There are 3 highmem IO regions on arm/virt machine. Their base addresses
are determined dynamically. However, there are several issues I can see
in current implementation:

(1) The memory region's base address and highest_gpa are always updated
    no matter even if the memory region has been disabled. It's incorrectly
    incurring waste in the PA space.

(2) One particular memory region can be silently disabled due to the PA
    limit. We need warn users in this case. The warning messages are
    helpful to identify the cause of potential issues in future.

The issue (1) and (2) are fixed by PATCH[1] and PATCH[2] separately.

Gavin Shan (2):
  hw/arm/virt: Improve address assignment for highmem IO regions
  hw/arm/virt: Warn when high memory region is disabled

 hw/arm/virt.c | 72 +++++++++++++++++++++++++++++++++++----------------
 1 file changed, 49 insertions(+), 23 deletions(-)

-- 
2.23.0