> +
> +static bool s390_bios_has_net_ccw(void)
> +{
Since you'll need to respin anyway...
Sorry, I think there was some confusion about what I asked for here.
AFAIU checking for this string is going to unconditionally work as long
as we enter netboot code, before we even decide if -ccw- or -pci support
is actually available. That's why you don't use this test for
virtio-net-pci.
Your old comment block said virtio-net-ccw support has always been there
(that's not strictly true)
So rather than removing the comment block, just reword it to explain
that the test just assumes virtio-net-ccw support is always available
and only checks that netboot started, it doesn't try to verify ccw support.
> + return s390_bios_has_string("Network boot starting...");
> +}
> +
> static testdef_t s390x_tests[] = {
> - { "s390-ccw-virtio", "virtio-net-ccw" },
> + { "s390-ccw-virtio", "virtio-net-ccw",
> + .boot_dev_support = s390_bios_has_net_ccw },
> { NULL },
> };
