From: Zongyao Chen <[email protected]>
KVM_SET_USER_MEMORY_REGION2 rejects guest_memfd ranges that overlap an
existing binding, but kvm_gmem_bind() currently reports the failure through
its generic -EINVAL path. That makes binding conflicts indistinguishable
from malformed guest_memfd parameters.
Return -EEXIST when the target guest_memfd range is already bound, matching
the errno used for overlapping GPA memslots and making the two types of
range conflicts report the same class of error to userspace.
Fixes: a7800aa80ea4 ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for
guest-specific backing memory")
Signed-off-by: Zongyao Chen <[email protected]>
---
virt/kvm/guest_memfd.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 69c9d6d546b2..46727539d08a 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -675,6 +675,7 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_slot
*slot,
if (!xa_empty(&f->bindings) &&
xa_find(&f->bindings, &start, end - 1, XA_PRESENT)) {
+ r = -EEXIST;
filemap_invalidate_unlock(inode->i_mapping);
goto err;
}
--
2.47.3
