amd/amdkfd: Trigger segfault for early userptr unmmapping

If applications unmap the memory before destroying the userptr, it needs
trigger a segfault to notify user space to correct the free sequence in
VM debug mode.

v2: Send gpu access fault to user space
v3: Report gpu address to user space, remove unnecessary params
v4: update pr_err into one line, remove userptr log info

Signed-off-by: Shane Xiao <shane.xiao@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Shane Xiao 2025-04-23 17:28:50 +08:00 committed by Alex Deucher
parent 8e320f67d4
commit 2d274bf709
3 changed files with 33 additions and 0 deletions

View file

@ -2559,6 +2559,18 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info,
if (ret != -EFAULT) if (ret != -EFAULT)
return ret; return ret;
/* If applications unmap memory before destroying the userptr
* from the KFD, trigger a segmentation fault in VM debug mode.
*/
if (amdgpu_ttm_adev(bo->tbo.bdev)->debug_vm_userptr) {
pr_err("Pid %d unmapped memory before destroying userptr at GPU addr 0x%llx\n",
pid_nr(process_info->pid), mem->va);
// Send GPU VM fault to user space
kfd_signal_vm_fault_event_with_userptr(kfd_lookup_process_by_pid(process_info->pid),
mem->va);
}
ret = 0; ret = 0;
} }

View file

@ -1177,6 +1177,25 @@ void kfd_signal_hw_exception_event(u32 pasid)
kfd_unref_process(p); kfd_unref_process(p);
} }
void kfd_signal_vm_fault_event_with_userptr(struct kfd_process *p, uint64_t gpu_va)
{
struct kfd_process_device *pdd;
struct kfd_hsa_memory_exception_data exception_data;
int i;
memset(&exception_data, 0, sizeof(exception_data));
exception_data.va = gpu_va;
exception_data.failure.NotPresent = 1;
// Send VM seg fault to all kfd process device
for (i = 0; i < p->n_pdds; i++) {
pdd = p->pdds[i];
exception_data.gpu_id = pdd->user_gpu_id;
kfd_evict_process_device(pdd);
kfd_signal_vm_fault_event(pdd, NULL, &exception_data);
}
}
void kfd_signal_vm_fault_event(struct kfd_process_device *pdd, void kfd_signal_vm_fault_event(struct kfd_process_device *pdd,
struct kfd_vm_fault_info *info, struct kfd_vm_fault_info *info,
struct kfd_hsa_memory_exception_data *data) struct kfd_hsa_memory_exception_data *data)

View file

@ -1507,6 +1507,8 @@ int kfd_event_create(struct file *devkfd, struct kfd_process *p,
int kfd_get_num_events(struct kfd_process *p); int kfd_get_num_events(struct kfd_process *p);
int kfd_event_destroy(struct kfd_process *p, uint32_t event_id); int kfd_event_destroy(struct kfd_process *p, uint32_t event_id);
void kfd_signal_vm_fault_event_with_userptr(struct kfd_process *p, uint64_t gpu_va);
void kfd_signal_vm_fault_event(struct kfd_process_device *pdd, void kfd_signal_vm_fault_event(struct kfd_process_device *pdd,
struct kfd_vm_fault_info *info, struct kfd_vm_fault_info *info,
struct kfd_hsa_memory_exception_data *data); struct kfd_hsa_memory_exception_data *data);