From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58871) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhw0O-0004Qp-AC for qemu-devel@nongnu.org; Thu, 08 Sep 2016 05:52:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bhw0L-0000M7-2i for qemu-devel@nongnu.org; Thu, 08 Sep 2016 05:52:24 -0400 Received: from 1.mo68.mail-out.ovh.net ([46.105.41.146]:49096) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhw0K-0000Lz-SK for qemu-devel@nongnu.org; Thu, 08 Sep 2016 05:52:20 -0400 Received: from player778.ha.ovh.net (b7.ovh.net [213.186.33.57]) by mo68.mail-out.ovh.net (Postfix) with ESMTP id E3CB0FF9827 for ; Thu, 8 Sep 2016 11:52:19 +0200 (CEST) Date: Thu, 8 Sep 2016 11:52:15 +0200 From: Greg Kurz Message-ID: <20160908115215.2ec9e3e3@bahia> In-Reply-To: <87a8fiyi9b.fsf@dusky.pond.sub.org> References: <147326875705.8546.11347276277137015855.stgit@bahia.lan> <147326877255.8546.8636563472418354481.stgit@bahia.lan> <87a8fiyi9b.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/2] virtio-pci: error out when both legacy and modern modes are disabled List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: "Michael S. Tsirkin" , qemu-devel@nongnu.org, "Aneesh Kumar K.V" On Thu, 08 Sep 2016 09:15:28 +0200 Markus Armbruster wrote: > Greg Kurz writes: > > > From: Greg Kurz > > > > 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 > > Reviewed-by: Marcel Apfelbaum > > Reviewed-by: Cornelia Huck > > Signed-off-by: Greg Kurz > > --- > > 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 268fd8ebb219..4b6a8a356621 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 as neither modern nor legacy mode" > > + " is enabled"); > > + 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; > > Pardon my ignorance... is this a device-specific restriction, or is it > the same for more (all?) virtio devices? Yes this for all virtio devices. But wait, I now realize that the check isn't done in the right place because if we don't pass an explicit disable-legacy=on then proxy->disable_legacy gets its final value in virtio_pci_realize() which gets called after virtio_pci_dc_realize()... I'll fix that. Thanks ! -- Greg