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Date: Wed, 27 Jan 2016 11:46:12 +0800
From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Thomas Monjalon <thomas.monjalon@6wind.com>
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Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v5 8/9] virtio: add 1.0 support
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On Thu, Jan 21, 2016 at 12:49:10PM +0100, Thomas Monjalon wrote:
> 2016-01-19 16:12, Yuanhan Liu:
> >  int
> >  vtpci_init(struct rte_pci_device *dev, struct virtio_hw *hw)
> >  {
> > -       hw->vtpci_ops = &legacy_ops;
> > +       hw->dev = dev;
> > +
> > +       /*
> > +        * Try if we can succeed reading virtio pci caps, which exists
> > +        * only on modern pci device. If failed, we fallback to legacy
> > +        * virtio handling.
> > +        */
> > +       if (virtio_read_caps(dev, hw) == 0) {
> > +               PMD_INIT_LOG(INFO, "modern virtio pci detected.");
> > +               hw->vtpci_ops = &modern_ops;
> > +               hw->modern    = 1;
> > +               dev->driver->drv_flags |= RTE_PCI_DRV_INTR_LSC;
> > +               return 0;
> > +       }
> 
> RTE_PCI_DRV_INTR_LSC is already set by virtio_resource_init_by_uio().

We don't go that far here. Here we just detect if it's a modern virtio
device. And if yes, we do some modern initiations, and return.

virtio_resource_init_by_uio() is invoked when virtio_read_caps() fails.

> Do you mean interrupt was not supported with legacy virtio?

Nope. this patch set changes nothing on legacy virtio support.

	--yliu