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

[James Zhu]

On 2023-11-22 17:40, Felix Kuehling wrote:
> On 2023-11-03 09:11, James Zhu wrote:
>> From: David Yat Sin <david.yatsin at amd.com>
>>
>> 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 at amd.com>
>> Signed-off-by: James Zhu <James.Zhu at amd.com>
>> ---
>>   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