Am 2023-02-07 um 18:36 schrieb Chen, Xiaogang:
On 2/7/2023 2:48 PM, Felix Kuehling wrote:
Am 2023-02-07 um 15:35 schrieb Xiaogang.Chen:
From: Xiaogang Chen <xiaogang.chen@xxxxxxx>
When xnack is on user space can use svm page restore to set a vm
range without
setup it first, then use regular api to register. Currently kfd api
and svm are
not interoperable. We already have check on that, but for user
buffer the mapping
address is not same as buffer cpu virtual address. Add checking on
that to
avoid error propagate to hmm.
Signed-off-by: Xiaogang Chen <Xiaogang.Chen@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index f79b8e964140..cb7acb0b9b52 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1065,6 +1065,23 @@ static int
kfd_ioctl_alloc_memory_of_gpu(struct file *filep,
mutex_unlock(&p->svms.lock);
return -EADDRINUSE;
}
+
+ /* When register user buffer check if it has been registered by
svm by
+ * buffer cpu virtual address.
+ */
+ if (flags & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {
+
+ if (interval_tree_iter_first(&p->svms.objects,
+ untagged_addr(args->mmap_offset) >> PAGE_SHIFT,
+ (untagged_addr(args->mmap_offset) + args->size - 1)
>> PAGE_SHIFT)) {
Instead of nesting two if-blocks, you can write this as a single
if-block like
if ((flags & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) &&
interval_tree_iter_first(&p->svms.objects,
untagged_addr(args->mmap_offset) >> PAGE_SHIFT,
(untagged_addr(args->mmap_offset) + args->size
- 1) >> PAGE_SHIFT) {
I'm also not sure untagged_addr is needed here. If it is, we're
missing it in a bunch of other places too. Most notably, we don't
untag pointers anywhere in the SVM API.
memory virtual address tagging is architecture dependent. Ex: if
virtual address is 48bits and use 64bits pointer, people can use
additional bits for different purpose. From kernel source tree seems
only arm64 and sparc define untagged_addr that are not noop. For other
architectures it is defined as noop. I think we want have it if run on
different architecture cpu.
Fair enough. But it has to be consistent. If the SVM code fills the
interval tree with tagged addresses, we can't look for untagged
addresses here. Given that the SVM code currently uses (potentially)
tagged addresses, we should not use untagged addresses here. A proper
fix for untagging addresses in the SVM code would be needed as a
separate commit.
Regards,
Felix
Regards,
Felix
+
+ pr_err("User Buffer Address: 0x%llx already allocated
by SVM\n",
+ untagged_addr(args->mmap_offset));
+ mutex_unlock(&p->svms.lock);
+ return -EADDRINUSE;
+ }
+
+ }
mutex_unlock(&p->svms.lock);
#endif
mutex_lock(&p->mutex);
