From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:49108) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UD0xm-0005CN-Me for qemu-devel@nongnu.org; Tue, 05 Mar 2013 18:08:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UD0xl-00062W-Fh for qemu-devel@nongnu.org; Tue, 05 Mar 2013 18:08:02 -0500 Received: from mail-ob0-x233.google.com ([2607:f8b0:4003:c01::233]:34909) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UD0mo-0003F8-TY for qemu-devel@nongnu.org; Tue, 05 Mar 2013 17:56:42 -0500 Received: by mail-ob0-f179.google.com with SMTP id un3so3045275obb.24 for ; Tue, 05 Mar 2013 14:56:41 -0800 (PST) Message-ID: <51367864.6080502@ozlabs.ru> Date: Wed, 06 Mar 2013 09:57:40 +1100 From: Alexey Kardashevskiy MIME-Version: 1.0 References: <513596D7.3060307@ozlabs.ru> <20130305125614.GA2256@redhat.com> <5135F16B.2010403@ozlabs.ru> <20130305142336.GE2256@redhat.com> In-Reply-To: <20130305142336.GE2256@redhat.com> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] QEMU -netdev vhost=on + -device virtio-net-pci bug List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: rusty@rustcorp.com.au, "qemu-devel@nongnu.org" , David Gibson On 06/03/13 01:23, Michael S. Tsirkin wrote: > On Wed, Mar 06, 2013 at 12:21:47AM +1100, Alexey Kardashevskiy wrote: >> On 05/03/13 23:56, Michael S. Tsirkin wrote: >>>> The patch f56a12475ff1b8aa61210d08522c3c8aaf0e2648 "vhost: backend >>>> masking support" breaks virtio-net + vhost=on on PPC64 platform. >>>> >>>> The problem command line is: >>>> 1) -netdev tap,id=tapnet,ifname=tap0,script=qemu-ifup.sh,vhost=on \ >>>> -device virtio-net-pci,netdev=tapnet,addr=0.0 \ >>> >>> I think the issue is irqfd in not supported on kvm ppc. >> >> How can I make sure this is the case? Some work has been done there >> recently but midnight is quite late to figure this out :) > > Look in virtio_pci_set_guest_notifiers, what is the > value of with_irqfd? > bool with_irqfd = msix_enabled(&proxy->pci_dev) && > kvm_msi_via_irqfd_enabled(); > > Also check what each of the values in the expression above is. Yes, ppc does not have irqfd as kvm_msi_via_irqfd_enabled() returned "false". >>> Could you please check this: >>> >>> + /* If guest supports masking, set up irqfd now. >>> + * Otherwise, delay until unmasked in the frontend. >>> + */ >>> + if (proxy->vdev->guest_notifier_mask) { >>> + ret = kvm_virtio_pci_irqfd_use(proxy, queue_no, vector); >>> + if (ret < 0) { >>> + kvm_virtio_pci_vq_vector_release(proxy, vector); >>> + goto undo; >>> + } >>> + } >>> >>> >>> Could you please add a printf before "undo" and check whether the >>> error path above is triggered? >> >> >> Checked, it is not triggered. >> >> >> -- >> Alexey > > I think I get it. > Does the following help (probably not the right thing to do, but just > for testing): It did not compile (no "queue_no") :) I changed it a bit and now vhost=on works fine: diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c index a869f53..df1e443 100644 --- a/hw/virtio-pci.c +++ b/hw/virtio-pci.c @@ -798,6 +798,10 @@ static int virtio_pci_set_guest_notifiers(DeviceState *d, int nvqs, bool assign) if (r < 0) { goto assign_error; } + + if (!with_irqfd && proxy->vdev->guest_notifier_mask) { + proxy->vdev->guest_notifier_mask(proxy->vdev, n, !assign); + } } /* Must set vector notifier after guest notifier has been assigned */ > Signed-off-by: Michael S. Tsirkin > > --- > > diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c > index ba56ab2..c2a0c5a 100644 > --- a/hw/virtio-pci.c > +++ b/hw/virtio-pci.c > @@ -800,6 +800,10 @@ static int virtio_pci_set_guest_notifiers(DeviceState *d, int nvqs, bool assign) > } > } > > + if (!with_irqfd && proxy->vdev->guest_notifier_mask) { > + proxy->vdev->guest_notifier_mask(proxy->vdev, queue_no, !assign); > + } > + > /* Must set vector notifier after guest notifier has been assigned */ > if (with_irqfd && assign) { > proxy->vector_irqfd = > -- Alexey