Re: [RFC 2/7] drm/amdgpu: Add usermode queue for gfx work

[Oded Gabbay <ogabbay@kernel.org>]

On Fri, Dec 23, 2022 at 9:37 PM Shashank Sharma <shashank.sharma@amd.com> wrote:
>
> This patch adds skeleton code for usermode queue creation. It
> typically contains:
> - A new structure to keep all the user queue data in one place.
> - An IOCTL function to create/free a usermode queue.
> - A function to generate unique index for the queue.
> - A global ptr in amdgpu_dev
>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian Koenig <christian.koenig@amd.com>
> Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/Makefile           |   2 +
>  drivers/gpu/drm/amd/amdgpu/amdgpu.h           |   6 +
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h       |   1 +
>  drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 187 ++++++++++++++++++
>  .../drm/amd/include/amdgpu_usermode_queue.h   |  50 +++++
>  5 files changed, 246 insertions(+)
>  create mode 100644 drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
>  create mode 100644 drivers/gpu/drm/amd/include/amdgpu_usermode_queue.h
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
> index 6ad39cf71bdd..e2a34ee57bfb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/Makefile
> +++ b/drivers/gpu/drm/amd/amdgpu/Makefile
> @@ -209,6 +209,8 @@ amdgpu-y += \
>  # add amdkfd interfaces
>  amdgpu-y += amdgpu_amdkfd.o
>
> +# add usermode queue
> +amdgpu-y += amdgpu_userqueue.o
>
>  ifneq ($(CONFIG_HSA_AMD),)
>  AMDKFD_PATH := ../amdkfd
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 8639a4f9c6e8..4b566fcfca18 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -749,6 +749,11 @@ struct amdgpu_mqd {
>                         struct amdgpu_mqd_prop *p);
>  };
>
> +struct amdgpu_userq_globals {
> +       struct ida ida;
> +       struct mutex userq_mutex;
> +};
> +
>  #define AMDGPU_RESET_MAGIC_NUM 64
>  #define AMDGPU_MAX_DF_PERFMONS 4
>  #define AMDGPU_PRODUCT_NAME_LEN 64
> @@ -955,6 +960,7 @@ struct amdgpu_device {
>         bool                            enable_mes_kiq;
>         struct amdgpu_mes               mes;
>         struct amdgpu_mqd               mqds[AMDGPU_HW_IP_NUM];
> +       struct amdgpu_userq_globals     userq;
>
>         /* df */
>         struct amdgpu_df                df;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
> index 0fa0e56daf67..f7413859b14f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
> @@ -57,6 +57,7 @@ struct amdgpu_ctx {
>         unsigned long                   ras_counter_ce;
>         unsigned long                   ras_counter_ue;
>         uint32_t                        stable_pstate;
> +       struct amdgpu_usermode_queue    *userq;
>  };
>
>  struct amdgpu_ctx_mgr {
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> new file mode 100644
> index 000000000000..3b6e8f75495c
> --- /dev/null
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> @@ -0,0 +1,187 @@
> +/*
> + * Copyright 2022 Advanced Micro Devices, Inc.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + *
> + */
> +
> +#include "amdgpu.h"
> +#include "amdgpu_vm.h"
> +#include "amdgpu_mes.h"
> +#include "amdgpu_usermode_queue.h"
> +#include "soc15_common.h"
> +
> +#define CHECK_ACCESS(a) (access_ok((const void __user *)a, sizeof(__u64)))
> +
> +static int
> +amdgpu_userqueue_index(struct amdgpu_device *adev)
> +{
> +    int index;
> +    struct amdgpu_userq_globals *uqg = &adev->userq;
> +
> +    index = ida_simple_get(&uqg->ida, 2, AMDGPU_MAX_USERQ, GFP_KERNEL);
> +    return index;
> +}
> +
> +static void
> +amdgpu_userqueue_remove_index(struct amdgpu_device *adev, struct amdgpu_usermode_queue *queue)
> +{
> +    struct amdgpu_userq_globals *uqg = &adev->userq;
> +
> +    ida_simple_remove(&uqg->ida, queue->queue_id);
> +}
> +
> +static int
> +amdgpu_userqueue_validate_input(struct amdgpu_device *adev, struct drm_amdgpu_userq_mqd *mqd_in)
> +{
> +    if (mqd_in->queue_va == 0 || mqd_in->doorbell_handle == 0 || mqd_in->doorbell_offset == 0) {
> +        DRM_ERROR("Invalid queue object address\n");
> +        return -EINVAL;
> +    }
> +
> +    if (mqd_in->queue_size == 0 || mqd_in->rptr_va == 0 || mqd_in->wptr_va == 0) {
> +        DRM_ERROR("Invalid queue object value\n");
> +        return -EINVAL;
> +    }
> +
> +    if (mqd_in->ip_type < AMDGPU_HW_IP_GFX || mqd_in->ip_type >= AMDGPU_HW_IP_NUM) {
> +        DRM_ERROR("Invalid HW IP type 0x%x\n", mqd_in->ip_type);
> +        return -EINVAL;
> +    }
> +
> +    if (!CHECK_ACCESS(mqd_in->queue_va) || !CHECK_ACCESS(mqd_in->rptr_va) ||
> +        !CHECK_ACCESS(mqd_in->wptr_va)) {
> +            DRM_ERROR("Invalid mapping of queue ptrs, access error\n");
> +            return -EINVAL;
> +    }
> +
> +    DRM_DEBUG_DRIVER("Input parameters to create queue are valid\n");
> +    return 0;
> +}
> +
> +int amdgpu_userqueue_create(struct amdgpu_device *adev, struct drm_file *filp,
> +                            union drm_amdgpu_userq *args)
> +{
> +    int r, pasid;
> +    struct amdgpu_usermode_queue *queue;
> +    struct amdgpu_fpriv *fpriv = filp->driver_priv;
> +    struct amdgpu_vm *vm = &fpriv->vm;
> +    struct amdgpu_ctx *ctx = amdgpu_ctx_get(fpriv, args->in.ctx_id);
> +    struct drm_amdgpu_userq_mqd *mqd_in = &args->in.mqd;
> +
> +    if (!ctx) {
> +        DRM_ERROR("Invalid GPU context\n");
> +        return -EINVAL;
> +    }
> +
> +    if (vm->pasid < 0) {
> +        DRM_WARN("No PASID info found\n");
> +        pasid = 0;
> +    }
> +
> +    mutex_lock(&adev->userq.userq_mutex);
> +
> +    queue = kzalloc(sizeof(struct amdgpu_usermode_queue), GFP_KERNEL);
> +    if (!queue) {
> +        DRM_ERROR("Failed to allocate memory for queue\n");
> +        mutex_unlock(&adev->userq.userq_mutex);
> +        return -ENOMEM;
> +    }
> +
> +    r = amdgpu_userqueue_validate_input(adev, mqd_in);
> +    if (r < 0) {
> +        DRM_ERROR("Invalid input to create queue\n");
> +        goto free_queue;
> +    }
> +
> +    queue->vm = vm;
> +    queue->pasid = pasid;
> +    queue->wptr_gpu_addr = mqd_in->wptr_va;
> +    queue->rptr_gpu_addr = mqd_in->rptr_va;
> +    queue->queue_size = mqd_in->queue_size;
> +    queue->queue_type = mqd_in->ip_type;
> +    queue->paging = false;
> +    queue->flags = mqd_in->flags;
> +    queue->queue_id = amdgpu_userqueue_index(adev);
> +
> +    ctx->userq = queue;
It looks like you have a single userq per context, and here you simply
override the userq pointer.
Maybe I've missed it, but where do you protect against a user
accidentally creating two user queues ? It will cause a memory leak as
you don't release the previous q.
I would imagine you should reject the user from creating another userq
until it frees the current userq.

Oded

> +    args->out.q_id = queue->queue_id;
> +    args->out.flags = 0;
> +    mutex_unlock(&adev->userq.userq_mutex);
> +    return 0;
> +
> +free_queue:
> +    amdgpu_userqueue_remove_index(adev, queue);
> +    mutex_unlock(&adev->userq.userq_mutex);
> +    kfree(queue);
> +    return r;
> +}
> +
> +void amdgpu_userqueue_destroy(struct amdgpu_device *adev, struct drm_file *filp,
> +                              union drm_amdgpu_userq *args)
> +{
> +    struct amdgpu_fpriv *fpriv = filp->driver_priv;
> +    struct amdgpu_ctx *ctx = amdgpu_ctx_get(fpriv, args->in.ctx_id);
> +    struct amdgpu_usermode_queue *queue = ctx->userq;
> +
> +    mutex_lock(&adev->userq.userq_mutex);
> +    amdgpu_userqueue_remove_index(adev, queue);
> +    ctx->userq = NULL;
> +    mutex_unlock(&adev->userq.userq_mutex);
> +    kfree(queue);
> +}
> +
> +int amdgpu_userq_ioctl(struct drm_device *dev, void *data,
> +                      struct drm_file *filp)
> +{
> +    union drm_amdgpu_userq *args = data;
> +    struct amdgpu_device *adev = drm_to_adev(dev);
> +    int r = 0;
> +
> +    switch (args->in.op) {
> +    case AMDGPU_USERQ_OP_CREATE:
> +        r = amdgpu_userqueue_create(adev, filp, args);
> +        if (r)
> +            DRM_ERROR("Failed to create usermode queue\n");
> +        break;
> +
> +    case AMDGPU_USERQ_OP_FREE:
> +        amdgpu_userqueue_destroy(adev, filp, args);
> +        break;
> +
> +    default:
> +        DRM_ERROR("Invalid user queue op specified: %d\n", args->in.op);
> +        return -EINVAL;
> +    }
> +
> +    return r;
> +}
> +
> +int amdgpu_userqueue_init(struct amdgpu_device *adev)
> +{
> +    struct amdgpu_userq_globals *uqg = &adev->userq;
> +
> +    mutex_init(&uqg->userq_mutex);
> +    return 0;
> +}
> +
> +void amdgpu_userqueue_fini(struct amdgpu_device *adev)
> +{
> +
> +}
> diff --git a/drivers/gpu/drm/amd/include/amdgpu_usermode_queue.h b/drivers/gpu/drm/amd/include/amdgpu_usermode_queue.h
> new file mode 100644
> index 000000000000..c1fe39ffaf72
> --- /dev/null
> +++ b/drivers/gpu/drm/amd/include/amdgpu_usermode_queue.h
> @@ -0,0 +1,50 @@
> +/*
> + * Copyright 2022 Advanced Micro Devices, Inc.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + *
> + */
> +
> +#ifndef AMDGPU_USERMODE_QUEUE_H_
> +#define AMDGPU_USERMODE_QUEUE_H_
> +
> +#define AMDGPU_MAX_USERQ 512
> +
> +struct amdgpu_usermode_queue {
> +       int             queue_id;
> +       int             queue_type;
> +       int             queue_size;
> +       int             paging;
> +       int             pasid;
> +       int             use_doorbell;
> +       int             doorbell_index;
> +
> +       uint64_t        mqd_gpu_addr;
> +       uint64_t        wptr_gpu_addr;
> +       uint64_t        rptr_gpu_addr;
> +       uint64_t        queue_gpu_addr;
> +       uint64_t        flags;
> +       void            *mqd_cpu_ptr;
> +
> +       struct amdgpu_bo        *mqd_obj;
> +       struct amdgpu_vm        *vm;
> +       struct list_head        list;
> +};
> +
> +#endif
> --
> 2.34.1
>