From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:37286) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ScPUG-0003zA-Kl for qemu-devel@nongnu.org; Wed, 06 Jun 2012 19:18:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ScPUE-00060O-PC for qemu-devel@nongnu.org; Wed, 06 Jun 2012 19:18:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:4502) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ScPUE-00060G-H1 for qemu-devel@nongnu.org; Wed, 06 Jun 2012 19:17:58 -0400 Message-ID: <1339024663.23475.338.camel@bling.home> From: Alex Williamson Date: Wed, 06 Jun 2012 17:17:43 -0600 In-Reply-To: <4FBF3627.3030504@ozlabs.ru> References: <4FBF3627.3030504@ozlabs.ru> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Subject: Re: [Qemu-devel] [RFC PATCH] vfio: add fixup for broken PCI devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: qemu-devel@nongnu.org, Alex Graf , kvm@vger.kernel.org, David Gibson 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. > > 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 | Sorry, just taking a look at this again. Do you have any idea what fixup it is that makes it work? Calling a fixup at this point seems rather odd. I suspect the problem is that vfio is only calling pci_load_and_free_saved_state if pci_reset_function reports that it worked. kvm device assignment doesn't do that and I'm not sure why I did that. If you unconditionally call pci_load_and_free_saved_state a bit further down in this function, does it solve the problem? Thanks, Alex