[Libguestfs] [PATCH] aarch64: launch: libvirt: As a workaround, pass -cpu parameter to qemu.

[Richard W.M. Jones]

From: "Richard W.M. Jones" <rjones at redhat.com>

When libguestfs is running using TCG on aarch64, we need to pass the
-cpu cortex-a57 parameter to qemu.  Libvirt doesn't let us do this,
complaining "Unable to find CPU definition".

As a temporary workaround only, use <qemu:commandline> to pass this
argument directly to qemu.  When libvirt is fixed we can remove this
hack.

This is a workaround for libvirt bug RHBZ#1184411.

See:
https://www.redhat.com/archives/libvirt-users/2014-August/msg00043.html
https://bugzilla.redhat.com/show_bug.cgi?id=1184411
---
 src/launch-libvirt.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
index 7a57f30..ca12320 100644
--- a/src/launch-libvirt.c
+++ b/src/launch-libvirt.c
@@ -1085,12 +1085,16 @@ construct_libvirt_xml_cpu (guestfs_h *g,
         } end_element ();
       }
       else {
-        /* XXX This does not work, see:
+        /* XXX This does not work on aarch64, see:
          * https://www.redhat.com/archives/libvirt-users/2014-August/msg00043.html
+	 * https://bugzilla.redhat.com/show_bug.cgi?id=1184411
+	 * Instead we hack around it using <qemu:commandline> below.
          */
+#ifndef __aarch64__
         start_element ("model") {
           string (cpu_model);
         } end_element ();
+#endif
       }
     } end_element ();
   }
@@ -1728,6 +1732,21 @@ construct_libvirt_xml_qemu_cmdline (guestfs_h *g,
       }
     }
 
+#ifdef __aarch64__
+    /* This is a temporary hack until RHBZ#1184411 is resolved.
+     * See comments above about cpu model and aarch64.
+     */
+    const char *cpu_model = guestfs___get_cpu_model (params->data->is_kvm);
+    if (STRNEQ (cpu_model, "host")) {
+      start_element ("qemu:arg") {
+        attribute ("value", "-cpu");
+      } end_element ();
+      start_element ("qemu:arg") {
+        attribute ("value", cpu_model);
+      } end_element ();
+    }
+#endif
+
   } end_element (); /* </qemu:commandline> */
 
   return 0;
-- 
1.8.3.1