Re: [Qemu-devel] [PATCH 2/3] s390: Virtual channel subsystem support.

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Mon, 12 Nov 2012 23:17:55 -0200
Marcelo Tosatti <mtosatti@redhat.com> wrote:

> Hi Cornelia,
> 
> On Wed, Oct 31, 2012 at 05:24:47PM +0100, Cornelia Huck wrote:
> > Provide a mechanism for qemu to provide fully virtual subchannels to
> > the guest. In the KVM case, this relies on the kernel's css support
> > for I/O and machine check interrupt handling. The !KVM case handles
> > interrupts on its own.
> > 
> > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> > ---
> >  hw/s390x/Makefile.objs     |    1 +
> >  hw/s390x/css.c             | 1209 ++++++++++++++++++++++++++++++++++++++++++++
> >  hw/s390x/css.h             |   90 ++++
> >  target-s390x/Makefile.objs |    2 +-
> >  target-s390x/cpu.h         |  232 +++++++++
> >  target-s390x/helper.c      |  146 ++++++
> >  target-s390x/ioinst.c      |  737 +++++++++++++++++++++++++++
> >  target-s390x/ioinst.h      |  213 ++++++++
> >  target-s390x/kvm.c         |  251 ++++++++-
> >  target-s390x/misc_helper.c |    6 +-
> >  10 files changed, 2872 insertions(+), 15 deletions(-)
> >  create mode 100644 hw/s390x/css.c
> >  create mode 100644 hw/s390x/css.h
> >  create mode 100644 target-s390x/ioinst.c
> >  create mode 100644 target-s390x/ioinst.h
> 
> > +void kvm_s390_enable_css_support(CPUS390XState *env)
> > +{
> > +    struct kvm_enable_cap cap = {};
> > +    int r;
> > +
> > +    /* Activate host kernel channel subsystem support. */
> > +    if (kvm_enabled()) {
> > +        /* One CPU has to run */
> > +        s390_add_running_cpu(env);
> 
> Care to explain this?

Old code leftovers; I've removed it.

> 
> > +
> > +        cap.cap = KVM_CAP_S390_CSS_SUPPORT;
> > +        r = kvm_vcpu_ioctl(env, KVM_ENABLE_CAP, &cap);
> > +        assert(r == 0);
> > +    }
> > +}
> 
>