KVM: SEV: do not use list_replace_init on an empty list
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")
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211123005036.2954379-5-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed