Re: [Qemu-devel] [PATCH for-1.2] msix: make [un]use vectors on reset/load optional

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

On Wed, Aug 29, 2012 at 06:44:49PM +0200, Jan Kiszka wrote:
> On 2012-08-29 18:40, Michael S. Tsirkin wrote:
> > The facility to use/unuse vectors dynamically is helpful
> > for virtio but little else: everyone just seems to use
> > vectors in their init function.
> > 
> > Avoid clearing msix vector use info on reset and load.
> > For virtio, clear it explicitly.
> > This should fix regressions reported with ivshmem - though
> > I didn't test this, I verified that virtio keeps
> > working like it did.
> > 
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> >  hw/msix.c       | 13 +++++++++++--
> >  hw/virtio-pci.c |  2 ++
> >  2 files changed, 13 insertions(+), 2 deletions(-)
> > 
> > diff --git a/hw/msix.c b/hw/msix.c
> > index 800fc32..d040cc2 100644
> > --- a/hw/msix.c
> > +++ b/hw/msix.c
> > @@ -340,6 +340,15 @@ static void msix_free_irq_entries(PCIDevice *dev)
> >      }
> >  }
> >  
> > +static void msix_clear_all_vectors(PCIDevice *dev)
> > +{
> > +    int vector;
> > +
> > +    for (vector = 0; vector < dev->msix_entries_nr; ++vector) {
> > +        msix_clr_pending(dev, vector);
> > +    }
> > +}
> > +
> >  /* Clean up resources for the device. */
> >  void msix_uninit(PCIDevice *dev, MemoryRegion *table_bar, MemoryRegion *pba_bar)
> >  {
> > @@ -394,7 +403,7 @@ void msix_load(PCIDevice *dev, QEMUFile *f)
> >          return;
> >      }
> >  
> > -    msix_free_irq_entries(dev);
> > +    msix_clear_all_vectors(dev);
> >      qemu_get_buffer(f, dev->msix_table, n * PCI_MSIX_ENTRY_SIZE);
> >      qemu_get_buffer(f, dev->msix_pba, (n + 7) / 8);
> >      msix_update_function_masked(dev);
> > @@ -440,7 +449,7 @@ void msix_reset(PCIDevice *dev)
> >      if (!msix_present(dev)) {
> >          return;
> >      }
> > -    msix_free_irq_entries(dev);
> > +    msix_clear_all_vectors(dev);
> >      dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &=
> >  	    ~dev->wmask[dev->msix_cap + MSIX_CONTROL_OFFSET];
> >      memset(dev->msix_table, 0, dev->msix_entries_nr * PCI_MSIX_ENTRY_SIZE);
> > diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> > index 125eded..ca0b204 100644
> > --- a/hw/virtio-pci.c
> > +++ b/hw/virtio-pci.c
> > @@ -131,6 +131,7 @@ static int virtio_pci_load_config(void * opaque, QEMUFile *f)
> >      if (ret) {
> >          return ret;
> >      }
> > +    msix_unuse_all_vectors(&proxy->pci_dev);
> >      msix_load(&proxy->pci_dev, f);
> >      if (msix_present(&proxy->pci_dev)) {
> >          qemu_get_be16s(f, &proxy->vdev->config_vector);
> > @@ -246,6 +247,7 @@ void virtio_pci_reset(DeviceState *d)
> >      VirtIOPCIProxy *proxy = container_of(d, VirtIOPCIProxy, pci_dev.qdev);
> >      virtio_pci_stop_ioeventfd(proxy);
> >      virtio_reset(proxy->vdev);
> > +    msix_unuse_all_vectors(&proxy->pci_dev);
> >      proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
> >  }
> >  
> > 
> 
> Fine with me, but let's ask Cam to test.
> 
> Jan

Cam deadline is today - can u test quickly pls?

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