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.

v1 --> v2:
* Change error message with capitalized acronym

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   | 10 +---------
 hw/i386/intel_iommu.c | 10 +---------
 hw/i386/x86-iommu.c   | 13 +++++++++++++
 3 files changed, 15 insertions(+), 18 deletions(-)

-- 
1.8.3.1

On Fri, Sep 15, 2017 at 05:04:35PM +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.
> 
> v1 --> v2:
> * Change error message with capitalized acronym
> 
> Mohammed Gamal (2):
>   x86_iommu: Move machine check to x86_iommu_realize()
>   x86_iommu: check if machine has PCI bus

I'm fine with even keeping object_dynamic_cast() there in patch 1, but
I agree with Eduardo's questioning.

For either case:

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

> 
>  hw/i386/amd_iommu.c   | 10 +---------
>  hw/i386/intel_iommu.c | 10 +---------
>  hw/i386/x86-iommu.c   | 13 +++++++++++++
>  3 files changed, 15 insertions(+), 18 deletions(-)
> 
> -- 
> 1.8.3.1
> 

-- 
Peter Xu