Re: [Qemu-devel] [PATCH v1 0/5][RFC] Refactoring of AIS support

[Pierre Morel]

On 30/10/2017 18:08, Christian Borntraeger wrote:
> On 10/30/2017 05:59 PM, Cornelia Huck wrote:
> > On Mon, 30 Oct 2017 14:48:23 +0100
> > Christian Borntraeger <address@hidden> wrote:
> >
> >
> > > FWIW, I am testing a guest patch that enables zPCI without AIS. Its as simple as
> > >
> > >
> > > diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
> > > index 7b30af5..9b24836 100644
> > > --- a/arch/s390/pci/pci.c
> > > +++ b/arch/s390/pci/pci.c
> > > @@ -953,7 +953,7 @@ static int __init pci_base_init(void)
> > >          if (!s390_pci_probe)
> > >                  return 0;
> > >   
> > > -       if (!test_facility(69) || !test_facility(71) || !test_facility(72))
> > > +       if (!test_facility(69) || !test_facility(71))
> > >                  return 0;
> > >   
> > >          rc = zpci_debug_init();
> > > diff --git a/arch/s390/pci/pci_insn.c b/arch/s390/pci/pci_insn.c
> > > index ea34086..61f8c82 100644
> > > --- a/arch/s390/pci/pci_insn.c
> > > +++ b/arch/s390/pci/pci_insn.c
> > > @@ -7,6 +7,7 @@
> > >   #include <linux/export.h>
> > >   #include <linux/errno.h>
> > >   #include <linux/delay.h>
> > > +#include <asm/facility.h>
> > >   #include <asm/pci_insn.h>
> > >   #include <asm/pci_debug.h>
> > >   #include <asm/processor.h>
> > > @@ -93,6 +94,8 @@ int zpci_refresh_trans(u64 fn, u64 addr, u64 range)
> > >   /* Set Interruption Controls */
> > >   void zpci_set_irq_ctrl(u16 ctl, char *unused, u8 isc)
> > >   {
> > > +       if (!test_facility(72))
> > > +               return;
> > >          asm volatile (
> > >                  "       .insn   rsy,0xeb00000000d1,%[ctl],%[isc],%[u]\n"
> > >                  : : [ctl] "d" (ctl), [isc] "d" (isc << 27), [u] "Q" (*unused));
> >
> > Sounds good. Presumably this makes the adapter interrupt handling work
> > as for virtio (and qdio)? Is there any ais-less pci hardware out in the
> > wild?
>
> ais is z specific, not PCI specific. So PCI cards should not care as far as I 
> can tell.

I bet Conny meant PCI hardware globaly, including zPCI adapters.
I bet none but I will better ask Sebastian or Gerald if they know.


--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany