Re: [Qemu-devel] [PATCH V2] hw/virtio: Add PCIe capability to virtio devices

[Marcel Apfelbaum]

On 10/28/2015 07:34 PM, Michael S. Tsirkin wrote:
> On Wed, Oct 28, 2015 at 07:16:06PM +0200, Marcel Apfelbaum wrote:
> > The virtio devices are converted to PCI-Express
> > if they are plugged into a PCI-Express bus and
> > the 'modern' protocol is enabled.
> >
> > Devices plugged directly into the Root Complex as
> > Integrated Endpoints remain PCI.
> >
> > Signed-off-by: Marcel Apfelbaum <address@hidden>
> > ---
> >
> > v1 -> v2:
> >   - Addressed Michael S. Tsirkin's comments:
> >     - Added the minimum required capabilities for PCIe devices
> >     - Integrated Endpoints remain PCI
> >
> >   - Use pcie_endpoint_cap_init instead of manually creating the pcie capability.
> >
> >   - Regarding Gerd Hoffman's comments:
> >     - Creating virtio-pcie devices:
> >       For the moment I prefer to not duplicate the virtio definitions,
> >       at least until we don't have a consensus (Personally I don't like it)
> >     - Removing the IO bar:
> >       This would be my next patch on the "virtio to express" series, I plan
> >       to remove it only for "modern" devices.
> >
> > Any comments would be appreciated,
> > Thanks,
> > Marcel
> >
> >   hw/virtio/virtio-pci.c | 19 +++++++++++++++++++
> >   1 file changed, 19 insertions(+)
>
> Looks good to me.  One minor point: need to make this conditional on 2.5
> machine type.

Hi Michael,

Makes sense to make this for 2.5+ machines.

Thanks for the review,
Marcel


> > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> > index f55dd2b..12d0ebb 100644
> > --- a/hw/virtio/virtio-pci.c
> > +++ b/hw/virtio/virtio-pci.c
> > @@ -1592,6 +1592,25 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error 
> > **errp)
> >
> >       address_space_init(&proxy->modern_as, &proxy->modern_cfg, 
> > "virtio-pci-cfg-as");
> >
> > +    if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN)
> > +        && pci_bus_is_express(pci_dev->bus)
> > +        && !pci_bus_is_root(pci_dev->bus)) {
> > +        int pos;
> > +
> > +        pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;
> > +        pos = pcie_endpoint_cap_init(pci_dev, 0);
> > +        assert(pos > 0);
> > +
> > +        pos = pci_add_capability(pci_dev, PCI_CAP_ID_PM, 0, PCI_PM_SIZEOF);
> > +        assert(pos > 0);
> > +
> > +        /*
> > +         * Indicates that this function complies with revision 1.2 of the
> > +         * PCI Power Management Interface Specification.
> > +         */
> > +        pci_set_word(pci_dev->config + pos + PCI_PM_PMC, 0x3);
> > +    }
> > +
> >       virtio_pci_bus_new(&proxy->bus, sizeof(proxy->bus), proxy);
> >       if (k->realize) {
> >           k->realize(proxy, errp);
> > --
> > 2.1.0