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.

v3 --> v4:
  * Restore correct object_dynamic_cast() in x86_iommu_realize()
  * Remove redundant casting in callee functions. Implemented in
    a new patch

Mohammed Gamal (3):
  x86_iommu: Move machine check to x86_iommu_realize()
  intel_iommu, amd_iommu: Remove redundant object_dynamic_cast calls
  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

On Mon, Sep 18, 2017 at 04:37:47PM +0200, Mohammed Gamal wrote:
> 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.
> 
> v3 --> v4:
>   * Restore correct object_dynamic_cast() in x86_iommu_realize()
>   * Remove redundant casting in callee functions. Implemented in
>     a new patch
> 
> Mohammed Gamal (3):
>   x86_iommu: Move machine check to x86_iommu_realize()
>   intel_iommu, amd_iommu: Remove redundant object_dynamic_cast calls
>   x86_iommu: check if machine has PCI bus

After patch 2 squashed to patch 1 (patch 2 itself is not valid; the
problem only appears after patch 1):

Reviewed-by: Peter Xu <peterx@redhat.com>

> 
>  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
> 

-- 
Peter Xu