On 5/7/26 16:09, Yifan Zhang wrote: > During Mode 1 reset, the ASIC undergoes a reset cycle and becomes temporarily > inaccessible via PCIe. Any attempt to access framebuffer or MMIO registers > during > this window can result in uncompleted PCIe transactions, leading to NMI > panics or > system hangs. > > To prevent this, Unmap all of the applications mappings of the framebuffer > and doorbell BARs before mode1 reset. Also prevent new mappings from coming in > during the reset process.
I think putting the inode into the kfd_dev would break userspace, so that is a no-go and needs a different solution. But apart from that the patch looks like what I suggested before. Question is since when does that issue exists? Previously we didn't had to take care of that. Regards, Christian. > > Signed-off-by: Yifan Zhang <[email protected]> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 1 + > .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 12 ++++++++++++ > drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 7 ++++++- > drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 17 +++++++++++++++-- > drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 10 ++++++++++ > drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 3 +++ > 6 files changed, 47 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h > b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h > index 2bf6a31c194d..5333e052d56d 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h > @@ -360,6 +360,7 @@ int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device > *adev, > uint64_t size, u32 alloc_flag, int8_t xcp_id); > void amdgpu_amdkfd_unreserve_mem_limit(struct amdgpu_device *adev, > uint64_t size, u32 alloc_flag, int8_t xcp_id); > +void amdgpu_amdkfd_clear_kfd_mapping(struct amdgpu_device *adev); > > u64 amdgpu_amdkfd_xcp_memory_size(struct amdgpu_device *adev, int xcp_id); > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c > index 7c01492e69dd..3ac2bd86c08b 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c > @@ -139,6 +139,18 @@ void amdgpu_amdkfd_reserve_system_mem(uint64_t size) > kfd_mem_limit.system_mem_used += size; > } > > +void amdgpu_amdkfd_clear_kfd_mapping(struct amdgpu_device *adev) > +{ > + if (adev->kfd.dev && adev->kfd.dev->inode && > + adev->kfd.dev->inode->i_mapping) { > + unmap_mapping_range(adev->kfd.dev->inode->i_mapping, > + KFD_MMAP_TYPE_DOORBELL, > kfd_doorbell_process_slice(adev->kfd.dev), 1); > + unmap_mapping_range(adev->kfd.dev->inode->i_mapping, > + KFD_MMAP_TYPE_MMIO, PAGE_SIZE, 1); > + } > +} > + > + > /* Estimate page table size needed to represent a given memory size > * > * With 4KB pages, we need one 8 byte PTE for each 4KB of memory > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > index 073f632f295a..c67936d1fb0d 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c > @@ -5019,7 +5019,6 @@ int amdgpu_device_mode1_reset(struct amdgpu_device > *adev) > > /* disable BM */ > pci_clear_master(adev->pdev); > - > if (amdgpu_dpm_is_mode1_reset_supported(adev)) { > dev_info(adev->dev, "GPU smu mode1 reset\n"); > ret = amdgpu_dpm_mode1_reset(adev); > @@ -5840,6 +5839,12 @@ int amdgpu_device_gpu_recover(struct amdgpu_device > *adev, > /* We need to lock reset domain only once both for XGMI and single > device */ > amdgpu_device_recovery_get_reset_lock(adev, &device_list); > > + /* unmap all the mappings of doorbell and framebuffer to prevent user > space from > + * accessing them > + */ > + unmap_mapping_range(adev->ddev.anon_inode->i_mapping, 0, 0, 1); > + amdgpu_amdkfd_clear_kfd_mapping(adev); > + > amdgpu_device_halt_activities(adev, job, reset_context, &device_list, > hive, need_emergency_restart); > if (need_emergency_restart) > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > index 0071d6957828..1dd343f0219f 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c > @@ -46,6 +46,7 @@ > #include "amdgpu_hmm.h" > #include "amdgpu_xgmi.h" > #include "amdgpu_vm.h" > +#include "amdgpu_reset.h" > > static int > amdgpu_gem_add_input_fence(struct drm_file *filp, > @@ -118,13 +119,21 @@ amdgpu_gem_update_timeline_node(struct drm_file *filp, > static vm_fault_t amdgpu_gem_fault(struct vm_fault *vmf) > { > struct ttm_buffer_object *bo = vmf->vma->vm_private_data; > + struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev); > struct drm_device *ddev = bo->base.dev; > vm_fault_t ret; > int idx; > > + /* Prevent new mappings from coming in during reset */ > + > + if (!down_read_trylock(&adev->reset_domain->sem)) > + return VM_FAULT_SIGSEGV; > + > ret = ttm_bo_vm_reserve(bo, vmf); > - if (ret) > + if (ret) { > + up_read(&adev->reset_domain->sem); > return ret; > + } > > if (drm_dev_enter(ddev, &idx)) { > ret = amdgpu_bo_fault_reserve_notify(bo); > @@ -140,11 +149,15 @@ static vm_fault_t amdgpu_gem_fault(struct vm_fault *vmf) > } else { > ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot); > } > - if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) > + if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { > + up_read(&adev->reset_domain->sem); > return ret; > + } > > unlock: > dma_resv_unlock(bo->base.resv); > + up_read(&adev->reset_domain->sem); > + > return ret; > } > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c > b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c > index 84b9bde7f371..d5bf5ba73ca0 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c > @@ -130,11 +130,21 @@ void kfd_chardev_exit(void) > static int kfd_open(struct inode *inode, struct file *filep) > { > struct kfd_process *process; > + struct kfd_node *node; > bool is_32bit_user_mode; > + int i; > > if (iminor(inode) != 0) > return -ENODEV; > > + /* Save inode in kfd_dev for unmap_mapping_range */ > + for (i = 0; kfd_topology_enum_kfd_devices(i, &node) == 0; i++) { > + if (node && node->kfd && !node->kfd->inode) { > + node->kfd->inode = inode; > + break; > + } > + } > + > is_32bit_user_mode = in_compat_syscall(); > > if (is_32bit_user_mode) { > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h > b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h > index a6ff1db477f9..bfdd7d3bc7cb 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h > @@ -373,6 +373,9 @@ struct kfd_dev { > > struct workqueue_struct *ih_wq; > > + /* kfd inode */ > + struct inode *inode; > + > /* Kernel doorbells for KFD device */ > struct amdgpu_bo *doorbells; >
