The current libxl code doesn't deal with read-only drives at all. Upstream QEMU and qemu-xen only support read-only cdrom drives: make sure to specify "readonly=on" for cdrom drives and return error in case the user requested a non-cdrom read-only drive.
This is XSA-142, discovered by Lin Liu (https://bugzilla.redhat.com/show_bug.cgi?id=1257893). Signed-off-by: Stefano Stabellini <stefano.stabell...@eu.citrix.com> --- XSA-142 is still unissued at this time --- tools/libxl/libxl_dm.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c index 02c0162..468ff9c 100644 --- a/tools/libxl/libxl_dm.c +++ b/tools/libxl/libxl_dm.c @@ -1110,13 +1110,18 @@ static int libxl__build_device_model_args_new(libxl__gc *gc, if (disks[i].is_cdrom) { if (disks[i].format == LIBXL_DISK_FORMAT_EMPTY) drive = libxl__sprintf - (gc, "if=ide,index=%d,media=cdrom,cache=writeback,id=ide-%i", - disk, dev_number); + (gc, "if=ide,index=%d,readonly=%s,media=cdrom,cache=writeback,id=ide-%i", + disk, disks[i].readwrite ? "off" : "on", dev_number); else drive = libxl__sprintf - (gc, "file=%s,if=ide,index=%d,media=cdrom,format=%s,cache=writeback,id=ide-%i", - disks[i].pdev_path, disk, format, dev_number); + (gc, "file=%s,if=ide,index=%d,readonly=%s,media=cdrom,format=%s,cache=writeback,id=ide-%i", + disks[i].pdev_path, disk, disks[i].readwrite ? "off" : "on", format, dev_number); } else { + if (!disks[i].readwrite) { + LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "qemu-xen doesn't support read-only disk drivers"); + return ERROR_INVAL; + } + if (disks[i].format == LIBXL_DISK_FORMAT_EMPTY) { LIBXL__LOG(ctx, LIBXL__LOG_WARNING, "cannot support" " empty disk format for %s", disks[i].vdev); -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
