Starting qemu with
qemu-system-x86_64 -S -M isapc -device {amd|intel}-iommu
leads to a segfault. The code assume PCI bus is present and
tries to access the bus structure without checking.

The patch series moves the error checks from vtd_realize()
and amdvi_realize() to the generic x86_iommu_realize() and
adds a check for PCI bus presence.

v4 --> v5:
   * Squash patch 2/3 from v4 into patch 1/3

Mohammed Gamal (2):
  x86_iommu: Move machine check to x86_iommu_realize()
  x86_iommu: check if machine has PCI bus

 hw/i386/amd_iommu.c   | 13 ++-----------
 hw/i386/intel_iommu.c | 13 ++-----------
 hw/i386/x86-iommu.c   | 13 +++++++++++++
 3 files changed, 17 insertions(+), 22 deletions(-)

-- 
1.8.3.1