Conflicting virtual addresses causing Runtime Services issues

["Jon Nettleton" <jon@solid-run.com>]

I am debugging a failure that I am seeing while using the HoneyComb's
spi-nor flash for runtime variable storage.  I am hoping someone on
the list can give me some insight as what may be the problem.

The problem showed up when we switched the MMIO region for the fspi
flash device to be marked as non executable.  reading variables is
fine, however writes began throwing an error.

[  556.709828] Unable to handle kernel execute from non-executable
memory at virtual address 00000000206a3968

I have patched the kernel and removed the X86 requirement and enabled
the sysfs runtime mappings kernel config so I can get an easy view of
the mappings the kernel carries for runtime services.  I then track
that virtual address to the MMIO region of nor flash, which makes
sense that region is marked as non executable.  The question is why is
code being executed from this address range

attribute
::::::::::::::
0x8000000000000001
::::::::::::::
num_pages
::::::::::::::
0x40
::::::::::::::
phys_addr
::::::::::::::
0x20500000
::::::::::::::
type
::::::::::::::
0xb
::::::::::::::
virt_addr
::::::::::::::
0x20680000

So then I patched the PL011 serial driver to be able to log to the
console in runtime and I track down the access to Status =
Fvb->GetPhysicalAddress(Fvb, &FvVolHdr); in UpdateVariableStore().
What I don't understand is why EfiConvertPointer is mapping that
pointer into the Virtual address space occupied by the runtime mmio of
the flash.  The pointer is being properly remapped.  Here are the
pointer addresses in EFI and Kernel Runtime

EFI:
UpdateVariableStore:156 ECE33968
FvbGetPhysicalAddress(BaseAddress=0x20000000)

KERNEL:
UpdateVariableStore:156 206A3968
[  556.709828] Unable to handle kernel execute from non-executable
memory at virtual address 00000000206a3968

Any insight that anyone could provide would be much appreciated.

Thanks,
Jon