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authorIgor Mammedov <imammedo@redhat.com>2014-02-06 11:24:33 +0100
committerMichael S. Tsirkin <mst@redhat.com>2014-03-09 21:09:37 +0200
commit8e46bbf362458fc3e4638a53249248a1ee40b912 (patch)
treeea67711e41b7b1496f47063776aef92efa2af53b /memory.c
parentddfa83ea06680e83643978f6ecf740b60f86f7c2 (diff)
memory_region_present: return false if address is not found in child MemoryRegion
Windows XP shows COM2 port as non functional in "Device Manager" although no COM2 port backing device is present in QEMU. This regression is really due to 3bb28b7208b349e7a1b326e3c6ef9efac1d462bf? memory: Provide separate handling of unassigned io ports accesses That is caused by the fact that QEMU reports to OSPM that device is present by setting 5th bit in PII4XPM.pci_conf[0x67] register when COM2 doesn't exist. It happens due to memory_region_present(io_as, 0x2f8) returning false positive since 0x2f8 address eventually translates into catchall io_as address space. Fix memory_region_present(parent, addr) by returning true only if addr maps into a MemoryRegion within parent (excluding parent itself), to match its doc comment. While at it fix copy/paste error in memory_region_present() doc comment. Note: this is a temporary hack: we really need better handling for unassigned regions, we should avoid fallback regions since they are bad for performance (breaking radix tree assumption that the data structure is sparsely populated); for memory we need to fix this to implement PCI master abort properly, anyway. Cc: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'memory.c')
-rw-r--r--memory.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/memory.c b/memory.c
index 59ecc28401..3f1df238e2 100644
--- a/memory.c
+++ b/memory.c
@@ -1562,7 +1562,7 @@ static FlatRange *flatview_lookup(FlatView *view, AddrRange addr)
bool memory_region_present(MemoryRegion *parent, hwaddr addr)
{
MemoryRegion *mr = memory_region_find(parent, addr, 1).mr;
- if (!mr) {
+ if (!mr || (mr == parent)) {
return false;
}
memory_region_unref(mr);