diff options
Diffstat (limited to 'hw/xen')
| -rw-r--r-- | hw/xen/xen-bus.c | 47 |
1 files changed, 31 insertions, 16 deletions
diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c index 55c157393d..c2ad22a42d 100644 --- a/hw/xen/xen-bus.c +++ b/hw/xen/xen-bus.c @@ -857,6 +857,13 @@ static void xen_device_frontend_changed(void *opaque) } } +static bool xen_device_frontend_exists(XenDevice *xendev) +{ + enum xenbus_state state; + + return (xen_device_frontend_scanf(xendev, "state", "%u", &state) == 1); +} + static void xen_device_frontend_create(XenDevice *xendev, Error **errp) { XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); @@ -865,19 +872,25 @@ static void xen_device_frontend_create(XenDevice *xendev, Error **errp) xendev->frontend_path = xen_device_get_frontend_path(xendev); - perms[0].id = xendev->frontend_id; - perms[0].perms = XS_PERM_NONE; - perms[1].id = xenbus->backend_id; - perms[1].perms = XS_PERM_READ | XS_PERM_WRITE; + /* + * The frontend area may have already been created by a legacy + * toolstack. + */ + if (!xen_device_frontend_exists(xendev)) { + perms[0].id = xendev->frontend_id; + perms[0].perms = XS_PERM_NONE; + perms[1].id = xenbus->backend_id; + perms[1].perms = XS_PERM_READ | XS_PERM_WRITE; - g_assert(xenbus->xsh); + g_assert(xenbus->xsh); - xs_node_create(xenbus->xsh, XBT_NULL, xendev->frontend_path, perms, - ARRAY_SIZE(perms), &local_err); - if (local_err) { - error_propagate_prepend(errp, local_err, - "failed to create frontend: "); - return; + xs_node_create(xenbus->xsh, XBT_NULL, xendev->frontend_path, perms, + ARRAY_SIZE(perms), &local_err); + if (local_err) { + error_propagate_prepend(errp, local_err, + "failed to create frontend: "); + return; + } } xendev->frontend_state_watch = @@ -1290,12 +1303,14 @@ static void xen_device_realize(DeviceState *dev, Error **errp) xen_device_backend_set_online(xendev, true); xen_device_backend_set_state(xendev, XenbusStateInitWait); - xen_device_frontend_printf(xendev, "backend", "%s", - xendev->backend_path); - xen_device_frontend_printf(xendev, "backend-id", "%u", - xenbus->backend_id); + if (!xen_device_frontend_exists(xendev)) { + xen_device_frontend_printf(xendev, "backend", "%s", + xendev->backend_path); + xen_device_frontend_printf(xendev, "backend-id", "%u", + xenbus->backend_id); - xen_device_frontend_set_state(xendev, XenbusStateInitialising, true); + xen_device_frontend_set_state(xendev, XenbusStateInitialising, true); + } xendev->exit.notify = xen_device_exit; qemu_add_exit_notifier(&xendev->exit); |