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[PATCH v1 00/20] drm/amdgpu: use all SDMA instances for TTM clears and moves

by Pierre-Eric Pelloux-Prayer

The drm/ttm patch modifies TTM to support multiple contexts for the pipelined moves. Then amdgpu/ttm is updated to express dependencies between jobs explicitely, instead of relying on the ordering of execution guaranteed by the use of a single instance. With all of this in place, we can use multiple entities, with each having access to the available SDMA instances. This rework also gives the opportunity to merge the clear functions into a single one and to optimize a bit GART usage. (The first patch of the series has already been merged through drm-misc but I'm including it here to reduce conflicts) Pierre-Eric Pelloux-Prayer (20): drm/amdgpu: give each kernel job a unique id drm/ttm: rework pipelined eviction fence handling drm/amdgpu: remove direct_submit arg from amdgpu_copy_buffer drm/amdgpu: introduce amdgpu_ttm_entity drm/amdgpu: pass the entity to use to ttm functions drm/amdgpu: statically assign gart windows to ttm entities drm/amdgpu: allocate multiple clear entities drm/amdgpu: allocate multiple move entities drm/amdgpu: pass optional dependency to amdgpu_fill_buffer drm/amdgpu: prepare amdgpu_fill_buffer to use N entities drm/amdgpu: use multiple entities in amdgpu_fill_buffer drm/amdgpu: use TTM_FENCES_MAX_SLOT_COUNT drm/amdgpu: use multiple entities in amdgpu_move_blit drm/amdgpu: pass all the sdma rings to amdgpu_mman drm/amdgpu: introduce amdgpu_sdma_set_vm_pte_scheds drm/amdgpu: give ttm entities access to all the sdma scheds drm/amdgpu: get rid of amdgpu_ttm_clear_buffer drm/amdgpu: rename amdgpu_fill_buffer as amdgpu_clear_buffer drm/amdgpu: use larger gart window when possible drm/amdgpu: double AMDGPU_GTT_MAX_TRANSFER_SIZE drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 + drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c | 7 +- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 5 +- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 8 +- drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 3 +- drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 23 +- drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 6 +- drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 5 +- drivers/gpu/drm/amd/amdgpu/amdgpu_job.h | 19 +- drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c | 3 +- drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 19 +- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 496 ++++++++++++------ drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 51 +- drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c | 3 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c | 5 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c | 8 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 24 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vm_cpu.c | 4 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c | 4 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 12 +- drivers/gpu/drm/amd/amdgpu/cik_sdma.c | 10 +- drivers/gpu/drm/amd/amdgpu/sdma_v2_4.c | 10 +- drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c | 10 +- drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 17 +- drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c | 17 +- drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c | 10 +- drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c | 10 +- drivers/gpu/drm/amd/amdgpu/sdma_v6_0.c | 10 +- drivers/gpu/drm/amd/amdgpu/sdma_v7_0.c | 10 +- drivers/gpu/drm/amd/amdgpu/si_dma.c | 10 +- drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c | 6 +- drivers/gpu/drm/amd/amdgpu/uvd_v7_0.c | 6 +- drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 31 +- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 2 +- .../amd/display/amdgpu_dm/amdgpu_dm_plane.c | 2 +- .../drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c | 2 +- .../gpu/drm/ttm/tests/ttm_bo_validate_test.c | 13 +- drivers/gpu/drm/ttm/tests/ttm_resource_test.c | 5 +- drivers/gpu/drm/ttm/ttm_bo.c | 56 +- drivers/gpu/drm/ttm/ttm_bo_util.c | 36 +- drivers/gpu/drm/ttm/ttm_resource.c | 45 +- include/drm/ttm/ttm_resource.h | 34 +- 45 files changed, 651 insertions(+), 414 deletions(-) -- 2.43.0

6 months

[PATCH v1 00/23] treewide: Introduce %ptS for struct timespec64 and convert users

by Andy Shevchenko

Here is the third part of unification time printing in the kernel. This time for struct timespec64. The first patch brings support into printf() implementation (test cases and documentation update included) followed by the treewide conversion of the current users. The idea is to have one or a few biggest users included, the rest can be taken next release cycle on the subsystem basis, but I won't object if the respective maintainers already give their tags. Depending on the tags received it may go via dedicated subsystem or via PRINTK tree. Note, not everything was compile-tested. Kunit test has been passed, though. Andy Shevchenko (23): lib/vsprintf: Add specifier for printing struct timespec64 ALSA: seq: Switch to use %ptSp ceph: Switch to use %ptSp libceph: Switch to use %ptSp dma-buf: Switch to use %ptSp drm/amdgpu: Switch to use %ptSp drm/msm: Switch to use %ptSp drm/vblank: Switch to use %ptSp drm/xe: Switch to use %ptSp e1000e: Switch to use %ptSp igb: Switch to use %ptSp ipmi: Switch to use %ptSp media: av7110: Switch to use %ptSp media: v4l2-ioctl: Switch to use %ptSp mmc: mmc_test: Switch to use %ptSp net: dsa: sja1105: Switch to use %ptSp PCI: epf-test: Switch to use %ptSp pps: Switch to use %ptSp ptp: ocp: Switch to use %ptSp s390/dasd: Switch to use %ptSp scsi: fnic: Switch to use %ptS scsi: snic: Switch to use %ptSp tracing: Switch to use %ptSp Documentation/core-api/printk-formats.rst | 11 ++++- drivers/char/ipmi/ipmi_si_intf.c | 3 +- drivers/char/ipmi/ipmi_ssif.c | 6 +-- drivers/dma-buf/sync_debug.c | 2 +- .../gpu/drm/amd/amdgpu/amdgpu_dev_coredump.c | 3 +- drivers/gpu/drm/drm_vblank.c | 6 +-- .../gpu/drm/msm/disp/msm_disp_snapshot_util.c | 3 +- drivers/gpu/drm/msm/msm_gpu.c | 3 +- drivers/gpu/drm/xe/xe_devcoredump.c | 4 +- drivers/media/v4l2-core/v4l2-ioctl.c | 5 +- drivers/mmc/core/mmc_test.c | 18 +++---- drivers/net/dsa/sja1105/sja1105_tas.c | 8 ++-- drivers/net/ethernet/intel/e1000e/ptp.c | 7 +-- drivers/net/ethernet/intel/igb/igb_ptp.c | 7 +-- drivers/pci/endpoint/functions/pci-epf-test.c | 5 +- drivers/pps/generators/pps_gen_parport.c | 3 +- drivers/pps/kapi.c | 3 +- drivers/ptp/ptp_ocp.c | 15 +++--- drivers/s390/block/dasd.c | 3 +- drivers/scsi/fnic/fnic_trace.c | 46 ++++++++---------- drivers/scsi/snic/snic_debugfs.c | 10 ++-- drivers/scsi/snic/snic_trc.c | 5 +- drivers/staging/media/av7110/av7110.c | 2 +- fs/ceph/dir.c | 5 +- fs/ceph/inode.c | 47 ++++++------------- fs/ceph/xattr.c | 6 +-- kernel/trace/trace_output.c | 6 +-- lib/tests/printf_kunit.c | 4 ++ lib/vsprintf.c | 25 ++++++++++ net/ceph/messenger_v2.c | 6 +-- sound/core/seq/seq_queue.c | 2 +- sound/core/seq/seq_timer.c | 6 +-- 32 files changed, 131 insertions(+), 154 deletions(-) -- 2.50.1

6 months

[PATCH 0/8] 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/cover.1760368250.git.leon@kernel.org/ 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 The branch has various modifications to Leon's series I've suggested. Jason Gunthorpe (8): 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 | 74 +++- drivers/iommu/iommufd/io_pagetable.h | 53 ++- drivers/iommu/iommufd/ioas.c | 8 +- drivers/iommu/iommufd/iommufd_private.h | 13 +- drivers/iommu/iommufd/iommufd_test.h | 10 + drivers/iommu/iommufd/main.c | 10 + drivers/iommu/iommufd/pages.c | 407 ++++++++++++++++-- drivers/iommu/iommufd/selftest.c | 142 ++++++ tools/testing/selftests/iommu/iommufd.c | 43 ++ tools/testing/selftests/iommu/iommufd_utils.h | 44 ++ 10 files changed, 741 insertions(+), 63 deletions(-) base-commit: fc882154e421f82677925d33577226e776bb07a4 -- 2.43.0

6 months, 1 week

[PATCH v3] drm/sched: Fix deadlock in drm_sched_entity_kill_jobs_cb

by Pierre-Eric Pelloux-Prayer

The Mesa issue referenced below pointed out a possible deadlock: [ 1231.611031] Possible interrupt unsafe locking scenario: [ 1231.611033] CPU0 CPU1 [ 1231.611034] ---- ---- [ 1231.611035] lock(&xa->xa_lock#17); [ 1231.611038] local_irq_disable(); [ 1231.611039] lock(&fence->lock); [ 1231.611041] lock(&xa->xa_lock#17); [ 1231.611044] <Interrupt> [ 1231.611045] lock(&fence->lock); [ 1231.611047] *** DEADLOCK *** In this example, CPU0 would be any function accessing job->dependencies through the xa_* functions that doesn't disable interrupts (eg: drm_sched_job_add_dependency, drm_sched_entity_kill_jobs_cb). CPU1 is executing drm_sched_entity_kill_jobs_cb as a fence signalling callback so in an interrupt context. It will deadlock when trying to grab the xa_lock which is already held by CPU0. Replacing all xa_* usage by their xa_*_irq counterparts would fix this issue, but Christian pointed out another issue: dma_fence_signal takes fence.lock and so does dma_fence_add_callback. dma_fence_signal() // locks f1.lock -> drm_sched_entity_kill_jobs_cb() -> foreach dependencies -> dma_fence_add_callback() // locks f2.lock This will deadlock if f1 and f2 share the same spinlock. To fix both issues, the code iterating on dependencies and re-arming them is moved out to drm_sched_entity_kill_jobs_work. v2: reworded commit message (Philipp) v3: added Fixes tag (Philipp) Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini") Link: https://gitlab.freedesktop.org/mesa/mesa/-/issues/13908 Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov(a)gmail.com> Suggested-by: Christian König <christian.koenig(a)amd.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer(a)amd.com> --- drivers/gpu/drm/scheduler/sched_entity.c | 34 +++++++++++++----------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index c8e949f4a568..fe174a4857be 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -173,26 +173,15 @@ int drm_sched_entity_error(struct drm_sched_entity *entity) } EXPORT_SYMBOL(drm_sched_entity_error); +static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, + struct dma_fence_cb *cb); + static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk) { struct drm_sched_job *job = container_of(wrk, typeof(*job), work); - - drm_sched_fence_scheduled(job->s_fence, NULL); - drm_sched_fence_finished(job->s_fence, -ESRCH); - WARN_ON(job->s_fence->parent); - job->sched->ops->free_job(job); -} - -/* Signal the scheduler finished fence when the entity in question is killed. */ -static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, - struct dma_fence_cb *cb) -{ - struct drm_sched_job *job = container_of(cb, struct drm_sched_job, - finish_cb); + struct dma_fence *f; unsigned long index; - dma_fence_put(f); - /* Wait for all dependencies to avoid data corruptions */ xa_for_each(&job->dependencies, index, f) { struct drm_sched_fence *s_fence = to_drm_sched_fence(f); @@ -220,6 +209,21 @@ static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, dma_fence_put(f); } + drm_sched_fence_scheduled(job->s_fence, NULL); + drm_sched_fence_finished(job->s_fence, -ESRCH); + WARN_ON(job->s_fence->parent); + job->sched->ops->free_job(job); +} + +/* Signal the scheduler finished fence when the entity in question is killed. */ +static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, + struct dma_fence_cb *cb) +{ + struct drm_sched_job *job = container_of(cb, struct drm_sched_job, + finish_cb); + + dma_fence_put(f); + INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work); schedule_work(&job->work); } -- 2.43.0

6 months, 1 week

[PATCH] i2c: qcom-geni: make sure I2C hub controllers can't use SE DMA

by Neil Armstrong

The I2C Hub controller is a simpler GENI I2C variant that doesn't support DMA at all, add a no_dma flag to make sure it nevers selects the SE DMA mode with mappable 32bytes long transfers. Fixes: cacd9643eca7 ("i2c: qcom-geni: add support for I2C Master Hub variant") Signed-off-by: Neil Armstrong <neil.armstrong(a)linaro.org> --- drivers/i2c/busses/i2c-qcom-geni.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index 43fdd89b8beb..bfb352b04902 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -97,6 +97,7 @@ struct geni_i2c_dev { dma_addr_t dma_addr; struct dma_chan *tx_c; struct dma_chan *rx_c; + bool no_dma; bool gpi_mode; bool abort_done; }; @@ -425,7 +426,7 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, size_t len = msg->len; struct i2c_msg *cur; - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + dma_buf = gi2c->no_dma ? NULL : i2c_get_dma_safe_msg_buf(msg, 32); if (dma_buf) geni_se_select_mode(se, GENI_SE_DMA); else @@ -464,7 +465,7 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, size_t len = msg->len; struct i2c_msg *cur; - dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); + dma_buf = gi2c->no_dma ? NULL : i2c_get_dma_safe_msg_buf(msg, 32); if (dma_buf) geni_se_select_mode(se, GENI_SE_DMA); else @@ -880,10 +881,12 @@ static int geni_i2c_probe(struct platform_device *pdev) goto err_resources; } - if (desc && desc->no_dma_support) + if (desc && desc->no_dma_support) { fifo_disable = false; - else + gi2c->no_dma = true; + } else { fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE; + } if (fifo_disable) { /* FIFO is disabled, so we can only use GPI DMA */ --- base-commit: dcb6fa37fd7bc9c3d2b066329b0d27dedf8becaa change-id: 20251029-topic-sm8x50-geni-i2c-hub-no-dma-8812576a65cb Best regards, -- Neil Armstrong <neil.armstrong(a)linaro.org>

6 months, 1 week

[PATCH net-next v4 0/6] Add AF_XDP zero copy support

by Meghana Malladi

This series adds AF_XDP zero coppy support to icssg driver. Tests were performed on AM64x-EVM with xdpsock application [1]. A clear improvement is seen Transmit (txonly) and receive (rxdrop) for 64 byte packets. 1500 byte test seems to be limited by line rate (1G link) so no improvement seen there in packet rate Having some issue with l2fwd as the benchmarking numbers show 0 for 64 byte packets after forwading first batch packets and I am currently looking into it. AF_XDP performance using 64 byte packets in Kpps. Benchmark: XDP-SKB XDP-Native XDP-Native(ZeroCopy) rxdrop 259 462 645 txonly 350 354 760 l2fwd 178 240 0 AF_XDP performance using 1500 byte packets in Kpps. Benchmark: XDP-SKB XDP-Native XDP-Native(ZeroCopy) rxdrop 82 82 82 txonly 81 82 82 l2fwd 81 82 82 [1]: https://github.com/xdp-project/bpf-examples/tree/master/AF_XDP-example v3: https://lore.kernel.org/all/20251014105613.2808674-1-m-malladi@ti.com/ v4-v3: - Rebased to the latest tip Meghana Malladi (6): net: ti: icssg-prueth: Add functions to create and destroy Rx/Tx queues net: ti: icssg-prueth: Add XSK pool helpers net: ti: icssg-prueth: Add AF_XDP zero copy for TX net: ti: icssg-prueth: Make emac_run_xdp function independent of page net: ti: icssg-prueth: Add AF_XDP zero copy for RX net: ti: icssg-prueth: Enable zero copy in XDP features drivers/net/ethernet/ti/icssg/icssg_common.c | 471 ++++++++++++++++--- drivers/net/ethernet/ti/icssg/icssg_prueth.c | 394 +++++++++++++--- drivers/net/ethernet/ti/icssg/icssg_prueth.h | 25 +- 3 files changed, 741 insertions(+), 149 deletions(-) base-commit: d550d63d0082268a31e93a10c64cbc2476b98b24 -- 2.43.0

6 months, 1 week

[PATCH v2] drm/sched: Fix deadlock in drm_sched_entity_kill_jobs_cb

by Pierre-Eric Pelloux-Prayer

The Mesa issue referenced below pointed out a possible deadlock: [ 1231.611031] Possible interrupt unsafe locking scenario: [ 1231.611033] CPU0 CPU1 [ 1231.611034] ---- ---- [ 1231.611035] lock(&xa->xa_lock#17); [ 1231.611038] local_irq_disable(); [ 1231.611039] lock(&fence->lock); [ 1231.611041] lock(&xa->xa_lock#17); [ 1231.611044] <Interrupt> [ 1231.611045] lock(&fence->lock); [ 1231.611047] *** DEADLOCK *** In this example, CPU0 would be any function accessing job->dependencies through the xa_* functions that doesn't disable interrupts (eg: drm_sched_job_add_dependency, drm_sched_entity_kill_jobs_cb). CPU1 is executing drm_sched_entity_kill_jobs_cb as a fence signalling callback so in an interrupt context. It will deadlock when trying to grab the xa_lock which is already held by CPU0. Replacing all xa_* usage by their xa_*_irq counterparts would fix this issue, but Christian pointed out another issue: dma_fence_signal takes fence.lock and so does dma_fence_add_callback. dma_fence_signal() // locks f1.lock -> drm_sched_entity_kill_jobs_cb() -> foreach dependencies -> dma_fence_add_callback() // locks f2.lock This will deadlock if f1 and f2 share the same spinlock. To fix both issues, the code iterating on dependencies and re-arming them is moved out to drm_sched_entity_kill_jobs_work. Link: https://gitlab.freedesktop.org/mesa/mesa/-/issues/13908 Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov(a)gmail.com> Suggested-by: Christian König <christian.koenig(a)amd.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer(a)amd.com> --- drivers/gpu/drm/scheduler/sched_entity.c | 34 +++++++++++++----------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index c8e949f4a568..fe174a4857be 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -173,26 +173,15 @@ int drm_sched_entity_error(struct drm_sched_entity *entity) } EXPORT_SYMBOL(drm_sched_entity_error); +static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, + struct dma_fence_cb *cb); + static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk) { struct drm_sched_job *job = container_of(wrk, typeof(*job), work); - - drm_sched_fence_scheduled(job->s_fence, NULL); - drm_sched_fence_finished(job->s_fence, -ESRCH); - WARN_ON(job->s_fence->parent); - job->sched->ops->free_job(job); -} - -/* Signal the scheduler finished fence when the entity in question is killed. */ -static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, - struct dma_fence_cb *cb) -{ - struct drm_sched_job *job = container_of(cb, struct drm_sched_job, - finish_cb); + struct dma_fence *f; unsigned long index; - dma_fence_put(f); - /* Wait for all dependencies to avoid data corruptions */ xa_for_each(&job->dependencies, index, f) { struct drm_sched_fence *s_fence = to_drm_sched_fence(f); @@ -220,6 +209,21 @@ static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, dma_fence_put(f); } + drm_sched_fence_scheduled(job->s_fence, NULL); + drm_sched_fence_finished(job->s_fence, -ESRCH); + WARN_ON(job->s_fence->parent); + job->sched->ops->free_job(job); +} + +/* Signal the scheduler finished fence when the entity in question is killed. */ +static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, + struct dma_fence_cb *cb) +{ + struct drm_sched_job *job = container_of(cb, struct drm_sched_job, + finish_cb); + + dma_fence_put(f); + INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work); schedule_work(&job->work); } -- 2.43.0

6 months, 2 weeks

[PATCH v5 0/9] vfio/pci: Allow MMIO regions to be exported through dma-buf

by Leon Romanovsky

Changelog: v5: * Rebased on top of v6.18-rc1. * Added more validation logic to make sure that DMA-BUF length doesn't overflow in various scenarios. * Hide kernel config from the users. * Fixed type conversion issue. DMA ranges are exposed with u64 length, but DMA-BUF uses "unsigned int" as a length for SG entries. * Added check to prevent from VFIO drivers which reports BAR size different from PCI, do not use DMA-BUF functionality. v4: https://lore.kernel.org/all/cover.1759070796.git.leon@kernel.org * Split pcim_p2pdma_provider() to two functions, one that initializes array of providers and another to return right provider pointer. v3: https://lore.kernel.org/all/cover.1758804980.git.leon@kernel.org * Changed pcim_p2pdma_enable() to be pcim_p2pdma_provider(). * Cache provider in vfio_pci_dma_buf struct instead of BAR index. * Removed misleading comment from pcim_p2pdma_provider(). * Moved MMIO check to be in pcim_p2pdma_provider(). v2: https://lore.kernel.org/all/cover.1757589589.git.leon@kernel.org/ * Added extra patch which adds new CONFIG, so next patches can reuse * it. * Squashed "PCI/P2PDMA: Remove redundant bus_offset from map state" into the other patch. * Fixed revoke calls to be aligned with true->false semantics. * Extended p2pdma_providers to be per-BAR and not global to whole * device. * Fixed possible race between dmabuf states and revoke. * Moved revoke to PCI BAR zap block. v1: https://lore.kernel.org/all/cover.1754311439.git.leon@kernel.org * Changed commit messages. * Reused DMA_ATTR_MMIO attribute. * Returned support for multiple DMA ranges per-dMABUF. v0: https://lore.kernel.org/all/cover.1753274085.git.leonro@nvidia.com --------------------------------------------------------------------------- Based on "[PATCH v6 00/16] dma-mapping: migrate to physical address-based API" https://lore.kernel.org/all/cover.1757423202.git.leonro@nvidia.com/ series. --------------------------------------------------------------------------- This series extends the VFIO PCI subsystem to support exporting MMIO regions from PCI device BARs as dma-buf objects, enabling safe sharing of non-struct page memory with controlled lifetime management. This allows RDMA and other subsystems to import dma-buf FDs and build them into memory regions for PCI P2P operations. The series supports a use case for SPDK where a NVMe device will be owned by SPDK through VFIO but interacting with a RDMA device. The RDMA device may directly access the NVMe CMB or directly manipulate the NVMe device's doorbell using PCI P2P. However, as a general mechanism, it can support many other scenarios with VFIO. This dmabuf approach can be usable by iommufd as well for generic and safe P2P mappings. In addition to the SPDK use-case mentioned above, the capability added in this patch series can also be useful when a buffer (located in device memory such as VRAM) needs to be shared between any two dGPU devices or instances (assuming one of them is bound to VFIO PCI) as long as they are P2P DMA compatible. The implementation provides a revocable attachment mechanism using dma-buf move operations. MMIO regions are normally pinned as BARs don't change physical addresses, but access is revoked when the VFIO device is closed or a PCI reset is issued. This ensures kernel self-defense against potentially hostile userspace. The series includes significant refactoring of the PCI P2PDMA subsystem to separate core P2P functionality from memory allocation features, making it more modular and suitable for VFIO use cases that don't need struct page support. ----------------------------------------------------------------------- The series is based originally on https://lore.kernel.org/all/20250307052248.405803-1-vivek.kasireddy@intel.c… but heavily rewritten to be based on DMA physical API. ----------------------------------------------------------------------- The WIP branch can be found here: https://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma.git/log/?h=… Thanks Leon Romanovsky (7): PCI/P2PDMA: Separate the mmap() support from the core logic PCI/P2PDMA: Simplify bus address mapping API PCI/P2PDMA: Refactor to separate core P2P functionality from memory allocation PCI/P2PDMA: Export pci_p2pdma_map_type() function types: move phys_vec definition to common header vfio/pci: Enable peer-to-peer DMA transactions by default vfio/pci: Add dma-buf export support for MMIO regions Vivek Kasireddy (2): vfio: Export vfio device get and put registration helpers vfio/pci: Share the core device pointer while invoking feature functions block/blk-mq-dma.c | 7 +- drivers/iommu/dma-iommu.c | 4 +- drivers/pci/p2pdma.c | 175 ++++++++--- drivers/vfio/pci/Kconfig | 3 + drivers/vfio/pci/Makefile | 2 + drivers/vfio/pci/vfio_pci_config.c | 22 +- drivers/vfio/pci/vfio_pci_core.c | 63 ++-- drivers/vfio/pci/vfio_pci_dmabuf.c | 446 +++++++++++++++++++++++++++++ drivers/vfio/pci/vfio_pci_priv.h | 23 ++ drivers/vfio/vfio_main.c | 2 + include/linux/pci-p2pdma.h | 120 +++++--- include/linux/types.h | 5 + include/linux/vfio.h | 2 + include/linux/vfio_pci_core.h | 1 + include/uapi/linux/vfio.h | 25 ++ kernel/dma/direct.c | 4 +- mm/hmm.c | 2 +- 17 files changed, 785 insertions(+), 121 deletions(-) create mode 100644 drivers/vfio/pci/vfio_pci_dmabuf.c -- 2.51.0

6 months, 2 weeks

[PATCH v1] drm/sched: fix deadlock in drm_sched_entity_kill_jobs_cb

by Pierre-Eric Pelloux-Prayer

https://gitlab.freedesktop.org/mesa/mesa/-/issues/13908 pointed out a possible deadlock: [ 1231.611031] Possible interrupt unsafe locking scenario: [ 1231.611033] CPU0 CPU1 [ 1231.611034] ---- ---- [ 1231.611035] lock(&xa->xa_lock#17); [ 1231.611038] local_irq_disable(); [ 1231.611039] lock(&fence->lock); [ 1231.611041] lock(&xa->xa_lock#17); [ 1231.611044] <Interrupt> [ 1231.611045] lock(&fence->lock); [ 1231.611047] *** DEADLOCK *** My initial fix was to replace xa_erase by xa_erase_irq, but Christian pointed out that calling dma_fence_add_callback from a callback can also deadlock if the signalling fence and the one passed to dma_fence_add_callback share the same lock. To fix both issues, the code iterating on dependencies and re-arming them is moved out to drm_sched_entity_kill_jobs_work. Suggested-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer(a)amd.com> --- drivers/gpu/drm/scheduler/sched_entity.c | 34 +++++++++++++----------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index c8e949f4a568..fe174a4857be 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -173,26 +173,15 @@ int drm_sched_entity_error(struct drm_sched_entity *entity) } EXPORT_SYMBOL(drm_sched_entity_error); +static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, + struct dma_fence_cb *cb); + static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk) { struct drm_sched_job *job = container_of(wrk, typeof(*job), work); - - drm_sched_fence_scheduled(job->s_fence, NULL); - drm_sched_fence_finished(job->s_fence, -ESRCH); - WARN_ON(job->s_fence->parent); - job->sched->ops->free_job(job); -} - -/* Signal the scheduler finished fence when the entity in question is killed. */ -static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, - struct dma_fence_cb *cb) -{ - struct drm_sched_job *job = container_of(cb, struct drm_sched_job, - finish_cb); + struct dma_fence *f; unsigned long index; - dma_fence_put(f); - /* Wait for all dependencies to avoid data corruptions */ xa_for_each(&job->dependencies, index, f) { struct drm_sched_fence *s_fence = to_drm_sched_fence(f); @@ -220,6 +209,21 @@ static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, dma_fence_put(f); } + drm_sched_fence_scheduled(job->s_fence, NULL); + drm_sched_fence_finished(job->s_fence, -ESRCH); + WARN_ON(job->s_fence->parent); + job->sched->ops->free_job(job); +} + +/* Signal the scheduler finished fence when the entity in question is killed. */ +static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, + struct dma_fence_cb *cb) +{ + struct drm_sched_job *job = container_of(cb, struct drm_sched_job, + finish_cb); + + dma_fence_put(f); + INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work); schedule_work(&job->work); } -- 2.43.0

6 months, 2 weeks

Re: [PATCH v5 9/9] vfio/pci: Add dma-buf export support for MMIO regions

by Leon Romanovsky

On Wed, Oct 29, 2025, at 18:50, Alex Mastro wrote: > On Mon, Oct 13, 2025 at 06:26:11PM +0300, Leon Romanovsky wrote: >> + /* >> + * dma_buf_fd() consumes the reference, when the file closes the dmabuf >> + * will be released. >> + */ >> + return dma_buf_fd(priv->dmabuf, get_dma_buf.open_flags); > > I think this still needs to unwind state on fd allocation error. Reference > ownership is only transferred on success. Yes, you are correct, i need to call to dma_buf_put() in case of error. I will fix. Thanks > >> + >> +err_dev_put: >> + vfio_device_put_registration(&vdev->vdev); >> +err_free_phys: >> + kfree(priv->phys_vec); >> +err_free_priv: >> + kfree(priv); >> +err_free_ranges: >> + kfree(dma_ranges); >> + return ret; >> +}

6 months, 2 weeks

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