[libvirt] [PATCH] qemuBuildDriveDevStr: Prefer default aliases for IDE bus

[Michal Privoznik]

https://bugzilla.redhat.com/show_bug.cgi?id=1434451

When testing user aliases it was discovered that for 440fx
machine type which has default IDE bus builtin, domain cannot
start if IDE controller has the user provided alias. This is
because for 440fx we don't put the IDE controller onto the
command line (since it is builtin) and therefore any device that
is plugged onto the bus must use the default alias.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/qemu/qemu_command.c                               | 14 +++++++++++---
 tests/qemuxml2argvdata/qemuxml2argv-user-aliases.args |  4 ++--
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 364196783..6cc77df2e 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1886,9 +1886,17 @@ qemuBuildDriveDevStr(const virDomainDef *def,
             virBufferAddLit(&opt, "ide-drive");
         }
 
-        if (!(contAlias = virDomainControllerAliasFind(def, VIR_DOMAIN_CONTROLLER_TYPE_IDE,
-                                                       disk->info.addr.drive.controller)))
-           goto error;
+        /* When domain has builtin IDE controller we don't put it onto cmd
+         * line. Therefore we can't set its alias. In that case, use the
+         * default one. */
+        if (qemuDomainHasBuiltinIDE(def)) {
+            contAlias = "ide";
+        } else {
+            if (!(contAlias = virDomainControllerAliasFind(def,
+                                                           VIR_DOMAIN_CONTROLLER_TYPE_IDE,
+                                                           disk->info.addr.drive.controller)))
+                goto error;
+        }
         virBufferAsprintf(&opt, ",bus=%s.%d,unit=%d",
                           contAlias,
                           disk->info.addr.drive.bus,
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-user-aliases.args b/tests/qemuxml2argvdata/qemuxml2argv-user-aliases.args
index 62fbd567b..1719c1bc8 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-user-aliases.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-user-aliases.args
@@ -44,8 +44,8 @@ id=drive-ua-myEncryptedDisk1 \
 id=ua-myEncryptedDisk1 \
 -drive file=/home/zippy/tmp/install-amd64-minimal-20140619.iso,format=raw,\
 if=none,media=cdrom,id=drive-ua-WhatAnAwesomeCDROM,readonly=on,cache=none \
--device ide-drive,bus=ua-DoesAnybodyStillUseIDE.1,unit=0,\
-drive=drive-ua-WhatAnAwesomeCDROM,id=ua-WhatAnAwesomeCDROM \
+-device ide-drive,bus=ide.1,unit=0,drive=drive-ua-WhatAnAwesomeCDROM,\
+id=ua-WhatAnAwesomeCDROM \
 -device virtio-net-pci,vlan=0,id=ua-CheckoutThisNIC,mac=52:54:00:d6:c0:0b,\
 bus=pci.0,addr=0x3 \
 -net tap,fd=3,vlan=0,name=hostua-CheckoutThisNIC \
-- 
2.13.6