Linaro-mm-sig November 2025

linaro-mm-sig@lists.linaro.org

70 participants
54 discussions

[PATCH v3 00/28] 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) For v3 I've kept the series as a whole but I've reorganized the patches so that everything up to the drm/ttm change can be merged through amd-staging-drm-next once reviewed. v3: - shuffled the patches: everything up to the drm/ttm patch has no dependency on the ttm change and be merged independently - split "drm/amdgpu: pass the entity to use to ttm functions" in 2 commits - moved AMDGPU_GTT_NUM_TRANSFER_WINDOWS removal to its own commit - added a ttm job submission helper - addressed comments from Christian and Felix v2: - addressed comments from Christian - dropped "drm/amdgpu: prepare amdgpu_fill_buffer to use N entities" and "drm/amdgpu: use multiple entities in amdgpu_fill_buffer" - added "drm/admgpu: handle resv dependencies in amdgpu_ttm_map_buffer", "drm/amdgpu: round robin through clear_entities in amdgpu_fill_buffer" - reworked how sdma rings/scheds are passed to amdgpu_ttm v1: https://lists.freedesktop.org/archives/dri-devel/2025-November/534517.html Pierre-Eric Pelloux-Prayer (28): drm/amdgpu: give each kernel job a unique id drm/amdgpu: use ttm_resource_manager_cleanup drm/amdgpu: remove direct_submit arg from amdgpu_copy_buffer drm/amdgpu: remove the ring param from ttm functions drm/amdgpu: introduce amdgpu_ttm_buffer_entity drm/amdgpu: add amdgpu_ttm_job_submit helper drm/amdgpu: fix error handling in amdgpu_copy_buffer drm/amdgpu: pass the entity to use to amdgpu_ttm_map_buffer drm/amdgpu: pass the entity to use to ttm public functions drm/amdgpu: add amdgpu_device argument to ttm functions that need it drm/amdgpu: statically assign gart windows to ttm entities drm/amdgpu: remove AMDGPU_GTT_NUM_TRANSFER_WINDOWS drm/amdgpu: add missing lock when using ttm entities drm/amdgpu: check entity lock is held in amdgpu_ttm_job_submit drm/amdgpu: double AMDGPU_GTT_MAX_TRANSFER_SIZE drm/amdgpu: use larger gart window when possible drm/amdgpu: introduce amdgpu_sdma_set_vm_pte_scheds drm/amdgpu: move sched status check inside amdgpu_ttm_set_buffer_funcs_status drm/ttm: rework pipelined eviction fence handling drm/amdgpu: allocate multiple clear entities drm/amdgpu: allocate multiple move entities drm/amdgpu: round robin through clear_entities in amdgpu_fill_buffer drm/amdgpu: use TTM_NUM_MOVE_FENCES when reserving fences drm/amdgpu: use multiple entities in amdgpu_move_blit drm/amdgpu: pass all the sdma scheds to amdgpu_mman 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_ttm_clear_buffer drivers/gpu/drm/amd/amdgpu/amdgpu.h | 4 + drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c | 8 +- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 5 +- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 15 +- 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 | 14 +- drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 8 +- 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 | 16 +- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 493 +++++++++++------- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 58 ++- drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c | 3 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c | 11 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vce.h | 3 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.c | 8 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c | 6 +- drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 26 +- 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 | 34 +- drivers/gpu/drm/amd/amdgpu/sdma_v2_4.c | 34 +- drivers/gpu/drm/amd/amdgpu/sdma_v3_0.c | 34 +- drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 41 +- drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c | 41 +- drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c | 37 +- drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c | 37 +- drivers/gpu/drm/amd/amdgpu/sdma_v6_0.c | 32 +- drivers/gpu/drm/amd/amdgpu/sdma_v7_0.c | 32 +- drivers/gpu/drm/amd/amdgpu/si_dma.c | 34 +- drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c | 6 +- drivers/gpu/drm/amd/amdgpu/uvd_v7_0.c | 6 +- drivers/gpu/drm/amd/amdgpu/vce_v1_0.c | 12 +- drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 33 +- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 3 +- .../amd/display/amdgpu_dm/amdgpu_dm_plane.c | 6 +- .../drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c | 6 +- .../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 +- 47 files changed, 706 insertions(+), 615 deletions(-) -- 2.43.0

7 months, 3 weeks

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

by Barry Song

From: Barry Song <v-songbaohua(a)oppo.com> We can allocate high-order pages, but mapping them one by one is inefficient. This patch changes the code to map as large a chunk as possible. The code looks somewhat complicated mainly because supporting mmap with a non-zero offset is a bit tricky. Using the micro-benchmark below, we see that mmap becomes 3.5X faster: #include <stdio.h> #include <fcntl.h> #include <linux/dma-heap.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <time.h> #include <unistd.h> #include <stdlib.h> #define SIZE (512UL * 1024 * 1024) #define PAGE 4096 #define STRIDE (PAGE/sizeof(int)) #define PAGES (SIZE/PAGE) int main(void) { int heap = open("/dev/dma_heap/system", O_RDONLY); struct dma_heap_allocation_data d = { .len = SIZE, .fd_flags = O_RDWR|O_CLOEXEC }; ioctl(heap, DMA_HEAP_IOCTL_ALLOC, &d); struct timespec t0, t1; clock_gettime(CLOCK_MONOTONIC, &t0); int *p = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, d.fd, 0); clock_gettime(CLOCK_MONOTONIC, &t1); for (int i = 0; i < PAGES; i++) p[i*STRIDE] = i; for (int i = 0; i < PAGES; i++) if (p[i*STRIDE] != i) { fprintf(stderr, "mismatch at page %d\n", i); exit(1); } long ns = (t1.tv_sec-t0.tv_sec)*1000000000L + (t1.tv_nsec-t0.tv_nsec); printf("mmap 512MB took %.3f us, verify OK\n", ns/1000.0); return 0; } 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 Signed-off-by: Barry Song <v-songbaohua(a)oppo.com> Acked-by: John Stultz <jstultz(a)google.com> --- -v2: collect John's ack. thanks! drivers/dma-buf/heaps/system_heap.c | 33 +++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 9 deletions(-) diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c index bbe7881f1360..4c782fe33fd4 100644 --- a/drivers/dma-buf/heaps/system_heap.c +++ b/drivers/dma-buf/heaps/system_heap.c @@ -186,20 +186,35 @@ static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma) struct system_heap_buffer *buffer = dmabuf->priv; struct sg_table *table = &buffer->sg_table; unsigned long addr = vma->vm_start; - struct sg_page_iter piter; - int ret; + unsigned long pgoff = vma->vm_pgoff; + struct scatterlist *sg; + int i, ret; + + for_each_sgtable_sg(table, sg, i) { + unsigned long n = sg->length >> PAGE_SHIFT; - for_each_sgtable_page(table, &piter, vma->vm_pgoff) { - struct page *page = sg_page_iter_page(&piter); + if (pgoff < n) + break; + pgoff -= n; + } + + for (; sg && addr < vma->vm_end; sg = sg_next(sg)) { + unsigned long n = (sg->length >> PAGE_SHIFT) - pgoff; + struct page *page = sg_page(sg) + pgoff; + unsigned long size = n << PAGE_SHIFT; + + if (addr + size > vma->vm_end) + size = vma->vm_end - addr; - ret = remap_pfn_range(vma, addr, page_to_pfn(page), PAGE_SIZE, - vma->vm_page_prot); + ret = remap_pfn_range(vma, addr, page_to_pfn(page), + size, vma->vm_page_prot); if (ret) return ret; - addr += PAGE_SIZE; - if (addr >= vma->vm_end) - return 0; + + addr += size; + pgoff = 0; } + return 0; } -- 2.39.3 (Apple Git-146)

7 months, 3 weeks

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

7 months, 3 weeks

[PATCH 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/r/20251106-dmabuf-vfio-v7-0-2503bf390699@nvidia.com 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 v7 - Fix mislocking in an iopt_fill_domain() error path 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 | 53 ++- 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 | 407 ++++++++++++++++-- drivers/iommu/iommufd/selftest.c | 142 ++++++ 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, 781 insertions(+), 66 deletions(-) base-commit: bb04e92c86b44b3e36532099b68de1e889acfee7 -- 2.43.0

7 months, 3 weeks

Re: [PATCH v9 11/11] vfio/nvgrace: Support get_dmabuf_phys

by ankita＠nvidia.com

The content of this message was lost. It was probably cross-posted to multiple lists and previously handled on another list.

7 months, 3 weeks

[PATCH] drm/xe: Fix memory leak when handling pagefault vma

by Mika Kuoppala

When the pagefault handling code was moved to a new file, an extra drm_exec_init() was added to the VMA path. This call is unnecessary because xe_validation_ctx_init() already performs a drm_exec_init(), resulting in a memory leak reported by kmemleak. Remove the redundant drm_exec_init() from the VMA pagefault handling code. Fixes: fb544b844508 ("drm/xe: Implement xe_pagefault_queue_work") Cc: Matthew Brost <matthew.brost(a)intel.com> Cc: Stuart Summers <stuart.summers(a)intel.com> Cc: Lucas De Marchi <lucas.demarchi(a)intel.com> Cc: "Thomas Hellström" <thomas.hellstrom(a)linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi(a)intel.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: intel-xe(a)lists.freedesktop.org Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Signed-off-by: Mika Kuoppala <mika.kuoppala(a)linux.intel.com> --- drivers/gpu/drm/xe/xe_pagefault.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_pagefault.c b/drivers/gpu/drm/xe/xe_pagefault.c index fe3e40145012..afb06598b6e1 100644 --- a/drivers/gpu/drm/xe/xe_pagefault.c +++ b/drivers/gpu/drm/xe/xe_pagefault.c @@ -102,7 +102,6 @@ static int xe_pagefault_handle_vma(struct xe_gt *gt, struct xe_vma *vma, /* Lock VM and BOs dma-resv */ xe_validation_ctx_init(&ctx, &vm->xe->val, &exec, (struct xe_val_flags) {}); - drm_exec_init(&exec, 0, 0); drm_exec_until_all_locked(&exec) { err = xe_pagefault_begin(&exec, vma, tile->mem.vram, needs_vram == 1); -- 2.43.0

7 months, 3 weeks

[RFC PATCH 0/2] locking/ww_mutex, dma-buf/dma-resv: Improve detection of unheld locks

by Thomas Hellström

WW mutexes and dma-resv objects, which embed them, typically have a number of locks belocking to the same lock class. However code using them typically want to verify the locking on object granularity, not lock-class granularity. This series add ww_mutex functions to facilitate that, (patch 1) and utilizes these functions in the dma-resv lock checks. Thomas Hellström (2): kernel/locking/ww_mutex: Add per-lock lock-check helpers dma-buf/dma-resv: Improve the dma-resv lockdep checks include/linux/dma-resv.h | 7 +++++-- include/linux/ww_mutex.h | 18 ++++++++++++++++++ kernel/locking/mutex.c | 10 ++++++++++ 3 files changed, 33 insertions(+), 2 deletions(-) -- 2.51.1

7 months, 3 weeks

[PATCH v3 00/21] treewide: Introduce %ptS for struct timespec64 and convert users

by Andy Shevchenko

Here is the third part of the unification time printing in the kernel. This time for struct timespec64. The first patch brings a support into printf() implementation (test cases and documentation update included) followed by the treewide conversion of the current users. Petr, we got like more than a half being Acked, I think if you are okay with this, the patches that have been tagged can be applied. Note, not everything was compile-tested. Kunit test has been passed, though. Changelog v3: - fixed a compilation issue with fnic (LKP), also satisfied checkpatch - collected more tags Petr, I have not renamed 'p' to 'n' due to much of rework and noise introduction for the changes that has been reviewed. However, I addressed the documentation issues. v2: <20251111122735.880607-1-andriy.shevchenko(a)linux.intel.com> Changelog v2: - dropped wrong patches (Hans, Takashi) - fixed most of the checkpatch warnings (fdo CI, media CI) - collected tags v1: <20251110184727.666591-1-andriy.shevchenko(a)linux.intel.com> Andy Shevchenko (21): lib/vsprintf: Add specifier for printing struct timespec64 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 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 %ptSp 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/mmc/core/mmc_test.c | 20 +++---- 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 | 13 ++--- drivers/s390/block/dasd.c | 3 +- drivers/scsi/fnic/fnic_trace.c | 52 ++++++++----------- 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 | 49 ++++++----------- fs/ceph/xattr.c | 6 +-- kernel/trace/trace_output.c | 6 +-- lib/tests/printf_kunit.c | 4 ++ lib/vsprintf.c | 28 +++++++++- net/ceph/messenger_v2.c | 6 +-- 29 files changed, 130 insertions(+), 153 deletions(-) -- 2.50.1

7 months, 3 weeks

[PATCH v8 00/11] vfio/pci: Allow MMIO regions to be exported through dma-buf

by Leon Romanovsky

Changelog: v8: * Fixed spelling errors in p2pdma documentation file. * Added vdev->pci_ops check for NULL in vfio_pci_core_feature_dma_buf(). * Simplified the nvgrace_get_dmabuf_phys() function. * Added extra check in pcim_p2pdma_provider() to catch missing call to pcim_p2pdma_init(). v7: https://patch.msgid.link/20251106-dmabuf-vfio-v7-0-2503bf390699@nvidia.com * Dropped restore_revoke flag and added vfio_pci_dma_buf_move to reverse loop. * Fixed spelling errors in documentation patch. * Rebased on top of v6.18-rc3. * Added include to stddef.h to vfio.h, to keep uapi header file independent. v6: https://patch.msgid.link/20251102-dmabuf-vfio-v6-0-d773cff0db9f@nvidia.com * Fixed wrong error check from pcim_p2pdma_init(). * Documented pcim_p2pdma_provider() function. * Improved commit messages. * Added VFIO DMA-BUF selftest, not sent yet. * Added __counted_by(nr_ranges) annotation to struct vfio_device_feature_dma_buf. * Fixed error unwind when dma_buf_fd() fails. * Document latest changes to p2pmem. * Removed EXPORT_SYMBOL_GPL from pci_p2pdma_map_type. * Moved DMA mapping logic to DMA-BUF. * Removed types patch to avoid dependencies between subsystems. * Moved vfio_pci_dma_buf_move() in err_undo block. * Added nvgrace patch. v5: https://lore.kernel.org/all/cover.1760368250.git.leon@kernel.org * 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 --- Jason Gunthorpe (2): PCI/P2PDMA: Document DMABUF model vfio/nvgrace: Support get_dmabuf_phys 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: Provide an access to pci_p2pdma_map_type() function dma-buf: provide phys_vec to scatter-gather mapping routine 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 Documentation/driver-api/pci/p2pdma.rst | 95 +++++++--- block/blk-mq-dma.c | 2 +- drivers/dma-buf/dma-buf.c | 235 ++++++++++++++++++++++++ drivers/iommu/dma-iommu.c | 4 +- drivers/pci/p2pdma.c | 186 ++++++++++++++----- drivers/vfio/pci/Kconfig | 3 + drivers/vfio/pci/Makefile | 1 + drivers/vfio/pci/nvgrace-gpu/main.c | 56 ++++++ drivers/vfio/pci/vfio_pci.c | 5 + drivers/vfio/pci/vfio_pci_config.c | 22 ++- drivers/vfio/pci/vfio_pci_core.c | 53 ++++-- drivers/vfio/pci/vfio_pci_dmabuf.c | 315 ++++++++++++++++++++++++++++++++ drivers/vfio/pci/vfio_pci_priv.h | 23 +++ drivers/vfio/vfio_main.c | 2 + include/linux/dma-buf.h | 18 ++ include/linux/pci-p2pdma.h | 120 +++++++----- include/linux/vfio.h | 2 + include/linux/vfio_pci_core.h | 42 +++++ include/uapi/linux/vfio.h | 28 +++ kernel/dma/direct.c | 4 +- mm/hmm.c | 2 +- 21 files changed, 1078 insertions(+), 140 deletions(-) --- base-commit: dcb6fa37fd7bc9c3d2b066329b0d27dedf8becaa change-id: 20251016-dmabuf-vfio-6cef732adf5a Best regards, -- Leon Romanovsky <leonro(a)nvidia.com>

7 months, 3 weeks

Re: [PATCH] rust: bindings: add `rust_helper_wait_for_completion` helper function

by Boqun Feng

On Thu, Oct 02, 2025 at 10:06:17AM +0000, Guangbo Cui wrote: > > -extern void wait_for_completion(struct completion *); > > -extern void wait_for_completion_io(struct completion *); > > -extern int wait_for_completion_interruptible(struct completion *x); > > -extern int wait_for_completion_killable(struct completion *x); > > -extern int wait_for_completion_state(struct completion *x, unsigned int state); > > -extern unsigned long wait_for_completion_timeout(struct completion *x, > > +extern void __wait_for_completion(struct completion *); > > +extern void __wait_for_completion_io(struct completion *); > > +extern int __wait_for_completion_interruptible(struct completion *x); > > +extern int __wait_for_completion_killable(struct completion *x); > > +extern int __wait_for_completion_state(struct completion *x, unsigned int state); > > +extern unsigned long __wait_for_completion_timeout(struct completion *x, > > unsigned long timeout); > > -extern unsigned long wait_for_completion_io_timeout(struct completion *x, > > +extern unsigned long __wait_for_completion_io_timeout(struct completion *x, > > unsigned long timeout); > > -extern long wait_for_completion_interruptible_timeout( > > +extern long __wait_for_completion_interruptible_timeout( > > struct completion *x, unsigned long timeout); > > -extern long wait_for_completion_killable_timeout( > > +extern long __wait_for_completion_killable_timeout( > > struct completion *x, unsigned long timeout); > > extern bool try_wait_for_completion(struct completion *x); > > extern bool completion_done(struct completion *x); > > @@ -139,4 +134,79 @@ extern void complete(struct completion *); > > extern void complete_on_current_cpu(struct completion *x); > > extern void complete_all(struct completion *); > > > > +#define wait_for_completion(x) \ > > +({ \ > > + sdt_might_sleep_start_timeout(NULL, -1L); \ > > + __wait_for_completion(x); \ > > + sdt_might_sleep_end(); \ > > +}) > > The DEPT patch series changed `wait_for_completion` into a macro. > Because bindgen cannot handle function-like macros, this caused > Rust build errors. Add a helper function to fix it. > > ``` > error[E0425]: cannot find function `wait_for_completion` in crate `bindings` > --> rust/kernel/sync/completion.rs:110:28 > | > 110 | unsafe { bindings::wait_for_completion(self.as_raw()) }; > | ^^^^^^^^^^^^^^^^^^^ help: a function with a similar name exists: `__wait_for_completion` > | > ::: /root/linux/rust/bindings/bindings_generated.rs:33440:5 > | > 33440 | pub fn __wait_for_completion(arg1: *mut completion); > | ---------------------------------------------------- similarly named function `__wait_for_completion` defined here > > error: aborting due to 1 previous error > > For more information about this error, try `rustc --explain E0425`. > ``` > I think Danilo already made it clear, please fold this the existing patch. Moreover, since this patchset doesn't adjust init_completion() from the Rust side, the result is Rust code will also use the same dept key for completion, which has to be fixed if dept wants to be in-tree. Regards, Boqun > Signed-off-by: Guangbo Cui <2407018371(a)qq.com> > --- > rust/helpers/completion.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/rust/helpers/completion.c b/rust/helpers/completion.c > index b2443262a2ae..5bae5e749def 100644 > --- a/rust/helpers/completion.c > +++ b/rust/helpers/completion.c > @@ -6,3 +6,8 @@ void rust_helper_init_completion(struct completion *x) > { > init_completion(x); > } > + > +void rust_helper_wait_for_completion(struct completion *x) > +{ > + wait_for_completion(x); > +} > -- > 2.43.0 >

7 months, 4 weeks

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Linaro-mm-sig November 2025