[PATCH v2 06/11] hw/pci-host/raven: Assert PCI I/O AddressSpace is based at 0x80000000

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

Commit 1ae1dc5ba24 ("raven: Set a correct PCI I/O memory region")
abused an AddressSpace API weakness which allows set non-zero base
address to AddressSpace root region. We will fix that in the next
commit. First add an assertion to ensure no regression is introduced.
As raven_io_address() is called by both MemoryRegionOps handlers, it
is a good place for such assert call.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/pci-host/raven.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/hw/pci-host/raven.c b/hw/pci-host/raven.c
index 730f31a8931..36652122424 100644
--- a/hw/pci-host/raven.c
+++ b/hw/pci-host/raven.c
@@ -141,6 +141,17 @@ static const MemoryRegionOps raven_intack_ops = {
 static inline hwaddr raven_io_address(PREPPCIState *s,
                                       hwaddr addr)
 {
+    /*
+     * We shouldn't access AddressSpace internals. However this assert
+     * is temporarily introduced to prove a subtle inconsistency from
+     * commit 1ae1dc5ba24 ("raven: Set a correct PCI I/O memory region"):
+     * AddressSpace root region must be zero-based, but the Raven use is not.
+     *
+     * Assert the root region is based on physical address 0x80000000
+     * until the issue is fixed.
+     */
+    assert(s->pci_io_as.root->addr == PCI_IO_BASE_ADDR);
+
     if (s->contiguous_map == 0) {
         /* 64 KB contiguous space for IOs */
         addr &= 0xFFFF;
-- 
2.26.3