Re: [Qemu-devel] [qemu-s390x] [PULL 06/15] s390x/tod: factor out TOD into separate device

[Cornelia Huck]

On Thu, 11 Oct 2018 14:15:41 +0200
Thomas Huth <address@hidden> wrote:

> On 2018-07-02 13:17, Cornelia Huck wrote:
> > From: David Hildenbrand <address@hidden>
> > 
> > Let's treat this like a separate device. TCG will have to store the
> > actual state/time later on.
> > 
> > Include cpu-qom.h in kvm_s390x.h (due to S390CPU) to compile tod-kvm.c.  
> 
> This patch breaks "make check" when QEMU has been compiled with
> --disable-tcg on s390x:
> 
> $ gdb --args s390x-softmmu/qemu-system-s390x -nographic -accel qtest
> [...]
> ERROR:qom/object.c:549:object_new_with_type: assertion failed: (type != NULL)
> 
> Program received signal SIGABRT, Aborted.
> [...]
> (gdb) bt
> #0  0x000003fffcac1220 in raise () from /lib64/libc.so.6
> #1  0x000003fffcac2aa8 in abort () from /lib64/libc.so.6
> #2  0x000003fffd0fdd5e in g_assertion_message () from /lib64/libglib-2.0.so.0
> #3  0x000003fffd0fddc6 in g_assertion_message_expr () from 
> /lib64/libglib-2.0.so.0
> #4  0x00000001002d4bf2 in object_new_with_type (type=0x0)
>     qom/object.c:549
> #5  0x00000001002d4d6e in object_new (address@hidden "s390-tod-qemu")
>     at qom/object.c:563
> #6  0x00000001001c04ee in s390_init_tod () at hw/s390x/tod.c:25
> #7  0x0000000100233d00 in machine_run_board_init (machine=0x1008f5510)
>     at hw/core/machine.c:834
> #8  0x000000010012cb08 in main (argc=<optimized out>, argv=<optimized out>, 
> envp=<optimized out>)
>     at vl.c:4489
> 
> > diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
> > index dc704b57d6..93282f7c59 100644
> > --- a/hw/s390x/Makefile.objs
> > +++ b/hw/s390x/Makefile.objs
> > @@ -14,6 +14,9 @@ obj-$(CONFIG_PCI) += s390-pci-bus.o s390-pci-inst.o
> >  obj-$(call lnot,$(CONFIG_PCI)) += s390-pci-stub.o
> >  obj-y += s390-skeys.o
> >  obj-y += s390-stattrib.o
> > +obj-y += tod.o
> > +obj-$(CONFIG_KVM) += tod-kvm.o
> > +obj-$(CONFIG_TCG) += tod-qemu.o  
> 
> With --disable-tcg, tod-qemu.o is not included in the build.
> 
> [...]
> > diff --git a/hw/s390x/tod.c b/hw/s390x/tod.c
> > new file mode 100644
> > index 0000000000..0501affa7f
> > --- /dev/null
> > +++ b/hw/s390x/tod.c
> > @@ -0,0 +1,119 @@
> > +/*
> > + * TOD (Time Of Day) clock
> > + *
> > + * Copyright 2018 Red Hat, Inc.
> > + * Author(s): David Hildenbrand <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or 
> > later.
> > + * See the COPYING file in the top-level directory.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "hw/s390x/tod.h"
> > +#include "qapi/error.h"
> > +#include "qemu/error-report.h"
> > +#include "sysemu/kvm.h"
> > +#include "migration/register.h"
> > +
> > +void s390_init_tod(void)
> > +{
> > +    Object *obj;
> > +
> > +    if (kvm_enabled()) {
> > +        obj = object_new(TYPE_KVM_S390_TOD);
> > +    } else {
> > +        obj = object_new(TYPE_QEMU_S390_TOD);
> > +    }  
> 
> ... but with "-accel qtest", QEMU tries to instantiate the object here.
> 
> I think we should maybe simply inclue tod-qemu.o unconditionally? Opinions?

If tod-qemu does not depend on tcg stuff, that sounds like the easiest
solution.