[Qemu-devel] [PATCH 0/2] PPC: kvm: Fix incorrect remapping of in-kernel MPIC

[Bogdan Purcareata]

On target-ppc, the kvm-openpic memory region is part of the E500-CCSR memory
region. On the kernel side, the MPIC is mapped at the same offset as the
kvm-openpic within the address space.

When adding the PCI BAR0 memory region, an alias is created to point to the
E500-CCSR memory region. This results in firing the kvm_openpic_region_add once
more, since kvm-openpic is part of the latter. Only this time, the offset is
wrong - it's part of the PCI memory region. This leads to the in-kernel MPIC to
be remapped at a wrong address, and thus all traps to the kvm-openpic
address to be emulated in userspace.

The fix consists in an additional filter in kvm_openpic_region_{add,del} to
consider only addresses matching the start of the kvm-openpic memory region.