thr3ads.net - Nouveau - [Nouveau] [PATCH 3/8] drm/amdgpu: Implement mmap as GEM object function [Apr 2021]

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Felix Kuehling

2021-Apr-06 15:27 UTC

[Nouveau] [PATCH 3/8] drm/amdgpu: Implement mmap as GEM object function

Am 2021-04-06 um 6:38 a.m. schrieb Thomas Zimmermann:> Hi
>
> Am 06.04.21 um 11:35 schrieb Christian K?nig:
>> Am 06.04.21 um 11:08 schrieb Thomas Zimmermann:
>>> Moving the driver-specific mmap code into a GEM object function
allows
>>> for using DRM helpers for various mmap callbacks.
>>>
>>> This change resolves several inconsistencies between regular mmap
and
>>> prime-based mmap. The vm_ops field in vma is now set for all
mmap'ed
>>> areas. Previously it way only set for regular mmap calls,
prime-based
>>> mmap used TTM's default vm_ops. The check for kfd_bo has been
taken
>>> from amdgpu_verify_access(), which is not called any longer and has
>>> been removed.
>>>
>>> As a side effect, amdgpu_ttm_vm_ops and amdgpu_ttm_fault() are now
>>> implemented in amdgpu's GEM code.
>>>
>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>>> ---
>>> ? drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 46 -------------
>>> ? drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h |? 2 -
>>> ? drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c???? |? 4 +-
>>> ? drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c???? | 64
+++++++++++++++++++
>>> ? drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c???? | 71
>>> ---------------------
>>> ? drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h???? |? 1 -
>>> ? 6 files changed, 66 insertions(+), 122 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>> index e0c4f7c7f1b9..19c5ab08d9ec 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>> @@ -42,52 +42,6 @@
>>> ? #include <linux/pci-p2pdma.h>
>>> ? #include <linux/pm_runtime.h>
>>> -/**
>>> - * amdgpu_gem_prime_mmap - &drm_driver.gem_prime_mmap
implementation
>>> - * @obj: GEM BO
>>> - * @vma: Virtual memory area
>>> - *
>>> - * Sets up a userspace mapping of the BO's memory in the given
>>> - * virtual memory area.
>>> - *
>>> - * Returns:
>>> - * 0 on success or a negative error code on failure.
>>> - */
>>> -int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,
>>> -????????????? struct vm_area_struct *vma)
>>> -{
>>> -??? struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
>>> -??? struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
>>> -??? unsigned asize = amdgpu_bo_size(bo);
>>> -??? int ret;
>>> -
>>> -??? if (!vma->vm_file)
>>> -??????? return -ENODEV;
>>> -
>>> -??? if (adev == NULL)
>>> -??????? return -ENODEV;
>>> -
>>> -??? /* Check for valid size. */
>>> -??? if (asize < vma->vm_end - vma->vm_start)
>>> -??????? return -EINVAL;
>>> -
>>> -??? if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm) ||
>>> -??????? (bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS)) {
>>> -??????? return -EPERM;
>>> -??? }
>>> -??? vma->vm_pgoff += amdgpu_bo_mmap_offset(bo) >>
PAGE_SHIFT;
>>> -
>>> -??? /* prime mmap does not need to check access, so allow here */
>>> -??? ret = drm_vma_node_allow(&obj->vma_node,
>>> vma->vm_file->private_data);
>>> -??? if (ret)
>>> -??????? return ret;
>>> -
>>> -??? ret = ttm_bo_mmap(vma->vm_file, vma,
&adev->mman.bdev);
>>> -??? drm_vma_node_revoke(&obj->vma_node,
vma->vm_file->private_data);
>>> -
>>> -??? return ret;
>>> -}
>>> -
>>> ? static int
>>> ? __dma_resv_make_exclusive(struct dma_resv *obj)
>>> ? {
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
>>> index 39b5b9616fd8..3e93b9b407a9 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
>>> @@ -31,8 +31,6 @@ struct drm_gem_object
>>> *amdgpu_gem_prime_import(struct drm_device *dev,
>>> ????????????????????????? struct dma_buf *dma_buf);
>>> ? bool amdgpu_dmabuf_is_xgmi_accessible(struct amdgpu_device *adev,
>>> ??????????????????????? struct amdgpu_bo *bo);
>>> -int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,
>>> -????????????? struct vm_area_struct *vma);
>>> ? extern const struct dma_buf_ops amdgpu_dmabuf_ops;
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>> index 76f48f79c70b..e96d2758f4bb 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>> @@ -1656,7 +1656,7 @@ static const struct file_operations
>>> amdgpu_driver_kms_fops = {
>>> ????? .flush = amdgpu_flush,
>>> ????? .release = drm_release,
>>> ????? .unlocked_ioctl = amdgpu_drm_ioctl,
>>> -??? .mmap = amdgpu_mmap,
>>> +??? .mmap = drm_gem_mmap,
>>> ????? .poll = drm_poll,
>>> ????? .read = drm_read,
>>> ? #ifdef CONFIG_COMPAT
>>> @@ -1719,7 +1719,7 @@ static const struct drm_driver
>>> amdgpu_kms_driver = {
>>> ????? .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
>>> ????? .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
>>> ????? .gem_prime_import = amdgpu_gem_prime_import,
>>> -??? .gem_prime_mmap = amdgpu_gem_prime_mmap,
>>> +??? .gem_prime_mmap = drm_gem_prime_mmap,
>>> ????? .name = DRIVER_NAME,
>>> ????? .desc = DRIVER_DESC,
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>> index fb7171e5507c..fe93faad05f2 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>> @@ -41,6 +41,36 @@
>>> ? static const struct drm_gem_object_funcs amdgpu_gem_object_funcs;
>>> +static vm_fault_t amdgpu_ttm_fault(struct vm_fault *vmf)
>>
>> Please name that function amdgpu_gem_fault or amdgpu_gem_object_fault
>>
>>> +{
>>> +??? struct ttm_buffer_object *bo =
vmf->vma->vm_private_data;
>>> +??? vm_fault_t ret;
>>> +
>>> +??? ret = ttm_bo_vm_reserve(bo, vmf);
>>> +??? if (ret)
>>> +??????? return ret;
>>> +
>>> +??? ret = amdgpu_bo_fault_reserve_notify(bo);
>>> +??? if (ret)
>>> +??????? goto unlock;
>>> +
>>> +??? ret = ttm_bo_vm_fault_reserved(vmf,
vmf->vma->vm_page_prot,
>>> +?????????????????????? TTM_BO_VM_NUM_PREFAULT, 1);
>>> +??? if (ret == VM_FAULT_RETRY && !(vmf->flags &
>>> FAULT_FLAG_RETRY_NOWAIT))
>>> +??????? return ret;
>>> +
>>> +unlock:
>>> +??? dma_resv_unlock(bo->base.resv);
>>> +??? return ret;
>>> +}
>>> +
>>> +static const struct vm_operations_struct amdgpu_ttm_vm_ops = {
>>> +??? .fault = amdgpu_ttm_fault,
>>> +??? .open = ttm_bo_vm_open,
>>> +??? .close = ttm_bo_vm_close,
>>> +??? .access = ttm_bo_vm_access
>>> +};
>>> +
>>> ? static void amdgpu_gem_object_free(struct drm_gem_object *gobj)
>>> ? {
>>> ????? struct amdgpu_bo *robj = gem_to_amdgpu_bo(gobj);
>>> @@ -201,6 +231,38 @@ static void amdgpu_gem_object_close(struct
>>> drm_gem_object *obj,
>>> ????? ttm_eu_backoff_reservation(&ticket, &list);
>>> ? }
>>> +static int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,
struct
>>> vm_area_struct *vma)
>>> +{
>>> +??? struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
>>> +??? struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
>>> +??? unsigned long asize = amdgpu_bo_size(bo);
>>> +
>>> +??? if (!vma->vm_file)
>>> +??????? return -ENODEV;
>>> +
>>> +??? if (!adev)
>>> +??????? return -ENODEV;
>>> +
>>> +??? /* Check for valid size. */
>>> +??? if (asize < vma->vm_end - vma->vm_start)
>>> +??????? return -EINVAL;
>>
>>> +
>>> +??? /*
>>> +???? * Don't verify access for KFD BOs. They don't have a
GEM
>>> +???? * object associated with them.
>>> +???? */
>>> +??? if (bo->kfd_bo)
>>> +??????? goto out;
>>
>> Who does the access verification now?
>
> This is somewhat confusing.
>
> I took this check as-is, including the comment, from amdgpu's
> verify_access function. The verify_access function was called by
> ttm_bo_mmap. It returned 0 and ttm_bo_mmap did the mapping.
This is probably a left-over from when we mapped BOs using /dev/kfd. We
changed this to use /dev/dri/renderD* a long time ago to fix CPU mapping
invalidations on memory evictions. I think we can let GEM do the access
check.

Regards,
? Felix

>
>>
>> Christian.
>>
>>> +
>>> +??? if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm) ||
>>> +??????? (bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS)) {
>>> +??????? return -EPERM;
>>> +??? }
>>> +
>>> +out:
>>> +??? return drm_gem_ttm_mmap(obj, vma);
>>> +}
>>> +
>>> ? static const struct drm_gem_object_funcs amdgpu_gem_object_funcs
= {
>>> ????? .free = amdgpu_gem_object_free,
>>> ????? .open = amdgpu_gem_object_open,
>>> @@ -208,6 +270,8 @@ static const struct drm_gem_object_funcs
>>> amdgpu_gem_object_funcs = {
>>> ????? .export = amdgpu_gem_prime_export,
>>> ????? .vmap = drm_gem_ttm_vmap,
>>> ????? .vunmap = drm_gem_ttm_vunmap,
>>> +??? .mmap = amdgpu_gem_prime_mmap,
>>> +??? .vm_ops = &amdgpu_ttm_vm_ops,
>>> ? };
>>> ? /*
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> index 1c6131489a85..d9de91a517c6 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> @@ -152,32 +152,6 @@ static void amdgpu_evict_flags(struct
>>> ttm_buffer_object *bo,
>>> ????? *placement = abo->placement;
>>> ? }
>>> -/**
>>> - * amdgpu_verify_access - Verify access for a mmap call
>>> - *
>>> - * @bo:??? The buffer object to map
>>> - * @filp: The file pointer from the process performing the mmap
>>> - *
>>> - * This is called by ttm_bo_mmap() to verify whether a process
>>> - * has the right to mmap a BO to their process space.
>>> - */
>>> -static int amdgpu_verify_access(struct ttm_buffer_object *bo,
>>> struct file *filp)
>>> -{
>>> -??? struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
>>> -
>>> -??? /*
>>> -???? * Don't verify access for KFD BOs. They don't have a
GEM
>>> -???? * object associated with them.
>>> -???? */
>>> -??? if (abo->kfd_bo)
>>> -??????? return 0;
>>> -
>>> -??? if (amdgpu_ttm_tt_get_usermm(bo->ttm))
>>> -??????? return -EPERM;
>>> -??? return
drm_vma_node_verify_access(&abo->tbo.base.vma_node,
>>> -????????????????????? filp->private_data);
>>> -}
>
> Here's the orignal verification code. It gives a free pass to KFD.
>
>>> -
>>> ? /**
>>> ?? * amdgpu_ttm_map_buffer - Map memory into the GART windows
>>> ?? * @bo: buffer object to map
>>> @@ -1531,7 +1505,6 @@ static struct ttm_device_funcs
>>> amdgpu_bo_driver = {
>>> ????? .eviction_valuable = amdgpu_ttm_bo_eviction_valuable,
>>> ????? .evict_flags = &amdgpu_evict_flags,
>>> ????? .move = &amdgpu_bo_move,
>>> -??? .verify_access = &amdgpu_verify_access,
>>> ????? .delete_mem_notify = &amdgpu_bo_delete_mem_notify,
>>> ????? .release_notify = &amdgpu_bo_release_notify,
>>> ????? .io_mem_reserve = &amdgpu_ttm_io_mem_reserve,
>>> @@ -1906,50 +1879,6 @@ void
>>> amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool
>>> enable)
>>> ????? adev->mman.buffer_funcs_enabled = enable;
>>> ? }
>>> -static vm_fault_t amdgpu_ttm_fault(struct vm_fault *vmf)
>>> -{
>>> -??? struct ttm_buffer_object *bo =
vmf->vma->vm_private_data;
>>> -??? vm_fault_t ret;
>>> -
>>> -??? ret = ttm_bo_vm_reserve(bo, vmf);
>>> -??? if (ret)
>>> -??????? return ret;
>>> -
>>> -??? ret = amdgpu_bo_fault_reserve_notify(bo);
>>> -??? if (ret)
>>> -??????? goto unlock;
>>> -
>>> -??? ret = ttm_bo_vm_fault_reserved(vmf,
vmf->vma->vm_page_prot,
>>> -?????????????????????? TTM_BO_VM_NUM_PREFAULT, 1);
>>> -??? if (ret == VM_FAULT_RETRY && !(vmf->flags &
>>> FAULT_FLAG_RETRY_NOWAIT))
>>> -??????? return ret;
>>> -
>>> -unlock:
>>> -??? dma_resv_unlock(bo->base.resv);
>>> -??? return ret;
>>> -}
>>> -
>>> -static const struct vm_operations_struct amdgpu_ttm_vm_ops = {
>>> -??? .fault = amdgpu_ttm_fault,
>>> -??? .open = ttm_bo_vm_open,
>>> -??? .close = ttm_bo_vm_close,
>>> -??? .access = ttm_bo_vm_access
>>> -};
>>> -
>>> -int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma)
>>> -{
>>> -??? struct drm_file *file_priv = filp->private_data;
>>> -??? struct amdgpu_device *adev =
drm_to_adev(file_priv->minor->dev);
>>> -??? int r;
>>> -
>>> -??? r = ttm_bo_mmap(filp, vma, &adev->mman.bdev);
>>> -??? if (unlikely(r != 0))
>>> -??????? return r;
>>> -
>>> -??? vma->vm_ops = &amdgpu_ttm_vm_ops;
>>> -??? return 0;
>>> -}
>
> And this was the mmap callback in struct file_operations. It calls
> ttm_bo_mmap(), which skips verification for KFD BOs. To the best of my
> knowledge, there was no additional verification for these KFD BOs.
>
> The original code in amdgpu_gem_prime_mmap() did seom verification,
> but didn't handle KFD specially. I guess, PRIME needs GEM and KFD BOs
> wouldn't quailify.
>
> In the end I went with the semantics I found in amdgpu_mmap() and
> handled KFD specially. Let me know if this requires to be changed.
>
> Best regards
> Thomas
>
>>> -
>>> ? int amdgpu_copy_buffer(struct amdgpu_ring *ring, uint64_t
src_offset,
>>> ???????????????? uint64_t dst_offset, uint32_t byte_count,
>>> ???????????????? struct dma_resv *resv,
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> index dec0db8b0b13..6e51faad7371 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> @@ -146,7 +146,6 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
>>> ????????????? struct dma_resv *resv,
>>> ????????????? struct dma_fence **fence);
>>> -int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma);
>>> ? int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo);
>>> ? int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo);
>>> ? uint64_t amdgpu_ttm_domain_start(struct amdgpu_device *adev,
>>> uint32_t type);
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>

Christian König

2021-Apr-07 11:25 UTC

head link

[Nouveau] [PATCH 3/8] drm/amdgpu: Implement mmap as GEM object function

Hi,

Am 06.04.21 um 17:27 schrieb Felix Kuehling:> Am 2021-04-06 um 6:38 a.m. schrieb Thomas Zimmermann:
>> Hi
>>
>> Am 06.04.21 um 11:35 schrieb Christian K?nig:
>>> Am 06.04.21 um 11:08 schrieb Thomas Zimmermann:
>>>> Moving the driver-specific mmap code into a GEM object function
allows
>>>> for using DRM helpers for various mmap callbacks.
>>>>
>>>> This change resolves several inconsistencies between regular
mmap and
>>>> prime-based mmap. The vm_ops field in vma is now set for all
mmap'ed
>>>> areas. Previously it way only set for regular mmap calls,
prime-based
>>>> mmap used TTM's default vm_ops. The check for kfd_bo has
been taken
>>>> from amdgpu_verify_access(), which is not called any longer and
has
>>>> been removed.
>>>>
>>>> As a side effect, amdgpu_ttm_vm_ops and amdgpu_ttm_fault() are
now
>>>> implemented in amdgpu's GEM code.
>>>>
>>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>>>> ---
>>>>  ? drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 46
-------------
>>>>  ? drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h |? 2 -
>>>>  ? drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c???? |? 4 +-
>>>>  ? drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c???? | 64
+++++++++++++++++++
>>>>  ? drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c???? | 71
>>>> ---------------------
>>>>  ? drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h???? |? 1 -
>>>>  ? 6 files changed, 66 insertions(+), 122 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>>> index e0c4f7c7f1b9..19c5ab08d9ec 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
>>>> @@ -42,52 +42,6 @@
>>>>  ? #include <linux/pci-p2pdma.h>
>>>>  ? #include <linux/pm_runtime.h>
>>>> -/**
>>>> - * amdgpu_gem_prime_mmap - &drm_driver.gem_prime_mmap
implementation
>>>> - * @obj: GEM BO
>>>> - * @vma: Virtual memory area
>>>> - *
>>>> - * Sets up a userspace mapping of the BO's memory in the
given
>>>> - * virtual memory area.
>>>> - *
>>>> - * Returns:
>>>> - * 0 on success or a negative error code on failure.
>>>> - */
>>>> -int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,
>>>> -????????????? struct vm_area_struct *vma)
>>>> -{
>>>> -??? struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
>>>> -??? struct amdgpu_device *adev =
amdgpu_ttm_adev(bo->tbo.bdev);
>>>> -??? unsigned asize = amdgpu_bo_size(bo);
>>>> -??? int ret;
>>>> -
>>>> -??? if (!vma->vm_file)
>>>> -??????? return -ENODEV;
>>>> -
>>>> -??? if (adev == NULL)
>>>> -??????? return -ENODEV;
>>>> -
>>>> -??? /* Check for valid size. */
>>>> -??? if (asize < vma->vm_end - vma->vm_start)
>>>> -??????? return -EINVAL;
>>>> -
>>>> -??? if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm) ||
>>>> -??????? (bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS))
{
>>>> -??????? return -EPERM;
>>>> -??? }
>>>> -??? vma->vm_pgoff += amdgpu_bo_mmap_offset(bo) >>
PAGE_SHIFT;
>>>> -
>>>> -??? /* prime mmap does not need to check access, so allow here
*/
>>>> -??? ret = drm_vma_node_allow(&obj->vma_node,
>>>> vma->vm_file->private_data);
>>>> -??? if (ret)
>>>> -??????? return ret;
>>>> -
>>>> -??? ret = ttm_bo_mmap(vma->vm_file, vma,
&adev->mman.bdev);
>>>> -??? drm_vma_node_revoke(&obj->vma_node,
vma->vm_file->private_data);
>>>> -
>>>> -??? return ret;
>>>> -}
>>>> -
>>>>  ? static int
>>>>  ? __dma_resv_make_exclusive(struct dma_resv *obj)
>>>>  ? {
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
>>>> index 39b5b9616fd8..3e93b9b407a9 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
>>>> @@ -31,8 +31,6 @@ struct drm_gem_object
>>>> *amdgpu_gem_prime_import(struct drm_device *dev,
>>>>  ????????????????????????? struct dma_buf *dma_buf);
>>>>  ? bool amdgpu_dmabuf_is_xgmi_accessible(struct amdgpu_device
*adev,
>>>>  ??????????????????????? struct amdgpu_bo *bo);
>>>> -int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,
>>>> -????????????? struct vm_area_struct *vma);
>>>>  ? extern const struct dma_buf_ops amdgpu_dmabuf_ops;
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>>> index 76f48f79c70b..e96d2758f4bb 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
>>>> @@ -1656,7 +1656,7 @@ static const struct file_operations
>>>> amdgpu_driver_kms_fops = {
>>>>  ????? .flush = amdgpu_flush,
>>>>  ????? .release = drm_release,
>>>>  ????? .unlocked_ioctl = amdgpu_drm_ioctl,
>>>> -??? .mmap = amdgpu_mmap,
>>>> +??? .mmap = drm_gem_mmap,
>>>>  ????? .poll = drm_poll,
>>>>  ????? .read = drm_read,
>>>>  ? #ifdef CONFIG_COMPAT
>>>> @@ -1719,7 +1719,7 @@ static const struct drm_driver
>>>> amdgpu_kms_driver = {
>>>>  ????? .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
>>>>  ????? .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
>>>>  ????? .gem_prime_import = amdgpu_gem_prime_import,
>>>> -??? .gem_prime_mmap = amdgpu_gem_prime_mmap,
>>>> +??? .gem_prime_mmap = drm_gem_prime_mmap,
>>>>  ????? .name = DRIVER_NAME,
>>>>  ????? .desc = DRIVER_DESC,
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>> index fb7171e5507c..fe93faad05f2 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>> @@ -41,6 +41,36 @@
>>>>  ? static const struct drm_gem_object_funcs
amdgpu_gem_object_funcs;
>>>> +static vm_fault_t amdgpu_ttm_fault(struct vm_fault *vmf)
>>> Please name that function amdgpu_gem_fault or
amdgpu_gem_object_fault
>>>
>>>> +{
>>>> +??? struct ttm_buffer_object *bo =
vmf->vma->vm_private_data;
>>>> +??? vm_fault_t ret;
>>>> +
>>>> +??? ret = ttm_bo_vm_reserve(bo, vmf);
>>>> +??? if (ret)
>>>> +??????? return ret;
>>>> +
>>>> +??? ret = amdgpu_bo_fault_reserve_notify(bo);
>>>> +??? if (ret)
>>>> +??????? goto unlock;
>>>> +
>>>> +??? ret = ttm_bo_vm_fault_reserved(vmf,
vmf->vma->vm_page_prot,
>>>> +?????????????????????? TTM_BO_VM_NUM_PREFAULT, 1);
>>>> +??? if (ret == VM_FAULT_RETRY && !(vmf->flags &
>>>> FAULT_FLAG_RETRY_NOWAIT))
>>>> +??????? return ret;
>>>> +
>>>> +unlock:
>>>> +??? dma_resv_unlock(bo->base.resv);
>>>> +??? return ret;
>>>> +}
>>>> +
>>>> +static const struct vm_operations_struct amdgpu_ttm_vm_ops = {
>>>> +??? .fault = amdgpu_ttm_fault,
>>>> +??? .open = ttm_bo_vm_open,
>>>> +??? .close = ttm_bo_vm_close,
>>>> +??? .access = ttm_bo_vm_access
>>>> +};
>>>> +
>>>>  ? static void amdgpu_gem_object_free(struct drm_gem_object
*gobj)
>>>>  ? {
>>>>  ????? struct amdgpu_bo *robj = gem_to_amdgpu_bo(gobj);
>>>> @@ -201,6 +231,38 @@ static void amdgpu_gem_object_close(struct
>>>> drm_gem_object *obj,
>>>>  ????? ttm_eu_backoff_reservation(&ticket, &list);
>>>>  ? }
>>>> +static int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,
struct
>>>> vm_area_struct *vma)
>>>> +{
>>>> +??? struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
>>>> +??? struct amdgpu_device *adev =
amdgpu_ttm_adev(bo->tbo.bdev);
>>>> +??? unsigned long asize = amdgpu_bo_size(bo);
>>>> +
>>>> +??? if (!vma->vm_file)
>>>> +??????? return -ENODEV;
>>>> +
>>>> +??? if (!adev)
>>>> +??????? return -ENODEV;
>>>> +
>>>> +??? /* Check for valid size. */
>>>> +??? if (asize < vma->vm_end - vma->vm_start)
>>>> +??????? return -EINVAL;
>>>> +
>>>> +??? /*
>>>> +???? * Don't verify access for KFD BOs. They don't
have a GEM
>>>> +???? * object associated with them.
>>>> +???? */
>>>> +??? if (bo->kfd_bo)
>>>> +??????? goto out;
>>> Who does the access verification now?
>> This is somewhat confusing.
>>
>> I took this check as-is, including the comment, from amdgpu's
>> verify_access function. The verify_access function was called by
>> ttm_bo_mmap. It returned 0 and ttm_bo_mmap did the mapping.
> This is probably a left-over from when we mapped BOs using /dev/kfd. We
> changed this to use /dev/dri/renderD* a long time ago to fix CPU mapping
> invalidations on memory evictions. I think we can let GEM do the access
> check.
Ok, good to know.

Thomas can you remove the extra handling in a separate prerequisite patch?

If anybody then bisects to this patch we at least know what to do to get 
it working again.

Regards,
Christian.
>
> Regards,
>  ? Felix
>
>
>>> Christian.
>>>
>>>> +
>>>> +??? if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm) ||
>>>> +??????? (bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS))
{
>>>> +??????? return -EPERM;
>>>> +??? }
>>>> +
>>>> +out:
>>>> +??? return drm_gem_ttm_mmap(obj, vma);
>>>> +}
>>>> +
>>>>  ? static const struct drm_gem_object_funcs
amdgpu_gem_object_funcs = {
>>>>  ????? .free = amdgpu_gem_object_free,
>>>>  ????? .open = amdgpu_gem_object_open,
>>>> @@ -208,6 +270,8 @@ static const struct drm_gem_object_funcs
>>>> amdgpu_gem_object_funcs = {
>>>>  ????? .export = amdgpu_gem_prime_export,
>>>>  ????? .vmap = drm_gem_ttm_vmap,
>>>>  ????? .vunmap = drm_gem_ttm_vunmap,
>>>> +??? .mmap = amdgpu_gem_prime_mmap,
>>>> +??? .vm_ops = &amdgpu_ttm_vm_ops,
>>>>  ? };
>>>>  ? /*
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>> index 1c6131489a85..d9de91a517c6 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>> @@ -152,32 +152,6 @@ static void amdgpu_evict_flags(struct
>>>> ttm_buffer_object *bo,
>>>>  ????? *placement = abo->placement;
>>>>  ? }
>>>> -/**
>>>> - * amdgpu_verify_access - Verify access for a mmap call
>>>> - *
>>>> - * @bo:??? The buffer object to map
>>>> - * @filp: The file pointer from the process performing the
mmap
>>>> - *
>>>> - * This is called by ttm_bo_mmap() to verify whether a process
>>>> - * has the right to mmap a BO to their process space.
>>>> - */
>>>> -static int amdgpu_verify_access(struct ttm_buffer_object *bo,
>>>> struct file *filp)
>>>> -{
>>>> -??? struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
>>>> -
>>>> -??? /*
>>>> -???? * Don't verify access for KFD BOs. They don't
have a GEM
>>>> -???? * object associated with them.
>>>> -???? */
>>>> -??? if (abo->kfd_bo)
>>>> -??????? return 0;
>>>> -
>>>> -??? if (amdgpu_ttm_tt_get_usermm(bo->ttm))
>>>> -??????? return -EPERM;
>>>> -??? return
drm_vma_node_verify_access(&abo->tbo.base.vma_node,
>>>> -????????????????????? filp->private_data);
>>>> -}
>> Here's the orignal verification code. It gives a free pass to KFD.
>>
>>>> -
>>>>  ? /**
>>>>  ?? * amdgpu_ttm_map_buffer - Map memory into the GART windows
>>>>  ?? * @bo: buffer object to map
>>>> @@ -1531,7 +1505,6 @@ static struct ttm_device_funcs
>>>> amdgpu_bo_driver = {
>>>>  ????? .eviction_valuable = amdgpu_ttm_bo_eviction_valuable,
>>>>  ????? .evict_flags = &amdgpu_evict_flags,
>>>>  ????? .move = &amdgpu_bo_move,
>>>> -??? .verify_access = &amdgpu_verify_access,
>>>>  ????? .delete_mem_notify = &amdgpu_bo_delete_mem_notify,
>>>>  ????? .release_notify = &amdgpu_bo_release_notify,
>>>>  ????? .io_mem_reserve = &amdgpu_ttm_io_mem_reserve,
>>>> @@ -1906,50 +1879,6 @@ void
>>>> amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev,
bool
>>>> enable)
>>>>  ????? adev->mman.buffer_funcs_enabled = enable;
>>>>  ? }
>>>> -static vm_fault_t amdgpu_ttm_fault(struct vm_fault *vmf)
>>>> -{
>>>> -??? struct ttm_buffer_object *bo =
vmf->vma->vm_private_data;
>>>> -??? vm_fault_t ret;
>>>> -
>>>> -??? ret = ttm_bo_vm_reserve(bo, vmf);
>>>> -??? if (ret)
>>>> -??????? return ret;
>>>> -
>>>> -??? ret = amdgpu_bo_fault_reserve_notify(bo);
>>>> -??? if (ret)
>>>> -??????? goto unlock;
>>>> -
>>>> -??? ret = ttm_bo_vm_fault_reserved(vmf,
vmf->vma->vm_page_prot,
>>>> -?????????????????????? TTM_BO_VM_NUM_PREFAULT, 1);
>>>> -??? if (ret == VM_FAULT_RETRY && !(vmf->flags &
>>>> FAULT_FLAG_RETRY_NOWAIT))
>>>> -??????? return ret;
>>>> -
>>>> -unlock:
>>>> -??? dma_resv_unlock(bo->base.resv);
>>>> -??? return ret;
>>>> -}
>>>> -
>>>> -static const struct vm_operations_struct amdgpu_ttm_vm_ops = {
>>>> -??? .fault = amdgpu_ttm_fault,
>>>> -??? .open = ttm_bo_vm_open,
>>>> -??? .close = ttm_bo_vm_close,
>>>> -??? .access = ttm_bo_vm_access
>>>> -};
>>>> -
>>>> -int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma)
>>>> -{
>>>> -??? struct drm_file *file_priv = filp->private_data;
>>>> -??? struct amdgpu_device *adev =
drm_to_adev(file_priv->minor->dev);
>>>> -??? int r;
>>>> -
>>>> -??? r = ttm_bo_mmap(filp, vma, &adev->mman.bdev);
>>>> -??? if (unlikely(r != 0))
>>>> -??????? return r;
>>>> -
>>>> -??? vma->vm_ops = &amdgpu_ttm_vm_ops;
>>>> -??? return 0;
>>>> -}
>> And this was the mmap callback in struct file_operations. It calls
>> ttm_bo_mmap(), which skips verification for KFD BOs. To the best of my
>> knowledge, there was no additional verification for these KFD BOs.
>>
>> The original code in amdgpu_gem_prime_mmap() did seom verification,
>> but didn't handle KFD specially. I guess, PRIME needs GEM and KFD
BOs
>> wouldn't quailify.
>>
>> In the end I went with the semantics I found in amdgpu_mmap() and
>> handled KFD specially. Let me know if this requires to be changed.
>>
>> Best regards
>> Thomas
>>
>>>> -
>>>>  ? int amdgpu_copy_buffer(struct amdgpu_ring *ring, uint64_t
src_offset,
>>>>  ???????????????? uint64_t dst_offset, uint32_t byte_count,
>>>>  ???????????????? struct dma_resv *resv,
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>> index dec0db8b0b13..6e51faad7371 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>> @@ -146,7 +146,6 @@ int amdgpu_fill_buffer(struct amdgpu_bo
*bo,
>>>>  ????????????? struct dma_resv *resv,
>>>>  ????????????? struct dma_fence **fence);
>>>> -int amdgpu_mmap(struct file *filp, struct vm_area_struct
*vma);
>>>>  ? int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo);
>>>>  ? int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo);
>>>>  ? uint64_t amdgpu_ttm_domain_start(struct amdgpu_device *adev,
>>>> uint32_t type);
>>> _______________________________________________
>>> dri-devel mailing list
>>> dri-devel at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel

Nouveau - Apr 2021 - [PATCH 3/8] drm/amdgpu: Implement mmap as GEM object function

[Nouveau] [PATCH 3/8] drm/amdgpu: Implement mmap as GEM object function

[Nouveau] [PATCH 3/8] drm/amdgpu: Implement mmap as GEM object function