Commit a8ff4316 authored by Paul Durrant's avatar Paul Durrant Committed by Paolo Bonzini
Browse files

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: default avatarPaul 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: default avatarAnthony PERARD <anthony.perard@citrix.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent a4a0e4b2

xen-hvm.c

+12 −2
Original line number Diff line number Diff line
@@ -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,