[PATCH 07/13] drm/amdgpu/userq: enable support for queue priorities

[Alex Deucher]

On Fri, Apr 11, 2025 at 1:18 PM Khatri, Sunil <sukhatri at amd.com> wrote:
>
> A small comment otherwise it looks great.
> Reviewed-by: Sunil Khatri <sunil.khatri at amd.com>
>
> On 4/11/2025 12:23 AM, Alex Deucher wrote:
> > Enable users to create queues at different priority levels.
> > The highest level is restricted to drm master.
> >
> > Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 26 ++++++++++++++++++-
> >   1 file changed, 25 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> > index 57a4ef64e0b8b..b8b13b6ab4631 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> > @@ -22,6 +22,7 @@
> >    *
> >    */
> >
> > +#include <drm/drm_auth.h>
> >   #include <drm/drm_exec.h>
> >   #include "amdgpu.h"
> >   #include "amdgpu_vm.h"
> > @@ -260,6 +261,21 @@ amdgpu_userqueue_destroy(struct drm_file *filp, int queue_id)
> >       return r;
> >   }
> >
> > +static int amdgpu_userq_priority_permit(struct drm_file *filp,
> > +                                     int priority)
> > Do we want this value of priority to be unsigned as we only want values >=0.

The values we pass in will always be >=0.

Alex

> > +{
> > +     if (priority < AMDGPU_USERQ_CREATE_FLAGS_QUEUE_PRIORITY_HIGH)
> > +             return 0;
> > +
> > +     if (capable(CAP_SYS_NICE))
> > +             return 0;
> > +
> > +     if (drm_is_current_master(filp))
> > +             return 0;
> > +
> > +     return -EACCES;
> > +}
> > +
> >   static int
> >   amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
> >   {
> > @@ -271,6 +287,9 @@ amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
> >       struct amdgpu_db_info db_info;
> >       uint64_t index;
> >       int qid, r = 0;
> > +     int priority =
> > +             (args->in.flags & AMDGPU_USERQ_CREATE_FLAGS_QUEUE_PRIORITY_MASK) >>
> > +             AMDGPU_USERQ_CREATE_FLAGS_QUEUE_PRIORITY_SHIFT;
> >
> >       /* Usermode queues are only supported for GFX IP as of now */
> >       if (args->in.ip_type != AMDGPU_HW_IP_GFX &&
> > @@ -280,6 +299,10 @@ amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
> >               return -EINVAL;
> >       }
> >
> > +     r = amdgpu_userq_priority_permit(filp, priority);
> > +     if (r)
> > +             return r;
> > +
> >       /*
> >        * There could be a situation that we are creating a new queue while
> >        * the other queues under this UQ_mgr are suspended. So if there is any
> > @@ -305,6 +328,7 @@ amdgpu_userqueue_create(struct drm_file *filp, union drm_amdgpu_userq *args)
> >       queue->doorbell_handle = args->in.doorbell_handle;
> >       queue->queue_type = args->in.ip_type;
> >       queue->vm = &fpriv->vm;
> > +     queue->priority = priority;
> >
> >       db_info.queue_type = queue->queue_type;
> >       db_info.doorbell_handle = queue->doorbell_handle;
> > @@ -377,7 +401,7 @@ int amdgpu_userq_ioctl(struct drm_device *dev, void *data,
> >
> >       switch (args->in.op) {
> >       case AMDGPU_USERQ_OP_CREATE:
> > -             if (args->in.flags)
> > +             if (args->in.flags & ~AMDGPU_USERQ_CREATE_FLAGS_QUEUE_PRIORITY_MASK)
> >                       return -EINVAL;
> >               r = amdgpu_userqueue_create(filp, args);
> >               if (r)