Re: [Qemu-devel] [Qemu-stable] [PATCH 06/25] pci: Use bus master address space for delivering MSI/MSI-X messages

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Quoting Greg Kurz (2014-08-28 05:18:06)
> On Wed, 27 Aug 2014 12:36:03 -0500
> Michael Roth <mdroth@linux.vnet.ibm.com> wrote:
> > From: Jan Kiszka <jan.kiszka@siemens.com>
> > 
> > The spec says (and real HW confirms this) that, if the bus master bit
> > is 0, the device will not generate any PCI accesses. MSI and MSI-X
> > messages fall among these, so we should use the corresponding address
> > space to deliver them. This will prevent delivery if bus master support
> > is disabled.
> > 
> > Cc: qemu-stable@nongnu.org
> > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > (cherry picked from commit cc943c36faa192cd4b32af8fe5edb31894017d35)
> > Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> > ---
> 
> Hi Michael,
> 
> This commit breaks virtio for spapr. A fix is available in Alex's ppc-next:
> 
> From: Greg Kurz <gkurz@linux.vnet.ibm.com>
> spapr_pci: map the MSI window in each PHB 
> 
> https://github.com/agraf/qemu/commit/7af2868fc76857e19c232bbe9e99a95d61138213

Thanks, I've gone ahead and applied it. Tested virtio + pseries before/after
and it seems to fix the issue.

> 
> Cheers.
> 
> --
> Greg
> 
> >  hw/pci/msi.c  | 2 +-
> >  hw/pci/msix.c | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/hw/pci/msi.c b/hw/pci/msi.c
> > index a4a3040..52d2313 100644
> > --- a/hw/pci/msi.c
> > +++ b/hw/pci/msi.c
> > @@ -291,7 +291,7 @@ void msi_notify(PCIDevice *dev, unsigned int vector)
> >                     "notify vector 0x%x"
> >                     " address: 0x%"PRIx64" data: 0x%"PRIx32"\n",
> >                     vector, msg.address, msg.data);
> > -    stl_le_phys(&address_space_memory, msg.address, msg.data);
> > +    stl_le_phys(&dev->bus_master_as, msg.address, msg.data);
> >  }
> > 
> >  /* Normally called by pci_default_write_config(). */
> > diff --git a/hw/pci/msix.c b/hw/pci/msix.c
> > index 5c49bfc..20ae476 100644
> > --- a/hw/pci/msix.c
> > +++ b/hw/pci/msix.c
> > @@ -439,7 +439,7 @@ void msix_notify(PCIDevice *dev, unsigned vector)
> > 
> >      msg = msix_get_message(dev, vector);
> > 
> > -    stl_le_phys(&address_space_memory, msg.address, msg.data);
> > +    stl_le_phys(&dev->bus_master_as, msg.address, msg.data);
> >  }
> > 
> >  void msix_reset(PCIDevice *dev)
> 
> 
> 
> -- 
> Gregory Kurz                                     kurzgreg@fr.ibm.com
>                                                  gkurz@linux.vnet.ibm.com
> Software Engineer @ IBM/Meiosys                  http://www.ibm.com
> Tel +33 (0)562 165 496
> 
> "Anarchy is about taking complete responsibility for yourself."
>         Alan Moore.