Am 2021-04-06 um 6:38 a.m. schrieb Thomas Zimmermann: > Hi > > Am 06.04.21 um 11:35 schrieb Christian König: >> 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 <tzimmerm...@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-de...@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/dri-devel > _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx