[Qemu-devel] [RFC PATCH] vfio: add fixup for broken PCI devices

[Alexey Kardashevskiy <aik@ozlabs.ru>]

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 <aik@ozlabs.ru>
---
 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