kvm: selftests: aarch64: dirty_log_test: fix unaligned memslot size

The memory slot size must be aligned to the host's page size. When
testing a guest with a 4k page size on a host with a 64k page size,
then 3 guest pages are not host page size aligned. Since we just need
a nearly arbitrary number of extra pages to ensure the memslot is not
aligned to a 64 host-page boundary for this test, then we can use
16, as that's 64k aligned, but not 64 * 64k aligned.

Fixes: 76d58e0f ("KVM: fix KVM_CLEAR_DIRTY_LOG for memory slots of unaligned size", 2019-04-17)
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/dirty_log_test.c

@@ -293,7 +293,7 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
 	 * A little more than 1G of guest page sized pages.  Cover the
 	 * case where the size is not aligned to 64 pages.
 	 */
-	guest_num_pages = (1ul << (30 - guest_page_shift)) + 3;
+	guest_num_pages = (1ul << (30 - guest_page_shift)) + 16;
 	host_page_size = getpagesize();
 	host_num_pages = (guest_num_pages * guest_page_size) / host_page_size +
 			 !!((guest_num_pages * guest_page_size) % host_page_size);