Re: [PATCH v5 04/10] drm/amdgpu: create GFX-gen11 usermode queue

[Shashank Sharma <shashank.sharma@amd.com>]

On 07/07/2023 14:28, Christian König wrote:
>
>
> Am 07.07.23 um 12:02 schrieb Shashank Sharma:
>>
>> On 07/07/2023 10:37, Christian König wrote:
>>> Am 07.07.23 um 09:46 schrieb Shashank Sharma:
>>>>
>>>> On 07/07/2023 09:24, Christian König wrote:
>>>>>
>>>>>
>>>>> Am 06.07.23 um 14:35 schrieb Shashank Sharma:
>>>>>> A Memory queue descriptor (MQD) of a userqueue defines it in
>>>>>> the hw's context. As MQD format can vary between different
>>>>>> graphics IPs, we need gfx GEN specific handlers to create MQDs.
>>>>>>
>>>>>> This patch:
>>>>>> - Introduces MQD handler functions for the usermode queues.
>>>>>> - Adds new functions to create and destroy userqueue MQD for
>>>>>>    GFX-GEN-11 IP
>>>>>>
>>>>>> V1: Worked on review comments from Alex:
>>>>>>      - Make MQD functions GEN and IP specific
>>>>>>
>>>>>> V2: Worked on review comments from Alex:
>>>>>>      - Reuse the existing adev->mqd[ip] for MQD creation
>>>>>>      - Formatting and arrangement of code
>>>>>>
>>>>>> V3:
>>>>>>      - Integration with doorbell manager
>>>>>>
>>>>>> V4: Review comments addressed:
>>>>>>      - Do not create a new file for userq, reuse gfx_v11_0.c (Alex)
>>>>>>      - Align name of structure members (Luben)
>>>>>>      - Don't break up the Cc tag list and the Sob tag list in commit
>>>>>>        message (Luben)
>>>>>> V5:
>>>>>>     - No need to reserve the bo for MQD (Christian).
>>>>>>     - Some more changes to support IP specific MQD creation.
>>>>>>
>>>>>> Cc: Alex Deucher <alexander.deucher@amd.com>
>>>>>> Cc: Christian Koenig <christian.koenig@amd.com>
>>>>>> Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
>>>>>> Signed-off-by: Arvind Yadav <arvind.yadav@amd.com>
>>>>>> ---
>>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 16 ++++
>>>>>>   drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c        | 73 
>>>>>> +++++++++++++++++++
>>>>>>   .../gpu/drm/amd/include/amdgpu_userqueue.h    |  7 ++
>>>>>>   3 files changed, 96 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c 
>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
>>>>>> index e37b5da5a0d0..bb774144c372 100644
>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
>>>>>> @@ -134,12 +134,28 @@ int amdgpu_userq_ioctl(struct drm_device 
>>>>>> *dev, void *data,
>>>>>>       return r;
>>>>>>   }
>>>>>>   +extern const struct amdgpu_userq_funcs userq_gfx_v11_funcs;
>>>>>> +
>>>>>> +static void
>>>>>> +amdgpu_userqueue_setup_gfx(struct amdgpu_userq_mgr *uq_mgr)
>>>>>> +{
>>>>>> +    int maj;
>>>>>> +    struct amdgpu_device *adev = uq_mgr->adev;
>>>>>> +    uint32_t version = adev->ip_versions[GC_HWIP][0];
>>>>>> +
>>>>>> +    /* We support usermode queue only for GFX V11 as of now */
>>>>>> +    maj = IP_VERSION_MAJ(version);
>>>>>> +    if (maj == 11)
>>>>>> +        uq_mgr->userq_funcs[AMDGPU_HW_IP_GFX] = 
>>>>>> &userq_gfx_v11_funcs;
>>>>>> +}
>>>>>> +
>>>>>>   int amdgpu_userq_mgr_init(struct amdgpu_userq_mgr *userq_mgr, 
>>>>>> struct amdgpu_device *adev)
>>>>>>   {
>>>>>>       mutex_init(&userq_mgr->userq_mutex);
>>>>>>       idr_init_base(&userq_mgr->userq_idr, 1);
>>>>>>       userq_mgr->adev = adev;
>>>>>>   +    amdgpu_userqueue_setup_gfx(userq_mgr);
>>>>>>       return 0;
>>>>>>   }
>>>>>>   diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c 
>>>>>> b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
>>>>>> index c4940b6ea1c4..e76e1b86b434 100644
>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
>>>>>> @@ -30,6 +30,7 @@
>>>>>>   #include "amdgpu_psp.h"
>>>>>>   #include "amdgpu_smu.h"
>>>>>>   #include "amdgpu_atomfirmware.h"
>>>>>> +#include "amdgpu_userqueue.h"
>>>>>>   #include "imu_v11_0.h"
>>>>>>   #include "soc21.h"
>>>>>>   #include "nvd.h"
>>>>>> @@ -6486,3 +6487,75 @@ const struct amdgpu_ip_block_version 
>>>>>> gfx_v11_0_ip_block =
>>>>>>       .rev = 0,
>>>>>>       .funcs = &gfx_v11_0_ip_funcs,
>>>>>>   };
>>>>>> +
>>>>>> +static int gfx_v11_0_userq_mqd_create(struct amdgpu_userq_mgr 
>>>>>> *uq_mgr,
>>>>>> +                      struct drm_amdgpu_userq_in *args_in,
>>>>>> +                      struct amdgpu_usermode_queue *queue)
>>>>>> +{
>>>>>> +    struct amdgpu_device *adev = uq_mgr->adev;
>>>>>> +    struct amdgpu_mqd *mqd_gfx_generic = 
>>>>>> &adev->mqds[AMDGPU_HW_IP_GFX];
>>>>>> +    struct drm_amdgpu_userq_mqd_gfx_v11_0 mqd_user;
>>>>>> +    struct amdgpu_mqd_prop userq_props;
>>>>>> +    int r;
>>>>>> +
>>>>>> +    /* Incoming MQD parameters from userspace to be saved here */
>>>>>> +    memset(&mqd_user, 0, sizeof(mqd_user));
>>>>>> +
>>>>>> +    /* Structure to initialize MQD for userqueue using generic 
>>>>>> MQD init function */
>>>>>> +    memset(&userq_props, 0, sizeof(userq_props));
>>>>>> +
>>>>>> +    if (args_in->mqd_size != sizeof(struct 
>>>>>> drm_amdgpu_userq_mqd_gfx_v11_0)) {
>>>>>> +        DRM_ERROR("MQD size mismatch\n");
>>>>>> +        return -EINVAL;
>>>>>> +    }
>>>>>> +
>>>>>> +    if (copy_from_user(&mqd_user, u64_to_user_ptr(args_in->mqd), 
>>>>>> args_in->mqd_size)) {
>>>>>> +        DRM_ERROR("Failed to get user MQD\n");
>>>>>> +        return -EFAULT;
>>>>>> +    }
>>>>>
>>>>> Sorry, I've just seen that now. Please don't have a 
>>>>> copy_from_user() in the backend!
>>>>>
>>>>> This is pure front end stuff which we shouldn't do in hw 
>>>>> generation specific code.
>>>>>
>>>> This is a bit difficult to achieve, as you know:
>>>>
>>>> - the whole reason we moved to ptr/size based approach from 
>>>> fix-mqd-structure approach is so that we can support multiple MQD 
>>>> structures using the same UAPI.
>>>>
>>>> - which means that in file amdgpu_userqueue.c layer (say front-end) 
>>>> I do not know what is the right size of MQD, its independent of IP.
>>>>
>>>> - the correct size of MQD can only be known in IP specific 
>>>> functions which are in gfx_v11.c (back end).
>>>>
>>>> - I may be able to achieve it by adding a new fptr get_mqd_size() 
>>>> which can return the right MQD size for me from backend IP 
>>>> function, and then I can move this copy from user to front-end. 
>>>> Does it sound like a good idea to you ?
>>>
>>> Just use memdup_user() in the frontend. Allocating structures which 
>>> are copied from userspace on the stack is usually a bad idea as well.
>>>
>>> Then pass in the kernel ptr and size as argument here and validate 
>>> if what userspace gave us is correct.
>>>
>> This can still allow the user to pass invalid size (0 or too big), 
>> how to prevent that ? I can still add a check for 0 size, but how 
>> about a very big but invalid size for MQD ?
>
> memdup_user() already takes care of that (has a maximum of 2MiB IIRC) 
> and the hw specific function should still validate the size to filter 
> out 0 and other invalid values.


Perfect, I will change it.

- Shashank

>
> Christian.
>
>>
>> - Shashank
>>
>>> Regards,
>>> Christian.
>>>
>>>>
>>>> - Shashank
>>>>
>>>>> Regards,
>>>>> Christian.
>>>>>
>>>>>> +
>>>>>> +    /* Create BO for actual Userqueue MQD now */
>>>>>> +    r = amdgpu_bo_create_kernel(adev, mqd_gfx_generic->mqd_size, 
>>>>>> PAGE_SIZE,
>>>>>> +                    AMDGPU_GEM_DOMAIN_GTT,
>>>>>> +                    &queue->mqd.obj,
>>>>>> +                    &queue->mqd.gpu_addr,
>>>>>> +                    &queue->mqd.cpu_ptr);
>>>>>> +    if (r) {
>>>>>> +        DRM_ERROR("Failed to allocate BO for userqueue (%d)", r);
>>>>>> +        return -ENOMEM;
>>>>>> +    }
>>>>>> +    memset(queue->mqd.cpu_ptr, 0, mqd_gfx_generic->mqd_size);
>>>>>> +
>>>>>> +    /* Initialize the MQD BO with user given values */
>>>>>> +    userq_props.wptr_gpu_addr = mqd_user.wptr_va;
>>>>>> +    userq_props.rptr_gpu_addr = mqd_user.rptr_va;
>>>>>> +    userq_props.queue_size = mqd_user.queue_size;
>>>>>> +    userq_props.hqd_base_gpu_addr = mqd_user.queue_va;
>>>>>> +    userq_props.mqd_gpu_addr = queue->mqd.gpu_addr;
>>>>>> +    userq_props.use_doorbell = true;
>>>>>> +
>>>>>> +    r = mqd_gfx_generic->init_mqd(adev, (void 
>>>>>> *)queue->mqd.cpu_ptr, &userq_props);
>>>>>> +    if (r) {
>>>>>> +        DRM_ERROR("Failed to initialize MQD for userqueue\n");
>>>>>> +        goto free_mqd;
>>>>>> +    }
>>>>>> +
>>>>>> +    return 0;
>>>>>> +
>>>>>> +free_mqd:
>>>>>> +    amdgpu_bo_free_kernel(&queue->mqd.obj, &queue->mqd.gpu_addr, 
>>>>>> &queue->mqd.cpu_ptr);
>>>>>> +    return r;
>>>>>> +}
>>>>>> +
>>>>>> +static void
>>>>>> +gfx_v11_0_userq_mqd_destroy(struct amdgpu_userq_mgr *uq_mgr, 
>>>>>> struct amdgpu_usermode_queue *queue)
>>>>>> +{
>>>>>> +    struct amdgpu_userq_obj *mqd = &queue->mqd;
>>>>>> +
>>>>>> +    amdgpu_bo_free_kernel(&mqd->obj, &mqd->gpu_addr, 
>>>>>> &mqd->cpu_ptr);
>>>>>> +}
>>>>>> +
>>>>>> +const struct amdgpu_userq_funcs userq_gfx_v11_funcs = {
>>>>>> +    .mqd_create = gfx_v11_0_userq_mqd_create,
>>>>>> +    .mqd_destroy = gfx_v11_0_userq_mqd_destroy,
>>>>>> +};
>>>>>> diff --git a/drivers/gpu/drm/amd/include/amdgpu_userqueue.h 
>>>>>> b/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
>>>>>> index 55ed6512a565..240f92796f00 100644
>>>>>> --- a/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
>>>>>> +++ b/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
>>>>>> @@ -29,6 +29,12 @@
>>>>>>     struct amdgpu_mqd_prop;
>>>>>>   +struct amdgpu_userq_obj {
>>>>>> +    void         *cpu_ptr;
>>>>>> +    uint64_t     gpu_addr;
>>>>>> +    struct amdgpu_bo *obj;
>>>>>> +};
>>>>>> +
>>>>>>   struct amdgpu_usermode_queue {
>>>>>>       int            queue_type;
>>>>>>       uint64_t        doorbell_handle;
>>>>>> @@ -37,6 +43,7 @@ struct amdgpu_usermode_queue {
>>>>>>       struct amdgpu_mqd_prop    *userq_prop;
>>>>>>       struct amdgpu_userq_mgr *userq_mgr;
>>>>>>       struct amdgpu_vm    *vm;
>>>>>> +    struct amdgpu_userq_obj mqd;
>>>>>>   };
>>>>>>     struct amdgpu_userq_funcs {
>>>>>
>>>
>