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authorPaul Durrant <paul.durrant@citrix.com>2016-05-09 17:31:20 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2016-05-29 09:11:11 +0200
commita8ff4316795c7051b38727ec4a81c65dfcf63dc6 (patch)
tree356b2d842348e521e9d506dcac3872c02786d80c /xen-hvm.c
parenta4a0e4b258b2034559a546927794f477025d55d6 (diff)
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xen-hvm: ignore background I/O sections
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 <paul.durrant@citrix.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Anthony Perard <anthony.perard@citrix.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1462811480-16295-1-git-send-email-paul.durrant@citrix.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'xen-hvm.c')
-rw-r--r--xen-hvm.c14
1 files 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,