From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [Qemu-devel] [RFC PATCH] vfio: add fixup for broken PCI devices Date: Mon, 28 May 2012 15:44:12 +0300 Message-ID: <20120528124410.GC21778@redhat.com> References: <4FBF3627.3030504@ozlabs.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alex Williamson , kvm@vger.kernel.org, qemu-devel@nongnu.org, Alex Graf , David Gibson To: Alexey Kardashevskiy Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37233 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751859Ab2E1MoS (ORCPT ); Mon, 28 May 2012 08:44:18 -0400 Content-Disposition: inline In-Reply-To: <4FBF3627.3030504@ozlabs.ru> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, May 25, 2012 at 05:35:03PM +1000, Alexey Kardashevskiy wrote: > Some adapters (like NEC PCI USB controller) do not flush their config > on a sioftware reset and remember DMA config, etc. > > If we use such an adapter with QEMU, then crash QEMU (stop it with > ctrl-A ctrl-X), and try to use it in QEMU again, it may start working > immediately with previous config when pci_enable_device() is called > on that PCI function. > > To eliminate such effect, some quirk should be called. The proposed > pci_fixup_final does its job well for mentioned NEC PCI USB but not > sure if it is 100% correct. > > Signed-off-by: Alexey Kardashevskiy Won't current kvm device assignment be affected by this? If yes need to address that not just vfio. > --- > drivers/vfio/pci/vfio_pci.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index 1e5315c..6e7c12d 100644 > --- a/drivers/vfio/pci/vfio_pci.c > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -88,6 +88,8 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev) > { > int bar; > > + pci_fixup_device(pci_fixup_final, vdev->pdev); > + > pci_disable_device(vdev->pdev); > > vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE | > -- > 1.7.7.3