Re: [Qemu-devel] [PATCH for v1.0 1/3] msix: track function masked in pci device state

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Dec 04, 2011 at 01:35:03PM +0100, Jan Kiszka wrote:
> On 2011-12-04 11:20, Michael S. Tsirkin wrote:
> > On Fri, Dec 02, 2011 at 04:34:21PM -0700, Cam Macdonell wrote:
> >> Based on a git bisect, this patch breaks msi-x interrupt delivery in
> >> the ivshmem device.
> > 
> > I think the following should fix it. Compiled-only -
> > could you pls check? If yes let's apply to the stable branch.
> > 
> > -->
> > 
> > ivshmem: add missing msix calls
> > 
> > ivshmem used msix but didn't call it on either reset or
> > config write paths. This used to partically work since
> > guests don't use all of msi-x configuration fields,
> > and reset is rarely used, but the patch 'msix: track function masked
> > in pci device state' broke that. Fix by adding appropriate calls.
> > 
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > 
> > --
> > 
> > diff --git a/hw/ivshmem.c b/hw/ivshmem.c
> > index 242fbea..3680c0f 100644
> > --- a/hw/ivshmem.c
> > +++ b/hw/ivshmem.c
> > @@ -505,6 +505,7 @@ static void ivshmem_reset(DeviceState *d)
> >      IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
> >  
> >      s->intrstatus = 0;
> > +    msix_reset(&s->dev);
> >      return;
> >  }
> >  
> > @@ -610,6 +611,13 @@ static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
> >      return 0;
> >  }
> >  
> > +static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
> > +				 uint32_t val, int len)
> > +{
> > +    pci_default_write_config(pci_dev, address, val, len);
> > +    msix_write_config(pci_dev, address, val, len);
> > +}
> > +
> >  static int pci_ivshmem_init(PCIDevice *dev)
> >  {
> >      IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
> > @@ -734,6 +742,8 @@ static int pci_ivshmem_init(PCIDevice *dev)
> >  
> >      }
> >  
> > +    s->dev.config_write = ivshmem_write_config;
> > +
> >      return 0;
> >  }
> >  
> > 
> > 
> 
> But please fix this for real and merge [1]&[2] (with depending patches)
> into master. The above is just boilerplate code from device POV.
> 
> Jan
> 
> [1] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/80240
> [2] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/80244
> 

Yes, I agree we should make it easier for devices.
What annoyed me was the need to put msix in save/load.

And that is because of the need to do this in a specific
order.  I hope to switch to an unordered format and
then this will become straight-forward.

-- 
MST