From: Paul Durrant <[email protected]> Since Xen will correctly handle accesses to unimplemented I/O ports (by returning all 1's for reads and ignoring writes) there is no need for QEMU to register backgroud I/O sections.
This patch therefore adds checks to xen_io_add/del so that sections with memory-region ops pointing at 'unassigned_io_ops' are ignored. Signed-off-by: Paul Durrant <[email protected]> Cc: Stefano Stabellini <[email protected]> Cc: Anthony Perard <[email protected]> Cc: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Acked-by: Anthony PERARD <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> --- xen-hvm.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/xen-hvm.c b/xen-hvm.c index c14e778..01ee25d 100644 --- a/xen-hvm.c +++ b/xen-hvm.c @@ -511,8 +511,13 @@ static void xen_io_add(MemoryListener *listener, MemoryRegionSection *section) { XenIOState *state = container_of(listener, XenIOState, io_listener); + MemoryRegion *mr = section->mr; - memory_region_ref(section->mr); + if (mr->ops == &unassigned_io_ops) { + return; + } + + memory_region_ref(mr); xen_map_io_section(xen_xc, xen_domid, state->ioservid, section); } @@ -521,10 +526,15 @@ static void xen_io_del(MemoryListener *listener, MemoryRegionSection *section) { XenIOState *state = container_of(listener, XenIOState, io_listener); + MemoryRegion *mr = section->mr; + + if (mr->ops == &unassigned_io_ops) { + return; + } xen_unmap_io_section(xen_xc, xen_domid, state->ioservid, section); - memory_region_unref(section->mr); + memory_region_unref(mr); } static void xen_device_realize(DeviceListener *listener, -- 2.5.5
