Re: [PATCH v3 06/17] s390x: protvirt: Add migration blocker

[Cornelia Huck <cohuck@redhat.com>]

On Fri, 14 Feb 2020 10:16:25 -0500
Janosch Frank <frankja@linux.ibm.com> wrote:

> Migration is not yet supported.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  hw/s390x/s390-virtio-ccw.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 5fa4372083..d64724af91 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -42,6 +42,9 @@
>  #include "hw/s390x/tod.h"
>  #include "sysemu/sysemu.h"
>  #include "hw/s390x/pv.h"
> +#include "migration/blocker.h"
> +
> +static Error *pv_mig_blocker;
>  
>  S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
>  {
> @@ -373,6 +376,7 @@ static void s390_machine_reset(MachineState *machine)
>      CPUState *cs, *t;
>      S390CPU *cpu;
>      S390CcwMachineState *ms = S390_CCW_MACHINE(machine);
> +    static Error *local_err;
>  
>      /* get the reset parameters, reset them once done */
>      s390_ipl_get_reset_request(&cs, &reset_type);
> @@ -422,6 +426,17 @@ static void s390_machine_reset(MachineState *machine)
>          }
>          run_on_cpu(cs, s390_do_cpu_reset, RUN_ON_CPU_NULL);
>  
> +        if (!pv_mig_blocker) {
> +            error_setg(&pv_mig_blocker,
> +                       "protected VMs are currently not migrateable.");
> +        }
> +        migrate_add_blocker(pv_mig_blocker, &local_err);

If I'm not lost in the context, that's during PV_RESET. I'm a bit
confused why you'd add the blocker here?

> +        if (local_err) {
> +            error_report_err(local_err);
> +            error_free(pv_mig_blocker);
> +            exit(1);

Why the exit()? Can't you fail the call?

> +        }
> +
>          if (s390_machine_pv_secure(ms)) {
>              CPU_FOREACH(t) {
>                  s390_pv_vcpu_destroy(t);
> @@ -430,6 +445,7 @@ static void s390_machine_reset(MachineState *machine)
>              ms->pv = false;
>  
>              s390_machine_inject_pv_error(cs);
> +            migrate_del_blocker(pv_mig_blocker);
>              s390_cpu_set_state(S390_CPU_STATE_OPERATING, cpu);
>              return;
>          }