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Re: [PATCH v3 27/28] drm/amdgpu: get rid of amdgpu_ttm_clear_buffer

by Christian König

On 11/21/25 11:12, Pierre-Eric Pelloux-Prayer wrote: > It's doing the same thing as amdgpu_fill_buffer(src_data=0), so drop it. > > The only caveat is that amdgpu_res_cleared() return value is only valid > right after allocation. > > --- > v2: introduce new "bool consider_clear_status" arg > --- > > Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer(a)amd.com> It would be better to have that ealier in the patch set, but I guess that gives you rebasing problems? Christian. > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 16 ++-- > drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 90 +++++----------------- > drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 7 +- > 3 files changed, 33 insertions(+), 80 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c > index 7d8d70135cc2..dccc31d0128e 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c > @@ -725,13 +725,17 @@ int amdgpu_bo_create(struct amdgpu_device *adev, > bo->tbo.resource->mem_type == TTM_PL_VRAM) { > struct dma_fence *fence; > > - r = amdgpu_ttm_clear_buffer(adev, bo, bo->tbo.base.resv, &fence); > + r = amdgpu_fill_buffer(adev, amdgpu_ttm_next_clear_entity(adev), > + bo, 0, NULL, &fence, > + true, AMDGPU_KERNEL_JOB_ID_TTM_CLEAR_BUFFER); > if (unlikely(r)) > goto fail_unreserve; > > - dma_resv_add_fence(bo->tbo.base.resv, fence, > - DMA_RESV_USAGE_KERNEL); > - dma_fence_put(fence); > + if (fence) { > + dma_resv_add_fence(bo->tbo.base.resv, fence, > + DMA_RESV_USAGE_KERNEL); > + dma_fence_put(fence); > + } > } > if (!bp->resv) > amdgpu_bo_unreserve(bo); > @@ -1323,8 +1327,8 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo) > goto out; > > r = amdgpu_fill_buffer(adev, amdgpu_ttm_next_clear_entity(adev), > - abo, 0, &bo->base._resv, > - &fence, AMDGPU_KERNEL_JOB_ID_CLEAR_ON_RELEASE); > + abo, 0, &bo->base._resv, &fence, > + false, AMDGPU_KERNEL_JOB_ID_CLEAR_ON_RELEASE); > if (WARN_ON(r)) > goto out; > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > index 39cfe2dbdf03..c65c411ce26e 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > @@ -459,7 +459,7 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo, > > r = amdgpu_fill_buffer(adev, entity, > abo, 0, NULL, &wipe_fence, > - AMDGPU_KERNEL_JOB_ID_MOVE_BLIT); > + false, AMDGPU_KERNEL_JOB_ID_MOVE_BLIT); > if (r) { > goto error; > } else if (wipe_fence) { > @@ -2459,79 +2459,28 @@ static int amdgpu_ttm_fill_mem(struct amdgpu_device *adev, > } > > /** > - * amdgpu_ttm_clear_buffer - clear memory buffers > + * amdgpu_fill_buffer - fill a buffer with a given value > * @adev: amdgpu device object > - * @bo: amdgpu buffer object > - * @resv: reservation object > - * @fence: dma_fence associated with the operation > + * @entity: optional entity to use. If NULL, the clearing entities will be > + * used to load-balance the partial clears > + * @bo: the bo to fill > + * @src_data: the value to set > + * @resv: fences contained in this reservation will be used as dependencies. > + * @out_fence: the fence from the last clear will be stored here. It might be > + * NULL if no job was run. > + * @dependency: optional input dependency fence. > + * @consider_clear_status: true if region reported as cleared by amdgpu_res_cleared() > + * are skipped. > + * @k_job_id: trace id > * > - * Clear the memory buffer resource. > - * > - * Returns: > - * 0 for success or a negative error code on failure. > */ > -int amdgpu_ttm_clear_buffer(struct amdgpu_device *adev, > - struct amdgpu_bo *bo, > - struct dma_resv *resv, > - struct dma_fence **fence) > -{ > - struct amdgpu_ttm_buffer_entity *entity; > - struct amdgpu_res_cursor cursor; > - u64 addr; > - int r = 0; > - > - if (!adev->mman.buffer_funcs_enabled) > - return -EINVAL; > - > - if (!fence) > - return -EINVAL; > - entity = &adev->mman.clear_entities[0]; > - *fence = dma_fence_get_stub(); > - > - amdgpu_res_first(bo->tbo.resource, 0, amdgpu_bo_size(bo), &cursor); > - > - mutex_lock(&entity->lock); > - while (cursor.remaining) { > - struct dma_fence *next = NULL; > - u64 size; > - > - if (amdgpu_res_cleared(&cursor)) { > - amdgpu_res_next(&cursor, cursor.size); > - continue; > - } > - > - /* Never clear more than 256MiB at once to avoid timeouts */ > - size = min(cursor.size, 256ULL << 20); > - > - r = amdgpu_ttm_map_buffer(adev, entity, > - &bo->tbo, bo->tbo.resource, &cursor, > - 1, false, false, &size, &addr); > - if (r) > - goto err; > - > - r = amdgpu_ttm_fill_mem(adev, entity, 0, addr, size, resv, > - &next, true, > - AMDGPU_KERNEL_JOB_ID_TTM_CLEAR_BUFFER); > - if (r) > - goto err; > - > - dma_fence_put(*fence); > - *fence = next; > - > - amdgpu_res_next(&cursor, size); > - } > -err: > - mutex_unlock(&entity->lock); > - > - return r; > -} > - > int amdgpu_fill_buffer(struct amdgpu_device *adev, > struct amdgpu_ttm_buffer_entity *entity, > struct amdgpu_bo *bo, > uint32_t src_data, > struct dma_resv *resv, > - struct dma_fence **f, > + struct dma_fence **out_fence, > + bool consider_clear_status, > u64 k_job_id) > { > struct dma_fence *fence = NULL; > @@ -2551,6 +2500,11 @@ int amdgpu_fill_buffer(struct amdgpu_device *adev, > struct dma_fence *next; > uint64_t cur_size, to; > > + if (consider_clear_status && amdgpu_res_cleared(&dst)) { > + amdgpu_res_next(&dst, dst.size); > + continue; > + } > + > /* Never fill more than 256MiB at once to avoid timeouts */ > cur_size = min(dst.size, 256ULL << 20); > > @@ -2574,9 +2528,7 @@ int amdgpu_fill_buffer(struct amdgpu_device *adev, > } > error: > mutex_unlock(&entity->lock); > - if (f) > - *f = dma_fence_get(fence); > - dma_fence_put(fence); > + *out_fence = fence; > return r; > } > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h > index 653a4d17543e..f3bdbcec9afc 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h > @@ -181,16 +181,13 @@ int amdgpu_copy_buffer(struct amdgpu_device *adev, > struct dma_resv *resv, > struct dma_fence **fence, > bool vm_needs_flush, uint32_t copy_flags); > -int amdgpu_ttm_clear_buffer(struct amdgpu_device *adev, > - struct amdgpu_bo *bo, > - struct dma_resv *resv, > - struct dma_fence **fence); > int amdgpu_fill_buffer(struct amdgpu_device *adev, > struct amdgpu_ttm_buffer_entity *entity, > struct amdgpu_bo *bo, > uint32_t src_data, > struct dma_resv *resv, > - struct dma_fence **f, > + struct dma_fence **out_fence, > + bool consider_clear_status, > u64 k_job_id); > struct amdgpu_ttm_buffer_entity *amdgpu_ttm_next_clear_entity(struct amdgpu_device *adev); >

11 hours, 58 minutes

[PATCH v2 0/9] Initial DMABUF support for iommufd

by Jason Gunthorpe

This series is the start of adding full DMABUF support to iommufd. Currently it is limited to only work with VFIO's DMABUF exporter. It sits on top of Leon's series to add a DMABUF exporter to VFIO: https://lore.kernel.org/all/20251120-dmabuf-vfio-v9-0-d7f71607f371@nvidia.c… The existing IOMMU_IOAS_MAP_FILE is enhanced to detect DMABUF fd's, but otherwise works the same as it does today for a memfd. The user can select a slice of the FD to map into the ioas and if the underliyng alignment requirements are met it will be placed in the iommu_domain. Though limited, it is enough to allow a VMM like QEMU to connect MMIO BAR memory from VFIO to an iommu_domain controlled by iommufd. This is used for PCI Peer to Peer support in VMs, and is the last feature that the VFIO type 1 container has that iommufd couldn't do. The VFIO type1 version extracts raw PFNs from VMAs, which has no lifetime control and is a use-after-free security problem. Instead iommufd relies on revokable DMABUFs. Whenever VFIO thinks there should be no access to the MMIO it can shoot down the mapping in iommufd which will unmap it from the iommu_domain. There is no automatic remap, this is a safety protocol so the kernel doesn't get stuck. Userspace is expected to know it is doing something that will revoke the dmabuf and map/unmap it around the activity. Eg when QEMU goes to issue FLR it should do the map/unmap to iommufd. Since DMABUF is missing some key general features for this use case it relies on a "private interconnect" between VFIO and iommufd via the vfio_pci_dma_buf_iommufd_map() call. The call confirms the DMABUF has revoke semantics and delivers a phys_addr for the memory suitable for use with iommu_map(). Medium term there is a desire to expand the supported DMABUFs to include GPU drivers to support DPDK/SPDK type use cases so future series will work to add a general concept of revoke and a general negotiation of interconnect to remove vfio_pci_dma_buf_iommufd_map(). I also plan another series to modify iommufd's vfio_compat to transparently pull a dmabuf out of a VFIO VMA to emulate more of the uAPI of type1. The latest series for interconnect negotation to exchange a phys_addr is: https://lore.kernel.org/r/20251027044712.1676175-1-vivek.kasireddy@intel.com And the discussion for design of revoke is here: https://lore.kernel.org/dri-devel/20250114173103.GE5556@nvidia.com/ This is on github: https://github.com/jgunthorpe/linux/commits/iommufd_dmabuf v2: - Rebase on Leon's v9 - Fix mislocking in an iopt_fill_domain() error path - Revise the comments around how the sub page offset works - Remove a useless WARN_ON in iopt_pages_rw_access() - Fixed missed memory free in the selftest v1: https://patch.msgid.link/r/0-v1-64bed2430cdb+31b-iommufd_dmabuf_jgg@nvidia.… Jason Gunthorpe (9): vfio/pci: Add vfio_pci_dma_buf_iommufd_map() iommufd: Add DMABUF to iopt_pages iommufd: Do not map/unmap revoked DMABUFs iommufd: Allow a DMABUF to be revoked iommufd: Allow MMIO pages in a batch iommufd: Have pfn_reader process DMABUF iopt_pages iommufd: Have iopt_map_file_pages convert the fd to a file iommufd: Accept a DMABUF through IOMMU_IOAS_MAP_FILE iommufd/selftest: Add some tests for the dmabuf flow drivers/iommu/iommufd/io_pagetable.c | 78 +++- drivers/iommu/iommufd/io_pagetable.h | 54 ++- drivers/iommu/iommufd/ioas.c | 8 +- drivers/iommu/iommufd/iommufd_private.h | 14 +- drivers/iommu/iommufd/iommufd_test.h | 10 + drivers/iommu/iommufd/main.c | 10 + drivers/iommu/iommufd/pages.c | 414 ++++++++++++++++-- drivers/iommu/iommufd/selftest.c | 143 ++++++ drivers/vfio/pci/vfio_pci_dmabuf.c | 34 ++ include/linux/vfio_pci_core.h | 4 + tools/testing/selftests/iommu/iommufd.c | 43 ++ tools/testing/selftests/iommu/iommufd_utils.h | 44 ++ 12 files changed, 786 insertions(+), 70 deletions(-) base-commit: f836737ed56db9e2d5b047c56a31e05af0f3f116 -- 2.43.0

12 hours, 1 minute

Re: [PATCH v3 19/28] drm/ttm: rework pipelined eviction fence handling

by Christian König

On 11/21/25 11:12, Pierre-Eric Pelloux-Prayer wrote: > Until now ttm stored a single pipelined eviction fence which means > drivers had to use a single entity for these evictions. > > To lift this requirement, this commit allows up to 8 entities to > be used. > > Ideally a dma_resv object would have been used as a container of > the eviction fences, but the locking rules makes it complex. > dma_resv all have the same ww_class, which means "Attempting to > lock more mutexes after ww_acquire_done." is an error. > > One alternative considered was to introduced a 2nd ww_class for > specific resv to hold a single "transient" lock (= the resv lock > would only be held for a short period, without taking any other > locks). > > The other option, is to statically reserve a fence array, and > extend the existing code to deal with N fences, instead of 1. > > The driver is still responsible to reserve the correct number > of fence slots. > > --- > v2: > - simplified code > - dropped n_fences > - name changes > v3: use ttm_resource_manager_cleanup > --- > > Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer(a)amd.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> Going to push separately to drm-misc-next on Monday. Regards, Christian. > --- > .../gpu/drm/ttm/tests/ttm_bo_validate_test.c | 11 +++-- > drivers/gpu/drm/ttm/tests/ttm_resource_test.c | 5 +- > drivers/gpu/drm/ttm/ttm_bo.c | 47 ++++++++++--------- > drivers/gpu/drm/ttm/ttm_bo_util.c | 38 ++++++++++++--- > drivers/gpu/drm/ttm/ttm_resource.c | 31 +++++++----- > include/drm/ttm/ttm_resource.h | 29 ++++++++---- > 6 files changed, 104 insertions(+), 57 deletions(-) > > diff --git a/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c b/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c > index 3148f5d3dbd6..8f71906c4238 100644 > --- a/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c > +++ b/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c > @@ -651,7 +651,7 @@ static void ttm_bo_validate_move_fence_signaled(struct kunit *test) > int err; > > man = ttm_manager_type(priv->ttm_dev, mem_type); > - man->move = dma_fence_get_stub(); > + man->eviction_fences[0] = dma_fence_get_stub(); > > bo = ttm_bo_kunit_init(test, test->priv, size, NULL); > bo->type = bo_type; > @@ -668,7 +668,7 @@ static void ttm_bo_validate_move_fence_signaled(struct kunit *test) > KUNIT_EXPECT_EQ(test, ctx.bytes_moved, size); > > ttm_bo_put(bo); > - dma_fence_put(man->move); > + dma_fence_put(man->eviction_fences[0]); > } > > static const struct ttm_bo_validate_test_case ttm_bo_validate_wait_cases[] = { > @@ -732,9 +732,9 @@ static void ttm_bo_validate_move_fence_not_signaled(struct kunit *test) > > spin_lock_init(&fence_lock); > man = ttm_manager_type(priv->ttm_dev, fst_mem); > - man->move = alloc_mock_fence(test); > + man->eviction_fences[0] = alloc_mock_fence(test); > > - task = kthread_create(threaded_fence_signal, man->move, "move-fence-signal"); > + task = kthread_create(threaded_fence_signal, man->eviction_fences[0], "move-fence-signal"); > if (IS_ERR(task)) > KUNIT_FAIL(test, "Couldn't create move fence signal task\n"); > > @@ -742,7 +742,8 @@ static void ttm_bo_validate_move_fence_not_signaled(struct kunit *test) > err = ttm_bo_validate(bo, placement_val, &ctx_val); > dma_resv_unlock(bo->base.resv); > > - dma_fence_wait_timeout(man->move, false, MAX_SCHEDULE_TIMEOUT); > + dma_fence_wait_timeout(man->eviction_fences[0], false, MAX_SCHEDULE_TIMEOUT); > + man->eviction_fences[0] = NULL; > > KUNIT_EXPECT_EQ(test, err, 0); > KUNIT_EXPECT_EQ(test, ctx_val.bytes_moved, size); > diff --git a/drivers/gpu/drm/ttm/tests/ttm_resource_test.c b/drivers/gpu/drm/ttm/tests/ttm_resource_test.c > index e6ea2bd01f07..c0e4e35e0442 100644 > --- a/drivers/gpu/drm/ttm/tests/ttm_resource_test.c > +++ b/drivers/gpu/drm/ttm/tests/ttm_resource_test.c > @@ -207,6 +207,7 @@ static void ttm_resource_manager_init_basic(struct kunit *test) > struct ttm_resource_test_priv *priv = test->priv; > struct ttm_resource_manager *man; > size_t size = SZ_16K; > + int i; > > man = kunit_kzalloc(test, sizeof(*man), GFP_KERNEL); > KUNIT_ASSERT_NOT_NULL(test, man); > @@ -216,8 +217,8 @@ static void ttm_resource_manager_init_basic(struct kunit *test) > KUNIT_ASSERT_PTR_EQ(test, man->bdev, priv->devs->ttm_dev); > KUNIT_ASSERT_EQ(test, man->size, size); > KUNIT_ASSERT_EQ(test, man->usage, 0); > - KUNIT_ASSERT_NULL(test, man->move); > - KUNIT_ASSERT_NOT_NULL(test, &man->move_lock); > + for (i = 0; i < TTM_NUM_MOVE_FENCES; i++) > + KUNIT_ASSERT_NULL(test, man->eviction_fences[i]); > > for (int i = 0; i < TTM_MAX_BO_PRIORITY; ++i) > KUNIT_ASSERT_TRUE(test, list_empty(&man->lru[i])); > diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c > index f4d9e68b21e7..0b3732ed6f6c 100644 > --- a/drivers/gpu/drm/ttm/ttm_bo.c > +++ b/drivers/gpu/drm/ttm/ttm_bo.c > @@ -658,34 +658,35 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo) > EXPORT_SYMBOL(ttm_bo_unpin); > > /* > - * Add the last move fence to the BO as kernel dependency and reserve a new > - * fence slot. > + * Add the pipelined eviction fencesto the BO as kernel dependency and reserve new > + * fence slots. > */ > -static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo, > - struct ttm_resource_manager *man, > - bool no_wait_gpu) > +static int ttm_bo_add_pipelined_eviction_fences(struct ttm_buffer_object *bo, > + struct ttm_resource_manager *man, > + bool no_wait_gpu) > { > struct dma_fence *fence; > - int ret; > + int i; > > - spin_lock(&man->move_lock); > - fence = dma_fence_get(man->move); > - spin_unlock(&man->move_lock); > + spin_lock(&man->eviction_lock); > + for (i = 0; i < TTM_NUM_MOVE_FENCES; i++) { > + fence = man->eviction_fences[i]; > + if (!fence) > + continue; > > - if (!fence) > - return 0; > - > - if (no_wait_gpu) { > - ret = dma_fence_is_signaled(fence) ? 0 : -EBUSY; > - dma_fence_put(fence); > - return ret; > + if (no_wait_gpu) { > + if (!dma_fence_is_signaled(fence)) { > + spin_unlock(&man->eviction_lock); > + return -EBUSY; > + } > + } else { > + dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_KERNEL); > + } > } > + spin_unlock(&man->eviction_lock); > > - dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_KERNEL); > - > - ret = dma_resv_reserve_fences(bo->base.resv, 1); > - dma_fence_put(fence); > - return ret; > + /* TODO: this call should be removed. */ > + return dma_resv_reserve_fences(bo->base.resv, 1); > } > > /** > @@ -718,7 +719,7 @@ static int ttm_bo_alloc_resource(struct ttm_buffer_object *bo, > int i, ret; > > ticket = dma_resv_locking_ctx(bo->base.resv); > - ret = dma_resv_reserve_fences(bo->base.resv, 1); > + ret = dma_resv_reserve_fences(bo->base.resv, TTM_NUM_MOVE_FENCES); > if (unlikely(ret)) > return ret; > > @@ -757,7 +758,7 @@ static int ttm_bo_alloc_resource(struct ttm_buffer_object *bo, > return ret; > } > > - ret = ttm_bo_add_move_fence(bo, man, ctx->no_wait_gpu); > + ret = ttm_bo_add_pipelined_eviction_fences(bo, man, ctx->no_wait_gpu); > if (unlikely(ret)) { > ttm_resource_free(bo, res); > if (ret == -EBUSY) > diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c > index acbbca9d5c92..2ff35d55e462 100644 > --- a/drivers/gpu/drm/ttm/ttm_bo_util.c > +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c > @@ -258,7 +258,7 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo, > ret = dma_resv_trylock(&fbo->base.base._resv); > WARN_ON(!ret); > > - ret = dma_resv_reserve_fences(&fbo->base.base._resv, 1); > + ret = dma_resv_reserve_fences(&fbo->base.base._resv, TTM_NUM_MOVE_FENCES); > if (ret) { > dma_resv_unlock(&fbo->base.base._resv); > kfree(fbo); > @@ -646,20 +646,44 @@ static void ttm_bo_move_pipeline_evict(struct ttm_buffer_object *bo, > { > struct ttm_device *bdev = bo->bdev; > struct ttm_resource_manager *from; > + struct dma_fence *tmp; > + int i; > > from = ttm_manager_type(bdev, bo->resource->mem_type); > > /** > * BO doesn't have a TTM we need to bind/unbind. Just remember > - * this eviction and free up the allocation > + * this eviction and free up the allocation. > + * The fence will be saved in the first free slot or in the slot > + * already used to store a fence from the same context. Since > + * drivers can't use more than TTM_NUM_MOVE_FENCES contexts for > + * evictions we should always find a slot to use. > */ > - spin_lock(&from->move_lock); > - if (!from->move || dma_fence_is_later(fence, from->move)) { > - dma_fence_put(from->move); > - from->move = dma_fence_get(fence); > + spin_lock(&from->eviction_lock); > + for (i = 0; i < TTM_NUM_MOVE_FENCES; i++) { > + tmp = from->eviction_fences[i]; > + if (!tmp) > + break; > + if (fence->context != tmp->context) > + continue; > + if (dma_fence_is_later(fence, tmp)) { > + dma_fence_put(tmp); > + break; > + } > + goto unlock; > + } > + if (i < TTM_NUM_MOVE_FENCES) { > + from->eviction_fences[i] = dma_fence_get(fence); > + } else { > + WARN(1, "not enough fence slots for all fence contexts"); > + spin_unlock(&from->eviction_lock); > + dma_fence_wait(fence, false); > + goto end; > } > - spin_unlock(&from->move_lock); > > +unlock: > + spin_unlock(&from->eviction_lock); > +end: > ttm_resource_free(bo, &bo->resource); > } > > diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c > index e2c82ad07eb4..62c34cafa387 100644 > --- a/drivers/gpu/drm/ttm/ttm_resource.c > +++ b/drivers/gpu/drm/ttm/ttm_resource.c > @@ -523,14 +523,15 @@ void ttm_resource_manager_init(struct ttm_resource_manager *man, > { > unsigned i; > > - spin_lock_init(&man->move_lock); > man->bdev = bdev; > man->size = size; > man->usage = 0; > > for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) > INIT_LIST_HEAD(&man->lru[i]); > - man->move = NULL; > + spin_lock_init(&man->eviction_lock); > + for (i = 0; i < TTM_NUM_MOVE_FENCES; i++) > + man->eviction_fences[i] = NULL; > } > EXPORT_SYMBOL(ttm_resource_manager_init); > > @@ -551,7 +552,7 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev, > .no_wait_gpu = false, > }; > struct dma_fence *fence; > - int ret; > + int ret, i; > > do { > ret = ttm_bo_evict_first(bdev, man, &ctx); > @@ -561,18 +562,24 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev, > if (ret && ret != -ENOENT) > return ret; > > - spin_lock(&man->move_lock); > - fence = dma_fence_get(man->move); > - spin_unlock(&man->move_lock); > + ret = 0; > > - if (fence) { > - ret = dma_fence_wait(fence, false); > - dma_fence_put(fence); > - if (ret) > - return ret; > + spin_lock(&man->eviction_lock); > + for (i = 0; i < TTM_NUM_MOVE_FENCES; i++) { > + fence = man->eviction_fences[i]; > + if (fence && !dma_fence_is_signaled(fence)) { > + dma_fence_get(fence); > + spin_unlock(&man->eviction_lock); > + ret = dma_fence_wait(fence, false); > + dma_fence_put(fence); > + if (ret) > + return ret; > + spin_lock(&man->eviction_lock); > + } > } > + spin_unlock(&man->eviction_lock); > > - return 0; > + return ret; > } > EXPORT_SYMBOL(ttm_resource_manager_evict_all); > > diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h > index f49daa504c36..50e6added509 100644 > --- a/include/drm/ttm/ttm_resource.h > +++ b/include/drm/ttm/ttm_resource.h > @@ -50,6 +50,15 @@ struct io_mapping; > struct sg_table; > struct scatterlist; > > +/** > + * define TTM_NUM_MOVE_FENCES - How many entities can be used for evictions > + * > + * Pipelined evictions can be spread on multiple entities. This > + * is the max number of entities that can be used by the driver > + * for that purpose. > + */ > +#define TTM_NUM_MOVE_FENCES 8 > + > /** > * enum ttm_lru_item_type - enumerate ttm_lru_item subclasses > */ > @@ -180,8 +189,8 @@ struct ttm_resource_manager_func { > * @size: Size of the managed region. > * @bdev: ttm device this manager belongs to > * @func: structure pointer implementing the range manager. See above > - * @move_lock: lock for move fence > - * @move: The fence of the last pipelined move operation. > + * @eviction_lock: lock for eviction fences > + * @eviction_fences: The fences of the last pipelined move operation. > * @lru: The lru list for this memory type. > * > * This structure is used to identify and manage memory types for a device. > @@ -195,12 +204,12 @@ struct ttm_resource_manager { > struct ttm_device *bdev; > uint64_t size; > const struct ttm_resource_manager_func *func; > - spinlock_t move_lock; > > - /* > - * Protected by @move_lock. > + /* This is very similar to a dma_resv object, but locking rules make > + * it difficult to use one in this context. > */ > - struct dma_fence *move; > + spinlock_t eviction_lock; > + struct dma_fence *eviction_fences[TTM_NUM_MOVE_FENCES]; > > /* > * Protected by the bdev->lru_lock. > @@ -421,8 +430,12 @@ static inline bool ttm_resource_manager_used(struct ttm_resource_manager *man) > static inline void > ttm_resource_manager_cleanup(struct ttm_resource_manager *man) > { > - dma_fence_put(man->move); > - man->move = NULL; > + int i; > + > + for (i = 0; i < TTM_NUM_MOVE_FENCES; i++) { > + dma_fence_put(man->eviction_fences[i]); > + man->eviction_fences[i] = NULL; > + } > } > > void ttm_lru_bulk_move_init(struct ttm_lru_bulk_move *bulk);

12 hours, 39 minutes

Re: [PATCH 6/9] iommufd: Have pfn_reader process DMABUF iopt_pages

by Jason Gunthorpe

On Thu, Nov 20, 2025 at 08:04:37AM +0000, Tian, Kevin wrote: > > From: Jason Gunthorpe <jgg(a)nvidia.com> > > Sent: Saturday, November 8, 2025 12:50 AM > > + > > +static int pfn_reader_fill_dmabuf(struct pfn_reader_dmabuf *dmabuf, > > + struct pfn_batch *batch, > > + unsigned long start_index, > > + unsigned long last_index) > > +{ > > + unsigned long start = dmabuf->start_offset + start_index * PAGE_SIZE; > > + > > + /* > > + * This works in PAGE_SIZE indexes, if the dmabuf is sliced and > > + * starts/ends at a sub page offset then the batch to domain code will > > + * adjust it. > > + */ > > dmabuf->start_offset comes from pages->dmabuf.start, which is initialized as: > > pages->dmabuf.start = start - start_byte; > > so it's always page-aligned. Where is the sub-page offset coming from? I need to go over this again to check it, this sub-page stuff is a bit convoluted. start_offset should include the sub page offset here.. > > @@ -1687,6 +1737,12 @@ static void __iopt_area_unfill_domain(struct > > iopt_area *area, > > > > lockdep_assert_held(&pages->mutex); > > > > + if (iopt_is_dmabuf(pages)) { > > + iopt_area_unmap_domain_range(area, domain, start_index, > > + last_index); > > + return; > > + } > > + > > this belongs to patch3? This is part of programming the domain with the dmabuf, the patch3 was about the revoke which is a slightly different topic though they are both similar. Thanks, Jason

13 hours, 19 minutes

Re: [PATCH 2/9] iommufd: Add DMABUF to iopt_pages

by Jason Gunthorpe

On Thu, Nov 20, 2025 at 07:55:04AM +0000, Tian, Kevin wrote: > > From: Jason Gunthorpe <jgg(a)nvidia.com> > > Sent: Saturday, November 8, 2025 12:50 AM > > > > > > @@ -2031,7 +2155,10 @@ int iopt_pages_rw_access(struct iopt_pages > > *pages, unsigned long start_byte, > > if ((flags & IOMMUFD_ACCESS_RW_WRITE) && !pages->writable) > > return -EPERM; > > > > - if (pages->type == IOPT_ADDRESS_FILE) > > + if (iopt_is_dmabuf(pages)) > > + return -EINVAL; > > + > > probably also add helpers for other types, e.g.: > > iopt_is_user() > iopt_is_memfd() The helper was to integrate the IS_ENABLED() check for DMABUF, there are not so many others uses, I think leave it to not bloat the patch. > > + if (pages->type != IOPT_ADDRESS_USER) > > return iopt_pages_rw_slow(pages, start_index, last_index, > > start_byte % PAGE_SIZE, data, > > length, > > flags); > > -- > > then the following WARN_ON() becomes useless: > > if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && > WARN_ON(pages->type != IOPT_ADDRESS_USER)) > return -EINVAL; Yep Thanks, Jason

13 hours, 25 minutes

Re: [PATCH v3 09/28] drm/amdgpu: pass the entity to use to ttm public functions

by Christian König

On 11/21/25 11:12, Pierre-Eric Pelloux-Prayer wrote: > This way the caller can select the one it wants to use. > > Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer(a)amd.com> I'm wondering if it wouldn't make sense to put a pointer to adev into each amdgpu_ttm_buffer_entity. But that is maybe something for another patch. For now: Reviewed-by: Christian König <christian.koenig(a)amd.com> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c | 3 +- > drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 4 +-- > drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 34 +++++++++---------- > drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 16 +++++---- > drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 3 +- > 5 files changed, 32 insertions(+), 28 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c > index 3636b757c974..a050167e76a4 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c > @@ -37,7 +37,8 @@ static int amdgpu_benchmark_do_move(struct amdgpu_device *adev, unsigned size, > > stime = ktime_get(); > for (i = 0; i < n; i++) { > - r = amdgpu_copy_buffer(adev, saddr, daddr, size, NULL, &fence, > + r = amdgpu_copy_buffer(adev, &adev->mman.default_entity, > + saddr, daddr, size, NULL, &fence, > false, 0); > if (r) > goto exit_do_move; > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c > index 926a3f09a776..858eb9fa061b 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c > @@ -1322,8 +1322,8 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo) > if (r) > goto out; > > - r = amdgpu_fill_buffer(abo, 0, &bo->base._resv, &fence, true, > - AMDGPU_KERNEL_JOB_ID_CLEAR_ON_RELEASE); > + r = amdgpu_fill_buffer(&adev->mman.clear_entity, abo, 0, &bo->base._resv, > + &fence, AMDGPU_KERNEL_JOB_ID_CLEAR_ON_RELEASE); > if (WARN_ON(r)) > goto out; > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > index 3d850893b97f..1d3afad885da 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > @@ -359,7 +359,7 @@ static int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev, > write_compress_disable)); > } > > - r = amdgpu_copy_buffer(adev, from, to, cur_size, resv, > + r = amdgpu_copy_buffer(adev, entity, from, to, cur_size, resv, > &next, true, copy_flags); > if (r) > goto error; > @@ -414,8 +414,9 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo, > (abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE)) { > struct dma_fence *wipe_fence = NULL; > > - r = amdgpu_fill_buffer(abo, 0, NULL, &wipe_fence, > - false, AMDGPU_KERNEL_JOB_ID_MOVE_BLIT); > + r = amdgpu_fill_buffer(&adev->mman.move_entity, > + abo, 0, NULL, &wipe_fence, > + AMDGPU_KERNEL_JOB_ID_MOVE_BLIT); > if (r) { > goto error; > } else if (wipe_fence) { > @@ -2258,7 +2259,9 @@ static int amdgpu_ttm_prepare_job(struct amdgpu_device *adev, > DMA_RESV_USAGE_BOOKKEEP); > } > > -int amdgpu_copy_buffer(struct amdgpu_device *adev, uint64_t src_offset, > +int amdgpu_copy_buffer(struct amdgpu_device *adev, > + struct amdgpu_ttm_buffer_entity *entity, > + uint64_t src_offset, > uint64_t dst_offset, uint32_t byte_count, > struct dma_resv *resv, > struct dma_fence **fence, > @@ -2282,7 +2285,7 @@ int amdgpu_copy_buffer(struct amdgpu_device *adev, uint64_t src_offset, > max_bytes = adev->mman.buffer_funcs->copy_max_bytes; > num_loops = DIV_ROUND_UP(byte_count, max_bytes); > num_dw = ALIGN(num_loops * adev->mman.buffer_funcs->copy_num_dw, 8); > - r = amdgpu_ttm_prepare_job(adev, &adev->mman.move_entity, num_dw, > + r = amdgpu_ttm_prepare_job(adev, entity, num_dw, > resv, vm_needs_flush, &job, > AMDGPU_KERNEL_JOB_ID_TTM_COPY_BUFFER); > if (r) > @@ -2411,22 +2414,18 @@ int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo, > return r; > } > > -int amdgpu_fill_buffer(struct amdgpu_bo *bo, > - uint32_t src_data, > - struct dma_resv *resv, > - struct dma_fence **f, > - bool delayed, > - u64 k_job_id) > +int amdgpu_fill_buffer(struct amdgpu_ttm_buffer_entity *entity, > + struct amdgpu_bo *bo, > + uint32_t src_data, > + struct dma_resv *resv, > + struct dma_fence **f, > + u64 k_job_id) > { > struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); > - struct amdgpu_ttm_buffer_entity *entity; > struct dma_fence *fence = NULL; > struct amdgpu_res_cursor dst; > int r; > > - entity = delayed ? &adev->mman.clear_entity : > - &adev->mman.move_entity; > - > if (!adev->mman.buffer_funcs_enabled) { > dev_err(adev->dev, > "Trying to clear memory with ring turned off.\n"); > @@ -2443,13 +2442,14 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo, > /* Never fill more than 256MiB at once to avoid timeouts */ > cur_size = min(dst.size, 256ULL << 20); > > - r = amdgpu_ttm_map_buffer(adev, &adev->mman.default_entity, > + r = amdgpu_ttm_map_buffer(adev, entity, > &bo->tbo, bo->tbo.resource, &dst, > 1, false, &cur_size, &to); > if (r) > goto error; > > - r = amdgpu_ttm_fill_mem(adev, entity, src_data, to, cur_size, resv, > + r = amdgpu_ttm_fill_mem(adev, entity, > + src_data, to, cur_size, resv, > &next, true, k_job_id); > if (r) > goto error; > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h > index 41bbc25680a2..9288599c9c46 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h > @@ -167,7 +167,9 @@ int amdgpu_ttm_init(struct amdgpu_device *adev); > void amdgpu_ttm_fini(struct amdgpu_device *adev); > void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, > bool enable); > -int amdgpu_copy_buffer(struct amdgpu_device *adev, uint64_t src_offset, > +int amdgpu_copy_buffer(struct amdgpu_device *adev, > + struct amdgpu_ttm_buffer_entity *entity, > + uint64_t src_offset, > uint64_t dst_offset, uint32_t byte_count, > struct dma_resv *resv, > struct dma_fence **fence, > @@ -175,12 +177,12 @@ int amdgpu_copy_buffer(struct amdgpu_device *adev, uint64_t src_offset, > int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo, > struct dma_resv *resv, > struct dma_fence **fence); > -int amdgpu_fill_buffer(struct amdgpu_bo *bo, > - uint32_t src_data, > - struct dma_resv *resv, > - struct dma_fence **fence, > - bool delayed, > - u64 k_job_id); > +int amdgpu_fill_buffer(struct amdgpu_ttm_buffer_entity *entity, > + struct amdgpu_bo *bo, > + uint32_t src_data, > + struct dma_resv *resv, > + struct dma_fence **f, > + u64 k_job_id); > > int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo); > void amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo); > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c > index ade1d4068d29..9c76f1ba0e55 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c > @@ -157,7 +157,8 @@ svm_migrate_copy_memory_gart(struct amdgpu_device *adev, dma_addr_t *sys, > goto out_unlock; > } > > - r = amdgpu_copy_buffer(adev, gart_s, gart_d, size * PAGE_SIZE, > + r = amdgpu_copy_buffer(adev, entity, > + gart_s, gart_d, size * PAGE_SIZE, > NULL, &next, true, 0); > if (r) { > dev_err(adev->dev, "fail %d to copy memory\n", r);

14 hours, 29 minutes

Re: [PATCH v3 06/28] drm/amdgpu: add amdgpu_ttm_job_submit helper

by Christian König

On 11/21/25 11:12, Pierre-Eric Pelloux-Prayer wrote: > Deduplicate the IB padding code and will also be used > later to check locking. > > Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer(a)amd.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 34 ++++++++++++------------- > 1 file changed, 16 insertions(+), 18 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > index 17e1892c44a2..be1232b2d55e 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > @@ -162,6 +162,18 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo, > *placement = abo->placement; > } > > +static struct dma_fence * > +amdgpu_ttm_job_submit(struct amdgpu_device *adev, struct amdgpu_job *job, u32 num_dw) > +{ > + struct amdgpu_ring *ring; > + > + ring = adev->mman.buffer_funcs_ring; > + amdgpu_ring_pad_ib(ring, &job->ibs[0]); > + WARN_ON(job->ibs[0].length_dw > num_dw); > + > + return amdgpu_job_submit(job); > +} > + > /** > * amdgpu_ttm_map_buffer - Map memory into the GART windows > * @adev: the device being used > @@ -185,7 +197,6 @@ static int amdgpu_ttm_map_buffer(struct amdgpu_device *adev, > { > unsigned int offset, num_pages, num_dw, num_bytes; > uint64_t src_addr, dst_addr; > - struct amdgpu_ring *ring; > struct amdgpu_job *job; > void *cpu_addr; > uint64_t flags; > @@ -240,10 +251,6 @@ static int amdgpu_ttm_map_buffer(struct amdgpu_device *adev, > amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_addr, > dst_addr, num_bytes, 0); > > - ring = adev->mman.buffer_funcs_ring; > - amdgpu_ring_pad_ib(ring, &job->ibs[0]); > - WARN_ON(job->ibs[0].length_dw > num_dw); > - > flags = amdgpu_ttm_tt_pte_flags(adev, bo->ttm, mem); > if (tmz) > flags |= AMDGPU_PTE_TMZ; > @@ -261,7 +268,7 @@ static int amdgpu_ttm_map_buffer(struct amdgpu_device *adev, > amdgpu_gart_map_vram_range(adev, pa, 0, num_pages, flags, cpu_addr); > } > > - dma_fence_put(amdgpu_job_submit(job)); > + dma_fence_put(amdgpu_ttm_job_submit(adev, job, num_dw)); > return 0; > } > > @@ -1497,10 +1504,7 @@ static int amdgpu_ttm_access_memory_sdma(struct ttm_buffer_object *bo, > amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_addr, dst_addr, > PAGE_SIZE, 0); > > - amdgpu_ring_pad_ib(adev->mman.buffer_funcs_ring, &job->ibs[0]); > - WARN_ON(job->ibs[0].length_dw > num_dw); > - > - fence = amdgpu_job_submit(job); > + fence = amdgpu_ttm_job_submit(adev, job, num_dw); > > if (!dma_fence_wait_timeout(fence, false, adev->sdma_timeout)) > r = -ETIMEDOUT; > @@ -2285,11 +2289,9 @@ int amdgpu_copy_buffer(struct amdgpu_device *adev, uint64_t src_offset, > byte_count -= cur_size_in_bytes; > } > > - amdgpu_ring_pad_ib(ring, &job->ibs[0]); > - WARN_ON(job->ibs[0].length_dw > num_dw); > - *fence = amdgpu_job_submit(job); > if (r) > goto error_free; > + *fence = amdgpu_ttm_job_submit(adev, job, num_dw); > > return r; > > @@ -2307,7 +2309,6 @@ static int amdgpu_ttm_fill_mem(struct amdgpu_device *adev, uint32_t src_data, > u64 k_job_id) > { > unsigned int num_loops, num_dw; > - struct amdgpu_ring *ring; > struct amdgpu_job *job; > uint32_t max_bytes; > unsigned int i; > @@ -2331,10 +2332,7 @@ static int amdgpu_ttm_fill_mem(struct amdgpu_device *adev, uint32_t src_data, > byte_count -= cur_size; > } > > - ring = adev->mman.buffer_funcs_ring; > - amdgpu_ring_pad_ib(ring, &job->ibs[0]); > - WARN_ON(job->ibs[0].length_dw > num_dw); > - *fence = amdgpu_job_submit(job); > + *fence = amdgpu_ttm_job_submit(adev, job, num_dw); > return 0; > } >

14 hours, 51 minutes

Re: [PATCH v9 10/11] vfio/pci: Add dma-buf export support for MMIO regions

by Leon Romanovsky

On Thu, Nov 20, 2025 at 05:04:13PM -0700, Alex Williamson wrote: > On Thu, 20 Nov 2025 11:28:29 +0200 > Leon Romanovsky <leon(a)kernel.org> wrote: > > diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c > > index 142b84b3f225..51a3bcc26f8b 100644 > > --- a/drivers/vfio/pci/vfio_pci_core.c > > +++ b/drivers/vfio/pci/vfio_pci_core.c > ... > > @@ -2487,8 +2500,11 @@ static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set, > > > > err_undo: > > list_for_each_entry_from_reverse(vdev, &dev_set->device_list, > > - vdev.dev_set_list) > > + vdev.dev_set_list) { > > + if (__vfio_pci_memory_enabled(vdev)) > > + vfio_pci_dma_buf_move(vdev, false); > > up_write(&vdev->memory_lock); > > + } > > I ran into a bug here. In the hot reset path we can have dev_sets > where one or more devices are not opened by the user. The vconfig > buffer for the device is established on open. However: > > bool __vfio_pci_memory_enabled(struct vfio_pci_core_device *vdev) > { > struct pci_dev *pdev = vdev->pdev; > u16 cmd = le16_to_cpu(*(__le16 *)&vdev->vconfig[PCI_COMMAND]); > ... > > Leads to a NULL pointer dereference. > > I think the most straightforward fix is simply to test the open_count > on the vfio_device, which is also protected by the dev_set->lock that > we already hold here: > > --- a/drivers/vfio/pci/vfio_pci_core.c > +++ b/drivers/vfio/pci/vfio_pci_core.c > @@ -2501,7 +2501,7 @@ static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set, > err_undo: > list_for_each_entry_from_reverse(vdev, &dev_set->device_list, > vdev.dev_set_list) { > - if (__vfio_pci_memory_enabled(vdev)) > + if (vdev->vdev.open_count && __vfio_pci_memory_enabled(vdev)) > vfio_pci_dma_buf_move(vdev, false); > up_write(&vdev->memory_lock); > } > > Any other suggestions? This should be the only reset path with this > nuance of affecting non-opened devices. Thanks, It seems right to me. Thanks > > Alex

20 hours, 10 minutes

Re: [PATCH v2] dma-buf: system_heap: use larger contiguous mappings instead of per-page mmap

by Sumit Semwal

Hi Barry, On Fri, 21 Nov 2025 at 06:54, Barry Song <21cnbao(a)gmail.com> wrote: > > Hi Sumit, > > > > > Using the micro-benchmark below, we see that mmap becomes > > 3.5X faster: > > > Marcin pointed out to me off-tree that it is actually 35x faster, > not 3.5x faster. Sorry for my poor math. I assume you can fix this > when merging it? Sure, I corrected this, and is merged to drm-misc-next Thanks, Sumit. > > > > > W/ patch: > > > > ~ # ./a.out > > mmap 512MB took 200266.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 198151.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 197069.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 196781.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 198102.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 195552.000 us, verify OK > > > > W/o patch: > > > > ~ # ./a.out > > mmap 512MB took 6987470.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 6970739.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 6984383.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 6971311.000 us, verify OK > > ~ # ./a.out > > mmap 512MB took 6991680.000 us, verify OK > > > Thanks > Barry

22 hours

Re: [PATCH v9 10/11] vfio/pci: Add dma-buf export support for MMIO regions

by Jason Gunthorpe

On Thu, Nov 20, 2025 at 05:04:13PM -0700, Alex Williamson wrote: > @@ -2501,7 +2501,7 @@ static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set, > err_undo: > list_for_each_entry_from_reverse(vdev, &dev_set->device_list, > vdev.dev_set_list) { > - if (__vfio_pci_memory_enabled(vdev)) > + if (vdev->vdev.open_count && __vfio_pci_memory_enabled(vdev)) > vfio_pci_dma_buf_move(vdev, false); > up_write(&vdev->memory_lock); > } > > Any other suggestions? This should be the only reset path with this > nuance of affecting non-opened devices. Thanks, Seems reasonable, but should it be in __vfio_pci_memory_enabled() just to be robust? Jason

1 day, 3 hours

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