Re: [Qemu-devel] [PATCH v4] virtio-pci: error out when both legacy and modern modes are disabled

[Marcel Apfelbaum]

On 07/22/2016 12:55 AM, Greg Kurz wrote:
> On Thu, 21 Jul 2016 23:21:16 +0200
> Greg Kurz <address@hidden> wrote:
>
> > From: Greg Kurz <address@hidden>
> >
> > Without presuming if we got there because of a user mistake or some
> > more subtle bug in the tooling, it really does not make sense to
> > implement a non-functional device.
> >
> > Signed-off-by: Greg Kurz <address@hidden>
> > Reviewed-by: Marcel Apfelbaum <address@hidden>
> > Signed-off-by: Greg Kurz <address@hidden>
> > ---
> > v4: - rephrased error message and provide a hint to the user
> >      - split string literals to stay below 80 characters
> >      - added Marcel's R-b tag
> > ---
>
> Marcel,
>
> I see that Michael has comments on your patch. If you feel this patch is 
> valuable
> for 2.7, please consider carrying and pushing it, as I'm about to take a 1-month
> leave.

I'll be sure to take it form here, thanks for the help!
Marcel

> Thanks.
>
> --
> Greg
>
> >   hw/virtio/virtio-pci.c |    8 ++++++++
> >   1 file changed, 8 insertions(+)
> >
> > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> > index 755f9218b77d..72c4b392ffda 100644
> > --- a/hw/virtio/virtio-pci.c
> > +++ b/hw/virtio/virtio-pci.c
> > @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, 
> > Error **errp)
> >       VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev);
> >       PCIDevice *pci_dev = &proxy->pci_dev;
> >
> > +    if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) {
> > +        error_setg(errp, "device cannot work when both modern and legacy modes"
> > +                   " are disabled");
> > +        error_append_hint(errp, "Set either disable-modern or disable-legacy"
> > +                          " to off\n");
> > +        return;
> > +    }
> > +
> >       if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) &&
> >           virtio_pci_modern(proxy)) {
> >           pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;