On Fri, 2023-09-01 at 11:48 +0000, Janosch Frank wrote:
> Bound APQNs have to be reset before tearing down the secure config via
> s390_machine_unprotect(). Otherwise the Ultravisor will return a error
> code.
>
> So let's do a subsystem_reset() which includes a AP reset before the
> unprotect call. We'll do a full device_reset() afterwards which will
> reset some devices twice. That's ok since we can't move the
> device_reset() before the unprotect as it includes a CPU clear reset
> which the Ultravisor does not expect at that point in time.
>
> Signed-off-by: Janosch Frank <fran...@linux.ibm.com>
> ---
>
> I'm not able to test this for the PV AP case right new, that has to
> wait to early next week. However Marc told me that the non-AP PV test
> works fine now.
>
> ---
> hw/s390x/s390-virtio-ccw.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 3dd0b2372d..2d75f2131f 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -438,10 +438,20 @@ static void s390_machine_reset(MachineState *machine,
> ShutdownCause reason)
> switch (reset_type) {
> case S390_RESET_EXTERNAL:
> case S390_RESET_REIPL:
> + /*
> + * Reset the subsystem which includes a AP reset. If a PV
> + * guest had APQNs attached the AP reset is a prerequisite to
> + * unprotecting since the UV checks if all APQNs are reset.
> + */
> + subsystem_reset();
> if (s390_is_pv()) {
> s390_machine_unprotect(ms);
> }
>
> + /*
> + * Device reset includes CPU clear resets so this has to be
> + * done AFTER the unprotect call above.
> + */
> qemu_devices_reset(reason);
> s390_crypto_reset();
>
I tested this with and without bound/associated APQNs both with booting
from disk and with direct kernel boot. Subsequent reboots are correctly
resetting the APQNs. I also successfully tested the case direct kernel
boot -> chreipl -> disk boot.
If you want you can add
Tested-by: Viktor Mihajlovski <mihaj...@linux.ibm.com>
