list_replace_init cannot be used if the source is an empty list,
because "new->next->prev = new" will overwrite "old->next":
new old
prev = new, next = new prev = old, next = old
new->next = old->next prev = new, next = old prev = old, next = old
new->next->prev = new prev = new, next = old prev = old, next = new
new->prev = old->prev prev = old, next = old prev = old, next = old
new->next->prev = new prev = old, next = old prev = new, next = new
The desired outcome instead would be to leave both old and new the same
as they were (two empty circular lists). Use list_cut_before, which
already has the necessary check and is documented to discard the
previous contents of the list that will hold the result.
Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 21ac0a5de4e0..75955beb3770 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1613,8 +1613,7 @@ static void sev_migrate_from(struct kvm_sev_info *dst,
src->handle = 0;
src->pages_locked = 0;
- INIT_LIST_HEAD(&dst->regions_list);
- list_replace_init(&src->regions_list, &dst->regions_list);
+ list_cut_before(&dst->regions_list, &src->regions_list, &src->regions_list);
}
static int sev_es_migrate_from(struct kvm *dst, struct kvm *src)
--
2.27.0
