diff options
| author | Emily Deng <Emily.Deng@amd.com> | 2025-03-06 08:40:01 +0800 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2025-03-13 23:10:16 -0400 |
| commit | f844732e3ad9c4b78df7436232949b8d2096d1a6 (patch) | |
| tree | 97bbb9b221dcec7b77fc845c362f35bedac43bc2 | |
| parent | b9e75bcb2b39e1202364d958ee4f27fd8a6f1313 (diff) | |
drm/amdgpu: Fix the race condition for draining retry fault
Issue:
In the scenario where svm_range_restore_pages is called, but
svm->checkpoint_ts has not been set and the retry fault has not been
drained, svm_range_unmap_from_cpu is triggered and calls svm_range_free.
Meanwhile, svm_range_restore_pages continues execution and reaches
svm_range_from_addr. This results in a "failed to find prange..." error,
causing the page recovery to fail.
How to fix:
Move the timestamp check code under the protection of svm->lock.
v2:
Make sure all right locks are released before go out.
v3:
Directly goto out_unlock_svms, and return -EAGAIN.
v4:
Refine code.
Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 1a38ac75abbd..63eeef2a75ba 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -3009,19 +3009,6 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid, goto out; } - /* check if this page fault time stamp is before svms->checkpoint_ts */ - if (svms->checkpoint_ts[gpuidx] != 0) { - if (amdgpu_ih_ts_after_or_equal(ts, svms->checkpoint_ts[gpuidx])) { - pr_debug("draining retry fault, drop fault 0x%llx\n", addr); - r = 0; - goto out; - } else - /* ts is after svms->checkpoint_ts now, reset svms->checkpoint_ts - * to zero to avoid following ts wrap around give wrong comparing - */ - svms->checkpoint_ts[gpuidx] = 0; - } - if (!p->xnack_enabled) { pr_debug("XNACK not enabled for pasid 0x%x\n", pasid); r = -EFAULT; @@ -3041,6 +3028,21 @@ svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid, mmap_read_lock(mm); retry_write_locked: mutex_lock(&svms->lock); + + /* check if this page fault time stamp is before svms->checkpoint_ts */ + if (svms->checkpoint_ts[gpuidx] != 0) { + if (amdgpu_ih_ts_after_or_equal(ts, svms->checkpoint_ts[gpuidx])) { + pr_debug("draining retry fault, drop fault 0x%llx\n", addr); + r = -EAGAIN; + goto out_unlock_svms; + } else { + /* ts is after svms->checkpoint_ts now, reset svms->checkpoint_ts + * to zero to avoid following ts wrap around give wrong comparing + */ + svms->checkpoint_ts[gpuidx] = 0; + } + } + prange = svm_range_from_addr(svms, addr, NULL); if (!prange) { pr_debug("failed to find prange svms 0x%p address [0x%llx]\n", @@ -3166,7 +3168,8 @@ out_unlock_svms: mutex_unlock(&svms->lock); mmap_read_unlock(mm); - svm_range_count_fault(node, p, gpuidx); + if (r != -EAGAIN) + svm_range_count_fault(node, p, gpuidx); mmput(mm); out: |