeiner <cgmeiner@igalia.com>

Add a new ioctl, DRM_IOCTL_V3D_PERFMON_SET_GLOBAL, to allow
configuration of a global performance monitor (perfmon).
Use the global perfmon for all jobs to ensure consistent
performance tracking across submissions. This feature is
needed to implement a Perfetto datasources in user-space.

Signed-off-by: Christian Gmeiner <cgmeiner@igalia.com>
---
Changes in v3:
- Reworked commit message.
- Refined some code comments.
- Added missing v3d_perfmon_stop(..) call to v3d_perfmon_destroy_ioctl(..).

Changes in v2:
- Reworked commit message.
- Removed num_perfmon counter for tracking perfmon allocations.
- Allowing allocation of perfmons when the global perfmon is active.
- Return -EAGAIN for submissions with a per job perfmon if the global perfmon is active.
---

---
 drivers/gpu/drm/v3d/v3d_drv.c     |  1 +
 drivers/gpu/drm/v3d/v3d_drv.h     |  8 ++++++
 drivers/gpu/drm/v3d/v3d_perfmon.c | 42 +++++++++++++++++++++++++++++++
 drivers/gpu/drm/v3d/v3d_sched.c   | 14 ++++++++---
 drivers/gpu/drm/v3d/v3d_submit.c  | 10 ++++++++
 include/uapi/drm/v3d_drm.h        | 15 +++++++++++
 6 files changed, 87 insertions(+), 3 deletions(-)

Comments

Maíra Canal Nov. 18, 2024, 11:29 a.m. UTC | #1
Hi Christian,

The patch overall LGTM, I just have one small nit.

On 17/11/24 18:41, Christian Gmeiner wrote:
> From: Christian Gmeiner <cgmeiner@igalia.com>
> 
> Add a new ioctl, DRM_IOCTL_V3D_PERFMON_SET_GLOBAL, to allow
> configuration of a global performance monitor (perfmon).
> Use the global perfmon for all jobs to ensure consistent
> performance tracking across submissions. This feature is
> needed to implement a Perfetto datasources in user-space.
> 
> Signed-off-by: Christian Gmeiner <cgmeiner@igalia.com>
> ---
> Changes in v3:
> - Reworked commit message.
> - Refined some code comments.
> - Added missing v3d_perfmon_stop(..) call to v3d_perfmon_destroy_ioctl(..).
> 
> Changes in v2:
> - Reworked commit message.
> - Removed num_perfmon counter for tracking perfmon allocations.
> - Allowing allocation of perfmons when the global perfmon is active.
> - Return -EAGAIN for submissions with a per job perfmon if the global perfmon is active.
> ---
> 
> ---
>   drivers/gpu/drm/v3d/v3d_drv.c     |  1 +
>   drivers/gpu/drm/v3d/v3d_drv.h     |  8 ++++++
>   drivers/gpu/drm/v3d/v3d_perfmon.c | 42 +++++++++++++++++++++++++++++++
>   drivers/gpu/drm/v3d/v3d_sched.c   | 14 ++++++++---
>   drivers/gpu/drm/v3d/v3d_submit.c  | 10 ++++++++
>   include/uapi/drm/v3d_drm.h        | 15 +++++++++++
>   6 files changed, 87 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
> index d7ff1f5fa481..3c89f0daa5b8 100644
> --- a/drivers/gpu/drm/v3d/v3d_drv.c
> +++ b/drivers/gpu/drm/v3d/v3d_drv.c
> @@ -214,6 +214,7 @@ static const struct drm_ioctl_desc v3d_drm_ioctls[] = {
>   	DRM_IOCTL_DEF_DRV(V3D_PERFMON_GET_VALUES, v3d_perfmon_get_values_ioctl, DRM_RENDER_ALLOW),
>   	DRM_IOCTL_DEF_DRV(V3D_SUBMIT_CPU, v3d_submit_cpu_ioctl, DRM_RENDER_ALLOW | DRM_AUTH),
>   	DRM_IOCTL_DEF_DRV(V3D_PERFMON_GET_COUNTER, v3d_perfmon_get_counter_ioctl, DRM_RENDER_ALLOW),
> +	DRM_IOCTL_DEF_DRV(V3D_PERFMON_SET_GLOBAL, v3d_perfmon_set_global_ioctl, DRM_RENDER_ALLOW),
>   };
>   
>   static const struct drm_driver v3d_drm_driver = {
> diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
> index cf4b23369dc4..a0d920ec2b1d 100644
> --- a/drivers/gpu/drm/v3d/v3d_drv.h
> +++ b/drivers/gpu/drm/v3d/v3d_drv.h
> @@ -179,6 +179,12 @@ struct v3d_dev {
>   		u32 num_allocated;
>   		u32 pages_allocated;
>   	} bo_stats;
> +
> +	/* To support a performance analysis tool in user space, we require
> +	 * a single, globally configured performance monitor (perfmon) for
> +	 * all jobs.
> +	 */
> +	struct v3d_perfmon *global_perfmon;
>   };
>   
>   static inline struct v3d_dev *
> @@ -584,6 +590,8 @@ int v3d_perfmon_get_values_ioctl(struct drm_device *dev, void *data,
>   				 struct drm_file *file_priv);
>   int v3d_perfmon_get_counter_ioctl(struct drm_device *dev, void *data,
>   				  struct drm_file *file_priv);
> +int v3d_perfmon_set_global_ioctl(struct drm_device *dev, void *data,
> +				 struct drm_file *file_priv);
>   
>   /* v3d_sysfs.c */
>   int v3d_sysfs_init(struct device *dev);
> diff --git a/drivers/gpu/drm/v3d/v3d_perfmon.c b/drivers/gpu/drm/v3d/v3d_perfmon.c
> index 156be13ab2ef..df72171d8c80 100644
> --- a/drivers/gpu/drm/v3d/v3d_perfmon.c
> +++ b/drivers/gpu/drm/v3d/v3d_perfmon.c
> @@ -312,6 +312,9 @@ static int v3d_perfmon_idr_del(int id, void *elem, void *data)
>   	if (perfmon == v3d->active_perfmon)
>   		v3d_perfmon_stop(v3d, perfmon, false);
>   
> +	/* If the global perfmon is being destroyed, set it to NULL */
> +	cmpxchg(&v3d->global_perfmon, perfmon, NULL);
> +
>   	v3d_perfmon_put(perfmon);
>   
>   	return 0;
> @@ -383,6 +386,7 @@ int v3d_perfmon_destroy_ioctl(struct drm_device *dev, void *data,
>   {
>   	struct v3d_file_priv *v3d_priv = file_priv->driver_priv;
>   	struct drm_v3d_perfmon_destroy *req = data;
> +	struct v3d_dev *v3d = v3d_priv->v3d;
>   	struct v3d_perfmon *perfmon;
>   
>   	mutex_lock(&v3d_priv->perfmon.lock);
> @@ -392,6 +396,13 @@ int v3d_perfmon_destroy_ioctl(struct drm_device *dev, void *data,
>   	if (!perfmon)
>   		return -EINVAL;
>   
> +	/* If the active perfmon is being destroyed, stop it first */
> +	if (perfmon == v3d->active_perfmon)
> +		v3d_perfmon_stop(v3d, perfmon, false);

Could you please move this snippet to different patch? This snippet is a
global fix as it can prevent NULL pointer dereferences triggered by the
user-space. I would like to push this snippet to drm-misc-fixes.

> +
> +	/* If the global perfmon is being destroyed, set it to NULL */
> +	cmpxchg(&v3d->global_perfmon, perfmon, NULL);
> +
>   	v3d_perfmon_put(perfmon);
>   
>   	return 0;
> @@ -451,3 +462,34 @@ int v3d_perfmon_get_counter_ioctl(struct drm_device *dev, void *data,
>   
>   	return 0;
>   }
> +
> +int v3d_perfmon_set_global_ioctl(struct drm_device *dev, void *data,
> +				 struct drm_file *file_priv)
> +{
> +	struct v3d_file_priv *v3d_priv = file_priv->driver_priv;
> +	struct drm_v3d_perfmon_set_global *req = data;
> +	struct v3d_dev *v3d = to_v3d_dev(dev);
> +	struct v3d_perfmon *perfmon;
> +
> +	if (req->flags & ~DRM_V3D_PERFMON_CLEAR_GLOBAL)
> +		return -EINVAL;
> +
> +	perfmon = v3d_perfmon_find(v3d_priv, req->id);
> +	if (!perfmon)
> +		return -EINVAL;
> +
> +	/* If the request is to clear the global performance monitor */
> +	if (req->flags & DRM_V3D_PERFMON_CLEAR_GLOBAL) {
> +		if (!v3d->global_perfmon)
> +			return -EINVAL;
> +
> +		xchg(&v3d->global_perfmon, NULL);

What if v3d->global_perfmon is running?

> +
> +		return 0;
> +	}
> +
> +	if (cmpxchg(&v3d->global_perfmon, NULL, perfmon))
> +		return -EBUSY;
> +
> +	return 0;
> +}

[...]

> diff --git a/include/uapi/drm/v3d_drm.h b/include/uapi/drm/v3d_drm.h
> index 87fc5bb0a61e..7c2ad9d0270d 100644
> --- a/include/uapi/drm/v3d_drm.h
> +++ b/include/uapi/drm/v3d_drm.h
> @@ -43,6 +43,7 @@ extern "C" {
>   #define DRM_V3D_PERFMON_GET_VALUES                0x0a
>   #define DRM_V3D_SUBMIT_CPU                        0x0b
>   #define DRM_V3D_PERFMON_GET_COUNTER               0x0c
> +#define DRM_V3D_PERFMON_SET_GLOBAL                0x0d
>   
>   #define DRM_IOCTL_V3D_SUBMIT_CL           DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_SUBMIT_CL, struct drm_v3d_submit_cl)
>   #define DRM_IOCTL_V3D_WAIT_BO             DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_WAIT_BO, struct drm_v3d_wait_bo)
> @@ -61,6 +62,8 @@ extern "C" {
>   #define DRM_IOCTL_V3D_SUBMIT_CPU          DRM_IOW(DRM_COMMAND_BASE + DRM_V3D_SUBMIT_CPU, struct drm_v3d_submit_cpu)
>   #define DRM_IOCTL_V3D_PERFMON_GET_COUNTER DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_PERFMON_GET_COUNTER, \
>   						   struct drm_v3d_perfmon_get_counter)
> +#define DRM_IOCTL_V3D_PERFMON_SET_GLOBAL  DRM_IOW(DRM_COMMAND_BASE + DRM_V3D_PERFMON_SET_GLOBAL, \
> +						   struct drm_v3d_perfmon_set_global)
>   
>   #define DRM_V3D_SUBMIT_CL_FLUSH_CACHE             0x01
>   #define DRM_V3D_SUBMIT_EXTENSION		  0x02
> @@ -765,6 +768,18 @@ struct drm_v3d_perfmon_get_counter {
>   	__u8 reserved[7];
>   };
>   
> +#define DRM_V3D_PERFMON_CLEAR_GLOBAL    0x0001
> +
> +/**
> + * struct drm_v3d_perfmon_set_global - ioctl to define a global performance
> + * monitor that is used for all job. If a global performance monitor is

s/job/jobs

Best Regards,
- Maíra

> + * defined, jobs with a self-defined performance monitor are not allowed.
> + */
> +struct drm_v3d_perfmon_set_global {
> +	__u32 flags;
> +	__u32 id;
> +};
> +
>   #if defined(__cplusplus)
>   }
>   #endif
Christian Gmeiner Nov. 18, 2024, 11:14 p.m. UTC | #2
Hi Maira,

>
> The patch overall LGTM, I just have one small nit.
>

Hopefully v4 will be the last iteration.

> On 17/11/24 18:41, Christian Gmeiner wrote:
> > From: Christian Gmeiner <cgmeiner@igalia.com>
> >
> > Add a new ioctl, DRM_IOCTL_V3D_PERFMON_SET_GLOBAL, to allow
> > configuration of a global performance monitor (perfmon).
> > Use the global perfmon for all jobs to ensure consistent
> > performance tracking across submissions. This feature is
> > needed to implement a Perfetto datasources in user-space.
> >
> > Signed-off-by: Christian Gmeiner <cgmeiner@igalia.com>
> > ---
> > Changes in v3:
> > - Reworked commit message.
> > - Refined some code comments.
> > - Added missing v3d_perfmon_stop(..) call to v3d_perfmon_destroy_ioctl(..).
> >
> > Changes in v2:
> > - Reworked commit message.
> > - Removed num_perfmon counter for tracking perfmon allocations.
> > - Allowing allocation of perfmons when the global perfmon is active.
> > - Return -EAGAIN for submissions with a per job perfmon if the global perfmon is active.
> > ---
> >
> > ---
> >   drivers/gpu/drm/v3d/v3d_drv.c     |  1 +
> >   drivers/gpu/drm/v3d/v3d_drv.h     |  8 ++++++
> >   drivers/gpu/drm/v3d/v3d_perfmon.c | 42 +++++++++++++++++++++++++++++++
> >   drivers/gpu/drm/v3d/v3d_sched.c   | 14 ++++++++---
> >   drivers/gpu/drm/v3d/v3d_submit.c  | 10 ++++++++
> >   include/uapi/drm/v3d_drm.h        | 15 +++++++++++
> >   6 files changed, 87 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
> > index d7ff1f5fa481..3c89f0daa5b8 100644
> > --- a/drivers/gpu/drm/v3d/v3d_drv.c
> > +++ b/drivers/gpu/drm/v3d/v3d_drv.c
> > @@ -214,6 +214,7 @@ static const struct drm_ioctl_desc v3d_drm_ioctls[] = {
> >       DRM_IOCTL_DEF_DRV(V3D_PERFMON_GET_VALUES, v3d_perfmon_get_values_ioctl, DRM_RENDER_ALLOW),
> >       DRM_IOCTL_DEF_DRV(V3D_SUBMIT_CPU, v3d_submit_cpu_ioctl, DRM_RENDER_ALLOW | DRM_AUTH),
> >       DRM_IOCTL_DEF_DRV(V3D_PERFMON_GET_COUNTER, v3d_perfmon_get_counter_ioctl, DRM_RENDER_ALLOW),
> > +     DRM_IOCTL_DEF_DRV(V3D_PERFMON_SET_GLOBAL, v3d_perfmon_set_global_ioctl, DRM_RENDER_ALLOW),
> >   };
> >
> >   static const struct drm_driver v3d_drm_driver = {
> > diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
> > index cf4b23369dc4..a0d920ec2b1d 100644
> > --- a/drivers/gpu/drm/v3d/v3d_drv.h
> > +++ b/drivers/gpu/drm/v3d/v3d_drv.h
> > @@ -179,6 +179,12 @@ struct v3d_dev {
> >               u32 num_allocated;
> >               u32 pages_allocated;
> >       } bo_stats;
> > +
> > +     /* To support a performance analysis tool in user space, we require
> > +      * a single, globally configured performance monitor (perfmon) for
> > +      * all jobs.
> > +      */
> > +     struct v3d_perfmon *global_perfmon;
> >   };
> >
> >   static inline struct v3d_dev *
> > @@ -584,6 +590,8 @@ int v3d_perfmon_get_values_ioctl(struct drm_device *dev, void *data,
> >                                struct drm_file *file_priv);
> >   int v3d_perfmon_get_counter_ioctl(struct drm_device *dev, void *data,
> >                                 struct drm_file *file_priv);
> > +int v3d_perfmon_set_global_ioctl(struct drm_device *dev, void *data,
> > +                              struct drm_file *file_priv);
> >
> >   /* v3d_sysfs.c */
> >   int v3d_sysfs_init(struct device *dev);
> > diff --git a/drivers/gpu/drm/v3d/v3d_perfmon.c b/drivers/gpu/drm/v3d/v3d_perfmon.c
> > index 156be13ab2ef..df72171d8c80 100644
> > --- a/drivers/gpu/drm/v3d/v3d_perfmon.c
> > +++ b/drivers/gpu/drm/v3d/v3d_perfmon.c
> > @@ -312,6 +312,9 @@ static int v3d_perfmon_idr_del(int id, void *elem, void *data)
> >       if (perfmon == v3d->active_perfmon)
> >               v3d_perfmon_stop(v3d, perfmon, false);
> >
> > +     /* If the global perfmon is being destroyed, set it to NULL */
> > +     cmpxchg(&v3d->global_perfmon, perfmon, NULL);
> > +
> >       v3d_perfmon_put(perfmon);
> >
> >       return 0;
> > @@ -383,6 +386,7 @@ int v3d_perfmon_destroy_ioctl(struct drm_device *dev, void *data,
> >   {
> >       struct v3d_file_priv *v3d_priv = file_priv->driver_priv;
> >       struct drm_v3d_perfmon_destroy *req = data;
> > +     struct v3d_dev *v3d = v3d_priv->v3d;
> >       struct v3d_perfmon *perfmon;
> >
> >       mutex_lock(&v3d_priv->perfmon.lock);
> > @@ -392,6 +396,13 @@ int v3d_perfmon_destroy_ioctl(struct drm_device *dev, void *data,
> >       if (!perfmon)
> >               return -EINVAL;
> >
> > +     /* If the active perfmon is being destroyed, stop it first */
> > +     if (perfmon == v3d->active_perfmon)
> > +             v3d_perfmon_stop(v3d, perfmon, false);
>
> Could you please move this snippet to different patch? This snippet is a
> global fix as it can prevent NULL pointer dereferences triggered by the
> user-space. I would like to push this snippet to drm-misc-fixes.
>

Done.

> > +
> > +     /* If the global perfmon is being destroyed, set it to NULL */
> > +     cmpxchg(&v3d->global_perfmon, perfmon, NULL);
> > +
> >       v3d_perfmon_put(perfmon);
> >
> >       return 0;
> > @@ -451,3 +462,34 @@ int v3d_perfmon_get_counter_ioctl(struct drm_device *dev, void *data,
> >
> >       return 0;
> >   }
> > +
> > +int v3d_perfmon_set_global_ioctl(struct drm_device *dev, void *data,
> > +                              struct drm_file *file_priv)
> > +{
> > +     struct v3d_file_priv *v3d_priv = file_priv->driver_priv;
> > +     struct drm_v3d_perfmon_set_global *req = data;
> > +     struct v3d_dev *v3d = to_v3d_dev(dev);
> > +     struct v3d_perfmon *perfmon;
> > +
> > +     if (req->flags & ~DRM_V3D_PERFMON_CLEAR_GLOBAL)
> > +             return -EINVAL;
> > +
> > +     perfmon = v3d_perfmon_find(v3d_priv, req->id);
> > +     if (!perfmon)
> > +             return -EINVAL;
> > +
> > +     /* If the request is to clear the global performance monitor */
> > +     if (req->flags & DRM_V3D_PERFMON_CLEAR_GLOBAL) {
> > +             if (!v3d->global_perfmon)
> > +                     return -EINVAL;
> > +
> > +             xchg(&v3d->global_perfmon, NULL);
>
> What if v3d->global_perfmon is running?
>

It will be stopped by the next job that hits v3d_switch_perfmon(..).

> > +
> > +             return 0;
> > +     }
> > +
> > +     if (cmpxchg(&v3d->global_perfmon, NULL, perfmon))
> > +             return -EBUSY;
> > +
> > +     return 0;
> > +}
>
> [...]
>
> > diff --git a/include/uapi/drm/v3d_drm.h b/include/uapi/drm/v3d_drm.h
> > index 87fc5bb0a61e..7c2ad9d0270d 100644
> > --- a/include/uapi/drm/v3d_drm.h
> > +++ b/include/uapi/drm/v3d_drm.h
> > @@ -43,6 +43,7 @@ extern "C" {
> >   #define DRM_V3D_PERFMON_GET_VALUES                0x0a
> >   #define DRM_V3D_SUBMIT_CPU                        0x0b
> >   #define DRM_V3D_PERFMON_GET_COUNTER               0x0c
> > +#define DRM_V3D_PERFMON_SET_GLOBAL                0x0d
> >
> >   #define DRM_IOCTL_V3D_SUBMIT_CL           DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_SUBMIT_CL, struct drm_v3d_submit_cl)
> >   #define DRM_IOCTL_V3D_WAIT_BO             DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_WAIT_BO, struct drm_v3d_wait_bo)
> > @@ -61,6 +62,8 @@ extern "C" {
> >   #define DRM_IOCTL_V3D_SUBMIT_CPU          DRM_IOW(DRM_COMMAND_BASE + DRM_V3D_SUBMIT_CPU, struct drm_v3d_submit_cpu)
> >   #define DRM_IOCTL_V3D_PERFMON_GET_COUNTER DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_PERFMON_GET_COUNTER, \
> >                                                  struct drm_v3d_perfmon_get_counter)
> > +#define DRM_IOCTL_V3D_PERFMON_SET_GLOBAL  DRM_IOW(DRM_COMMAND_BASE + DRM_V3D_PERFMON_SET_GLOBAL, \
> > +                                                struct drm_v3d_perfmon_set_global)
> >
> >   #define DRM_V3D_SUBMIT_CL_FLUSH_CACHE             0x01
> >   #define DRM_V3D_SUBMIT_EXTENSION              0x02
> > @@ -765,6 +768,18 @@ struct drm_v3d_perfmon_get_counter {
> >       __u8 reserved[7];
> >   };
> >
> > +#define DRM_V3D_PERFMON_CLEAR_GLOBAL    0x0001
> > +
> > +/**
> > + * struct drm_v3d_perfmon_set_global - ioctl to define a global performance
> > + * monitor that is used for all job. If a global performance monitor is
>
> s/job/jobs
>

Ah.. thanks.

> Best Regards,
> - Maíra
>
> > + * defined, jobs with a self-defined performance monitor are not allowed.
> > + */
> > +struct drm_v3d_perfmon_set_global {
> > +     __u32 flags;
> > +     __u32 id;
> > +};
> > +
> >   #if defined(__cplusplus)
> >   }
> >   #endif
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
index d7ff1f5fa481..3c89f0daa5b8 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.c
+++ b/drivers/gpu/drm/v3d/v3d_drv.c
@@ -214,6 +214,7 @@  static const struct drm_ioctl_desc v3d_drm_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(V3D_PERFMON_GET_VALUES, v3d_perfmon_get_values_ioctl, DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(V3D_SUBMIT_CPU, v3d_submit_cpu_ioctl, DRM_RENDER_ALLOW | DRM_AUTH),
 	DRM_IOCTL_DEF_DRV(V3D_PERFMON_GET_COUNTER, v3d_perfmon_get_counter_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(V3D_PERFMON_SET_GLOBAL, v3d_perfmon_set_global_ioctl, DRM_RENDER_ALLOW),
 };
 
 static const struct drm_driver v3d_drm_driver = {
diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
index cf4b23369dc4..a0d920ec2b1d 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.h
+++ b/drivers/gpu/drm/v3d/v3d_drv.h
@@ -179,6 +179,12 @@  struct v3d_dev {
 		u32 num_allocated;
 		u32 pages_allocated;
 	} bo_stats;
+
+	/* To support a performance analysis tool in user space, we require
+	 * a single, globally configured performance monitor (perfmon) for
+	 * all jobs.
+	 */
+	struct v3d_perfmon *global_perfmon;
 };
 
 static inline struct v3d_dev *
@@ -584,6 +590,8 @@  int v3d_perfmon_get_values_ioctl(struct drm_device *dev, void *data,
 				 struct drm_file *file_priv);
 int v3d_perfmon_get_counter_ioctl(struct drm_device *dev, void *data,
 				  struct drm_file *file_priv);
+int v3d_perfmon_set_global_ioctl(struct drm_device *dev, void *data,
+				 struct drm_file *file_priv);
 
 /* v3d_sysfs.c */
 int v3d_sysfs_init(struct device *dev);
diff --git a/drivers/gpu/drm/v3d/v3d_perfmon.c b/drivers/gpu/drm/v3d/v3d_perfmon.c
index 156be13ab2ef..df72171d8c80 100644
--- a/drivers/gpu/drm/v3d/v3d_perfmon.c
+++ b/drivers/gpu/drm/v3d/v3d_perfmon.c
@@ -312,6 +312,9 @@  static int v3d_perfmon_idr_del(int id, void *elem, void *data)
 	if (perfmon == v3d->active_perfmon)
 		v3d_perfmon_stop(v3d, perfmon, false);
 
+	/* If the global perfmon is being destroyed, set it to NULL */
+	cmpxchg(&v3d->global_perfmon, perfmon, NULL);
+
 	v3d_perfmon_put(perfmon);
 
 	return 0;
@@ -383,6 +386,7 @@  int v3d_perfmon_destroy_ioctl(struct drm_device *dev, void *data,
 {
 	struct v3d_file_priv *v3d_priv = file_priv->driver_priv;
 	struct drm_v3d_perfmon_destroy *req = data;
+	struct v3d_dev *v3d = v3d_priv->v3d;
 	struct v3d_perfmon *perfmon;
 
 	mutex_lock(&v3d_priv->perfmon.lock);
@@ -392,6 +396,13 @@  int v3d_perfmon_destroy_ioctl(struct drm_device *dev, void *data,
 	if (!perfmon)
 		return -EINVAL;
 
+	/* If the active perfmon is being destroyed, stop it first */
+	if (perfmon == v3d->active_perfmon)
+		v3d_perfmon_stop(v3d, perfmon, false);
+
+	/* If the global perfmon is being destroyed, set it to NULL */
+	cmpxchg(&v3d->global_perfmon, perfmon, NULL);
+
 	v3d_perfmon_put(perfmon);
 
 	return 0;
@@ -451,3 +462,34 @@  int v3d_perfmon_get_counter_ioctl(struct drm_device *dev, void *data,
 
 	return 0;
 }
+
+int v3d_perfmon_set_global_ioctl(struct drm_device *dev, void *data,
+				 struct drm_file *file_priv)
+{
+	struct v3d_file_priv *v3d_priv = file_priv->driver_priv;
+	struct drm_v3d_perfmon_set_global *req = data;
+	struct v3d_dev *v3d = to_v3d_dev(dev);
+	struct v3d_perfmon *perfmon;
+
+	if (req->flags & ~DRM_V3D_PERFMON_CLEAR_GLOBAL)
+		return -EINVAL;
+
+	perfmon = v3d_perfmon_find(v3d_priv, req->id);
+	if (!perfmon)
+		return -EINVAL;
+
+	/* If the request is to clear the global performance monitor */
+	if (req->flags & DRM_V3D_PERFMON_CLEAR_GLOBAL) {
+		if (!v3d->global_perfmon)
+			return -EINVAL;
+
+		xchg(&v3d->global_perfmon, NULL);
+
+		return 0;
+	}
+
+	if (cmpxchg(&v3d->global_perfmon, NULL, perfmon))
+		return -EBUSY;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
index 08d2a2739582..38690740f593 100644
--- a/drivers/gpu/drm/v3d/v3d_sched.c
+++ b/drivers/gpu/drm/v3d/v3d_sched.c
@@ -120,11 +120,19 @@  v3d_cpu_job_free(struct drm_sched_job *sched_job)
 static void
 v3d_switch_perfmon(struct v3d_dev *v3d, struct v3d_job *job)
 {
-	if (job->perfmon != v3d->active_perfmon)
+	struct v3d_perfmon *perfmon = v3d->global_perfmon;
+
+	if (!perfmon)
+		perfmon = job->perfmon;
+
+	if (perfmon == v3d->active_perfmon)
+		return;
+
+	if (perfmon != v3d->active_perfmon)
 		v3d_perfmon_stop(v3d, v3d->active_perfmon, true);
 
-	if (job->perfmon && v3d->active_perfmon != job->perfmon)
-		v3d_perfmon_start(v3d, job->perfmon);
+	if (perfmon && v3d->active_perfmon != perfmon)
+		v3d_perfmon_start(v3d, perfmon);
 }
 
 static void
diff --git a/drivers/gpu/drm/v3d/v3d_submit.c b/drivers/gpu/drm/v3d/v3d_submit.c
index d607aa9c4ec2..9e439c9f0a93 100644
--- a/drivers/gpu/drm/v3d/v3d_submit.c
+++ b/drivers/gpu/drm/v3d/v3d_submit.c
@@ -981,6 +981,11 @@  v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 		goto fail;
 
 	if (args->perfmon_id) {
+		if (v3d->global_perfmon) {
+			ret = -EAGAIN;
+			goto fail_perfmon;
+		}
+
 		render->base.perfmon = v3d_perfmon_find(v3d_priv,
 							args->perfmon_id);
 
@@ -1196,6 +1201,11 @@  v3d_submit_csd_ioctl(struct drm_device *dev, void *data,
 		goto fail;
 
 	if (args->perfmon_id) {
+		if (v3d->global_perfmon) {
+			ret = -EAGAIN;
+			goto fail_perfmon;
+		}
+
 		job->base.perfmon = v3d_perfmon_find(v3d_priv,
 						     args->perfmon_id);
 		if (!job->base.perfmon) {
diff --git a/include/uapi/drm/v3d_drm.h b/include/uapi/drm/v3d_drm.h
index 87fc5bb0a61e..7c2ad9d0270d 100644
--- a/include/uapi/drm/v3d_drm.h
+++ b/include/uapi/drm/v3d_drm.h
@@ -43,6 +43,7 @@  extern "C" {
 #define DRM_V3D_PERFMON_GET_VALUES                0x0a
 #define DRM_V3D_SUBMIT_CPU                        0x0b
 #define DRM_V3D_PERFMON_GET_COUNTER               0x0c
+#define DRM_V3D_PERFMON_SET_GLOBAL                0x0d
 
 #define DRM_IOCTL_V3D_SUBMIT_CL           DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_SUBMIT_CL, struct drm_v3d_submit_cl)
 #define DRM_IOCTL_V3D_WAIT_BO             DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_WAIT_BO, struct drm_v3d_wait_bo)
@@ -61,6 +62,8 @@  extern "C" {
 #define DRM_IOCTL_V3D_SUBMIT_CPU          DRM_IOW(DRM_COMMAND_BASE + DRM_V3D_SUBMIT_CPU, struct drm_v3d_submit_cpu)
 #define DRM_IOCTL_V3D_PERFMON_GET_COUNTER DRM_IOWR(DRM_COMMAND_BASE + DRM_V3D_PERFMON_GET_COUNTER, \
 						   struct drm_v3d_perfmon_get_counter)
+#define DRM_IOCTL_V3D_PERFMON_SET_GLOBAL  DRM_IOW(DRM_COMMAND_BASE + DRM_V3D_PERFMON_SET_GLOBAL, \
+						   struct drm_v3d_perfmon_set_global)
 
 #define DRM_V3D_SUBMIT_CL_FLUSH_CACHE             0x01
 #define DRM_V3D_SUBMIT_EXTENSION		  0x02
@@ -765,6 +768,18 @@  struct drm_v3d_perfmon_get_counter {
 	__u8 reserved[7];
 };
 
+#define DRM_V3D_PERFMON_CLEAR_GLOBAL    0x0001
+
+/**
+ * struct drm_v3d_perfmon_set_global - ioctl to define a global performance
+ * monitor that is used for all job. If a global performance monitor is
+ * defined, jobs with a self-defined performance monitor are not allowed.
+ */
+struct drm_v3d_perfmon_set_global {
+	__u32 flags;
+	__u32 id;
+};
+
 #if defined(__cplusplus)
 }
 #endif