From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [RFC PATCH] vfio: add fixup for broken PCI devices Date: Fri, 25 May 2012 18:28:38 +1000 Message-ID: <1337934518.16119.15.camel@pasglop> References: <4FBF3627.3030504@ozlabs.ru> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, Alex Williamson , Alex Graf , kvm@vger.kernel.org, David Gibson To: Alexey Kardashevskiy Return-path: In-Reply-To: <4FBF3627.3030504@ozlabs.ru> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org On Fri, 2012-05-25 at 17:35 +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. I think we should create a new quirk category... call it pci_fixup_reset or something like that, which is responsible for blasting the thing into submission when ownership changes. We'll need these for more than just USB I suspect. Cheers, Ben. > Signed-off-by: Alexey Kardashevskiy > --- > 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 |