[PATCH 4/6] drm/amdkfd: Export DMABufs from KFD using GEM handles
Christian König
christian.koenig at amd.com
Fri Nov 17 16:30:05 UTC 2023
Am 16.11.23 um 22:53 schrieb Felix Kuehling:
>
> On 2023-11-07 11:58, Felix Kuehling wrote:
>> Create GEM handles for exporting DMABufs using GEM-Prime APIs. The GEM
>> handles are created in a drm_client_dev context to avoid exposing them
>> in user mode contexts through a DMABuf import.
> This patch (and the next one) won't apply upstream because Thomas
> Zimmerman just made drm_gem_prime_fd_to_handle and
> drm_gem_prime_handle_to_fd private because nobody was using them.
> (drm/prime: Unexport helpers for fd/handle conversion)
>
> Is it OK to export those APIs again? Or is there a better way for
> drivers to export/import DMABufs without using the GEM ioctls?
Well let me say so: I think it's the least evil approach :)
So yeah, propose a patch to export them again.
Regards,
Christian.
>
> Regards,
> Felix
>
>
>>
>> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 11 +++++++
>> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 5 +++
>> .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 33 +++++++++++++++----
>> drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 4 +--
>> 4 files changed, 44 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
>> index 6ab17330a6ed..b0a67f16540a 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
>> @@ -142,6 +142,7 @@ void amdgpu_amdkfd_device_init(struct
>> amdgpu_device *adev)
>> {
>> int i;
>> int last_valid_bit;
>> + int ret;
>> amdgpu_amdkfd_gpuvm_init_mem_limits();
>> @@ -160,6 +161,12 @@ void amdgpu_amdkfd_device_init(struct
>> amdgpu_device *adev)
>> .enable_mes = adev->enable_mes,
>> };
>> + ret = drm_client_init(&adev->ddev, &adev->kfd.client,
>> "kfd", NULL);
>> + if (ret) {
>> + dev_err(adev->dev, "Failed to init DRM client: %d\n", ret);
>> + return;
>> + }
>> +
>> /* this is going to have a few of the MSBs set that we need to
>> * clear
>> */
>> @@ -198,6 +205,10 @@ void amdgpu_amdkfd_device_init(struct
>> amdgpu_device *adev)
>> adev->kfd.init_complete = kgd2kfd_device_init(adev->kfd.dev,
>> &gpu_resources);
>> + if (adev->kfd.init_complete)
>> + drm_client_register(&adev->kfd.client);
>> + else
>> + drm_client_release(&adev->kfd.client);
>> amdgpu_amdkfd_total_mem_size += adev->gmc.real_vram_size;
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> index 68d534a89942..4caf8cece028 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> @@ -32,6 +32,7 @@
>> #include <linux/mmu_notifier.h>
>> #include <linux/memremap.h>
>> #include <kgd_kfd_interface.h>
>> +#include <drm/drm_client.h>
>> #include <drm/ttm/ttm_execbuf_util.h>
>> #include "amdgpu_sync.h"
>> #include "amdgpu_vm.h"
>> @@ -84,6 +85,7 @@ struct kgd_mem {
>> struct amdgpu_sync sync;
>> + uint32_t gem_handle;
>> bool aql_queue;
>> bool is_imported;
>> };
>> @@ -106,6 +108,9 @@ struct amdgpu_kfd_dev {
>> /* HMM page migration MEMORY_DEVICE_PRIVATE mapping */
>> struct dev_pagemap pgmap;
>> +
>> + /* Client for KFD BO GEM handle allocations */
>> + struct drm_client_dev client;
>> };
>> enum kgd_engine_type {
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> index 0c1cb6048259..4bb8b5fd7598 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> @@ -25,6 +25,7 @@
>> #include <linux/pagemap.h>
>> #include <linux/sched/mm.h>
>> #include <linux/sched/task.h>
>> +#include <linux/fdtable.h>
>> #include <drm/ttm/ttm_tt.h>
>> #include "amdgpu_object.h"
>> @@ -804,13 +805,22 @@ kfd_mem_dmaunmap_attachment(struct kgd_mem *mem,
>> static int kfd_mem_export_dmabuf(struct kgd_mem *mem)
>> {
>> if (!mem->dmabuf) {
>> - struct dma_buf *ret = amdgpu_gem_prime_export(
>> - &mem->bo->tbo.base,
>> + struct amdgpu_device *bo_adev;
>> + struct dma_buf *dmabuf;
>> + int r, fd;
>> +
>> + bo_adev = amdgpu_ttm_adev(mem->bo->tbo.bdev);
>> + r = drm_gem_prime_handle_to_fd(&bo_adev->ddev,
>> bo_adev->kfd.client.file,
>> + mem->gem_handle,
>> mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ?
>> - DRM_RDWR : 0);
>> - if (IS_ERR(ret))
>> - return PTR_ERR(ret);
>> - mem->dmabuf = ret;
>> + DRM_RDWR : 0, &fd);
>> + if (r)
>> + return r;
>> + dmabuf = dma_buf_get(fd);
>> + close_fd(fd);
>> + if (WARN_ON_ONCE(IS_ERR(dmabuf)))
>> + return PTR_ERR(dmabuf);
>> + mem->dmabuf = dmabuf;
>> }
>> return 0;
>> @@ -1826,6 +1836,9 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
>> pr_debug("Failed to allow vma node access. ret %d\n", ret);
>> goto err_node_allow;
>> }
>> + ret = drm_gem_handle_create(adev->kfd.client.file, gobj,
>> &(*mem)->gem_handle);
>> + if (ret)
>> + goto err_gem_handle_create;
>> bo = gem_to_amdgpu_bo(gobj);
>> if (bo_type == ttm_bo_type_sg) {
>> bo->tbo.sg = sg;
>> @@ -1877,6 +1890,8 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
>> err_pin_bo:
>> err_validate_bo:
>> remove_kgd_mem_from_kfd_bo_list(*mem, avm->process_info);
>> + drm_gem_handle_delete(adev->kfd.client.file, (*mem)->gem_handle);
>> +err_gem_handle_create:
>> drm_vma_node_revoke(&gobj->vma_node, drm_priv);
>> err_node_allow:
>> /* Don't unreserve system mem limit twice */
>> @@ -1991,8 +2006,12 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
>> /* Free the BO*/
>> drm_vma_node_revoke(&mem->bo->tbo.base.vma_node, drm_priv);
>> - if (mem->dmabuf)
>> + if (!mem->is_imported)
>> + drm_gem_handle_delete(adev->kfd.client.file, mem->gem_handle);
>> + if (mem->dmabuf) {
>> dma_buf_put(mem->dmabuf);
>> + mem->dmabuf = NULL;
>> + }
>> mutex_destroy(&mem->lock);
>> /* If this releases the last reference, it will end up calling
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
>> b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
>> index 06988cf1db51..4417a9863cd0 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
>> @@ -1855,8 +1855,8 @@ static uint32_t get_process_num_bos(struct
>> kfd_process *p)
>> return num_of_bos;
>> }
>> -static int criu_get_prime_handle(struct kgd_mem *mem, int flags,
>> - u32 *shared_fd)
>> +static int criu_get_prime_handle(struct kgd_mem *mem,
>> + int flags, u32 *shared_fd)
>> {
>> struct dma_buf *dmabuf;
>> int ret;
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