Christian König
2021-Apr-07 11:25 UTC
[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
Felix Kuehling
2021-Apr-07 19:34 UTC
[Nouveau] [PATCH 3/8] drm/amdgpu: Implement mmap as GEM object function
On 2021-04-07 7:25 a.m., Christian K?nig wrote:>>>>> +??? /* >>>>> +???? * 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.FWIW, I ran KFDTest test with this shortcut removed on current amd-staging-drm-next + my HMM patch series, and it didn't seem to cause any issues. Regards, ? Felix> > Regards, > Christian.