[Qemu-devel] [PATCH 26/32] vfio-pci: Fix multifunction=on

[Michael Roth <mdroth@linux.vnet.ibm.com>]

From: Alex Williamson <alex.williamson@redhat.com>

When an assigned device is initialized it copies the device config
space into the emulated config space.  Unfortunately multifunction is
setup prior to the device initfn and gets clobbered.  We need to
restore it just like pci-assign does.

Cc: qemu-stable@nongnu.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 8d07d6c46597a885eb38d99cc6fff399ce69cd21)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/misc/vfio.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index 017e693..d9e78e1 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -3142,6 +3142,13 @@ static int vfio_initfn(PCIDevice *pdev)
     vdev->emulated_config_bits[PCI_HEADER_TYPE] =
                                               PCI_HEADER_TYPE_MULTI_FUNCTION;
 
+    /* Restore or clear multifunction, this is always controlled by QEMU */
+    if (vdev->pdev.cap_present & QEMU_PCI_CAP_MULTIFUNCTION) {
+        vdev->pdev.config[PCI_HEADER_TYPE] |= PCI_HEADER_TYPE_MULTI_FUNCTION;
+    } else {
+        vdev->pdev.config[PCI_HEADER_TYPE] &= ~PCI_HEADER_TYPE_MULTI_FUNCTION;
+    }
+
     /*
      * Clear host resource mapping info.  If we choose not to register a
      * BAR, such as might be the case with the option ROM, we can get
-- 
1.7.9.5