Re: [PATCH 23/24] drm/amdkfd: add pc sampling capability check

[James Zhu <jamesz@xxxxxxx>]

On 2023-11-22 17:40, Felix Kuehling wrote:
> On 2023-11-03 09:11, James Zhu wrote:
> > From: David Yat Sin <david.yatsin@xxxxxxx>
> >
> > Add pc sampling capability check.
>
> This should be squashed into patch 2. Or if you want to keep it 
> separate, put this patch before patch 2 and define 
> AMDKFD_IOC_PC_SAMPLE with KFD_IOC_FLAG_PERFMON from the beginning.
[JZ] will do , thanks!
> Regards,
>   Felix
>
>
> > Signed-off-by: David Yat Sin <david.yatsin@xxxxxxx>
> > Signed-off-by: James Zhu <James.Zhu@xxxxxxx>
> > ---
> >   drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 10 +++++++++-
> >   drivers/gpu/drm/amd/amdkfd/kfd_priv.h    | 13 +++++++++++++
> >   2 files changed, 22 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c 
> > b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> > index b00390e451bf..5e47e374d824 100644
> > --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
> > @@ -3259,7 +3259,7 @@ static const struct amdkfd_ioctl_desc 
> > amdkfd_ioctls[] = {
> >               kfd_ioctl_set_debug_trap, 0),
> >         AMDKFD_IOCTL_DEF(AMDKFD_IOC_PC_SAMPLE,
> > -            kfd_ioctl_pc_sample, 0),
> > +            kfd_ioctl_pc_sample, KFD_IOC_FLAG_PERFMON),
> >   };
> >     #define AMDKFD_CORE_IOCTL_COUNT    ARRAY_SIZE(amdkfd_ioctls)
> > @@ -3336,6 +3336,14 @@ static long kfd_ioctl(struct file *filep, 
> > unsigned int cmd, unsigned long arg)
> >           }
> >       }
> >   +    /* PC Sampling Monitor */
> > +    if (unlikely(ioctl->flags & KFD_IOC_FLAG_PERFMON)) {
> > +        if (!capable(CAP_PERFMON) && !capable(CAP_SYS_ADMIN)) {
> > +            retcode = -EACCES;
> > +            goto err_i1;
> > +        }
> > +    }
> > +
> >       if (cmd & (IOC_IN | IOC_OUT)) {
> >           if (asize <= sizeof(stack_kdata)) {
> >               kdata = stack_kdata;
> > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h 
> > b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> > index b7062033fda4..236d3de85153 100644
> > --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
> > @@ -144,6 +144,19 @@ enum kfd_ioctl_flags {
> >        * we also allow ioctls with SYS_ADMIN capability.
> >        */
> >       KFD_IOC_FLAG_CHECKPOINT_RESTORE = BIT(0),
> > +
> > +    /*
> > +     * @KFD_IOC_FLAG_PERFMON:
> > +     * Performance monitoring feature, GPU performance monitoring 
> > can allow users
> > +     * to gather some information about other processes. PC sampling 
> > can allow
> > +     * users to infer information about wavefronts from other 
> > processes that are
> > +     * running on the same CUs, such as which execution units they 
> > are using. As
> > +     * such, this type of performance monitoring should be protected 
> > and only
> > +     * available to users with sufficient capabilities: either 
> > CAP_PERFMON, or,
> > +     * for backwards compatibility, CAP_SYS_ADMIN.
> > +     */
> > +
> > +    KFD_IOC_FLAG_PERFMON = BIT(1),
> >   };
> >   /*
> >    * Kernel module parameter to specify maximum number of supported 
> > queues per