From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53356) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bQVRw-0003XC-3H for qemu-devel@nongnu.org; Fri, 22 Jul 2016 04:04:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bQVRr-0007Ip-2O for qemu-devel@nongnu.org; Fri, 22 Jul 2016 04:04:47 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39826) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bQVRq-0007Ie-OZ for qemu-devel@nongnu.org; Fri, 22 Jul 2016 04:04:42 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u6M83nnJ075192 for ; Fri, 22 Jul 2016 04:04:42 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 24assuu4tb-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 22 Jul 2016 04:04:41 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 22 Jul 2016 09:04:39 +0100 Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id A257017D805A for ; Fri, 22 Jul 2016 09:06:08 +0100 (BST) Received: from d06av06.portsmouth.uk.ibm.com (d06av06.portsmouth.uk.ibm.com [9.149.37.217]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u6M84bnN63242386 for ; Fri, 22 Jul 2016 08:04:37 GMT Received: from d06av06.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av06.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u6M84b4G007879 for ; Fri, 22 Jul 2016 04:04:37 -0400 Date: Fri, 22 Jul 2016 10:04:35 +0200 From: Cornelia Huck In-Reply-To: <146913602256.26732.547184422534259409.stgit@bahia.lan> References: <146913602256.26732.547184422534259409.stgit@bahia.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <20160722100435.1cf57293.cornelia.huck@de.ibm.com> Subject: Re: [Qemu-devel] [PATCH v4] 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: Greg Kurz Cc: "Michael S. Tsirkin" , Eric Blake , qemu-devel@nongnu.org, Marcel Apfelbaum On Thu, 21 Jul 2016 23:21:16 +0200 Greg Kurz wrote: > 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 > Signed-off-by: Greg Kurz > --- > 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 > --- > 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))) { I'm not sure that I didn't mess up the sequence of the realize callbacks, but could disable_legacy still be AUTO here? In that case, we'd fail for disable-modern=on and disable-legacy unset (i.e., AUTO), which would be ok for pcie but not for !pcie. > + 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; >