[libvirt] [PATCH] qemu: raise an error when trying to use readonly ide disks

[Giuseppe Scrivano]

The IDE bus doesn't support readonly disks, so inform the user with an
error message instead of let qemu fail with a more obscure "Device
'ide-hd' could not be initialized" error message.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1112939

Signed-off-by: Giuseppe Scrivano <gscrivan at redhat.com>
---
 src/qemu/qemu_command.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 63f322a..4829176 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -3385,8 +3385,15 @@ qemuBuildDriveStr(virConnectPtr conn,
         disk->bus != VIR_DOMAIN_DISK_BUS_IDE)
         virBufferAddLit(&opt, ",boot=on");
     if (disk->readonly &&
-        virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_READONLY))
+        virQEMUCapsGet(qemuCaps, QEMU_CAPS_DRIVE_READONLY)) {
+        if (disk->bus == VIR_DOMAIN_DISK_BUS_IDE &&
+            disk->device == VIR_DOMAIN_DISK_DEVICE_DISK) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("readonly ide disks are not supported"));
+            goto error;
+        }
         virBufferAddLit(&opt, ",readonly=on");
+    }
     if (disk->transient) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                        _("transient disks not supported yet"));
-- 
1.9.3