hw/xen: Add "mode" parameter to xen-block devices

Block devices don't work in PV Grub (0.9x) if there is no mode specified. It
complains: "Error ENOENT when reading the mode"

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index 034a18b70e28da8be3026327e0d9f1f4064ee355..e61eab466c6aaa92669f73c69fc566c1d0cd1695 100644 (file)
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -408,6 +408,8 @@ static void xen_block_realize(XenDevice *xendev, Error **errp)
     }
 
     xen_device_backend_printf(xendev, "info", "%u", blockdev->info);
+    xen_device_backend_printf(xendev, "mode",
+                              (blockdev->info & VDISK_READONLY) ? "r" : "w");
 
     xen_device_frontend_printf(xendev, "virtual-device", "%lu",
                                vdev->number);