On 2026/5/13 上午7:41, Sean Christopherson wrote:
On Fri, May 08, 2026, Bibo Mao wrote:
The type of guest_memfd in structure kvm_userspace_memory_region2
is __u32, it is not correct to assign it with -1 and check whether
it is smaller than 0. Here check flags with KVM_MEM_GUEST_MEMFD
set.
Signed-off-by: Bibo Mao <[email protected]>
---
tools/testing/selftests/kvm/lib/kvm_util.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c
b/tools/testing/selftests/kvm/lib/kvm_util.c
index 2a76eca7029d..9d3553f7e6a5 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -817,7 +817,7 @@ static void __vm_mem_region_delete(struct kvm_vm *vm,
kvm_munmap(region->mmap_alias, region->mmap_size);
close(region->fd);
}
- if (region->region.guest_memfd >= 0)
+ if (region->region.flags & KVM_MEM_GUEST_MEMFD)
Hmm, it's a bit gross, but this is probably more robust?
if ((int)region->region.guest_memfd < 0)
yes, this is more direct, only that some guys in the community do not
like type conversion. Both are ok for me.
E.g. if we somehow end up in a state where KVM_MEM_GUEST_MEMFD is either stale
or the guest_memfd file was already closed. I highly doubt either of those
things
will happen, but logically it's the correct fix (the only reason guest_memfd is
a u32 is being it's part of the kernel's uAPI).
Actually it probably will happen, how about something like this:
- if (region->region.guest_memfd >= 0)
+ if ((int)region->region.guest_memfd >= 0) {
close(region->region.guest_memfd);
+ region->region.guest_memfd = -1;
+ }
Regards
Bibo Mao
