From 5f5bfbd6da3c0994be68d163bc3d0bc5205d8609 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Sat, 27 Feb 2016 13:09:09 +0000
Subject: [PATCH] Fixes to allow (32 bit) arm guests to run on aarch64 hosts.

---
 mclu.pod     | 14 ++++++++++++++
 mclu_boot.ml | 28 +++++++++++++++++++++-------
 template.ml  |  6 ++++++
 template.mli |  1 +
 4 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/mclu.pod b/mclu.pod
index 54bc6f0..e82f14c 100644
--- a/mclu.pod
+++ b/mclu.pod
@@ -274,6 +274,12 @@ probe.
 
 The output format (eg. C<qcow2>).
 
+=item C<$guest_arch>
+
+The guest architecture (eg. "x86_64").  This is the output of the
+C<guest-arch> probe.  If the template doesn't provide that, it
+defaults to the cluster node's host architecture.
+
 =item C<$name>
 
 The hostname.
@@ -298,6 +304,14 @@ template can choose a default size.
 The template MAY print the disk type supported by this guest.  Possible
 values include C<ide>, C<virtio>, C<virtio-scsi>.
 
+=item guest-arch
+
+The template MAY print the guest architecture.
+
+If supplied, this acts as a hint when generating the XML in the C<mclu
+boot> subcommand.  The default is to assume the guest architecture is
+the same as the cluster host on which the guest runs.
+
 =item minimum-memory
 
 The template MAY print the minimum memory (RAM) required by this
diff --git a/mclu_boot.ml b/mclu_boot.ml
index 6da1bc5..c1054e5 100644
--- a/mclu_boot.ml
+++ b/mclu_boot.ml
@@ -170,9 +170,17 @@ Try: `mclu on %s'\n" hostname hostname;
   let remote_external_initrd = sprintf "/var/tmp/%s.boot/initrd" name in
   let remote_arch = node.MS.node_status.node_info.model in
 
+  (* Guest arch defaults to the node host arch, but can be overridden
+   * in the template.
+   *)
+  let guest_arch =
+    match template_info.Template.guest_arch with
+    | Some arch -> arch
+    | None -> remote_arch in
+
   (* UEFI firmware and NVRAM on remote, if required. *)
   let nvram =
-    match remote_arch with
+    match guest_arch with
     | "aarch64" ->
        Some ("/usr/share/edk2.git/aarch64/QEMU_EFI-pflash.raw",
              "/usr/share/edk2.git/aarch64/vars-template-pflash.raw",
@@ -204,9 +212,13 @@ Try: `mclu on %s'\n" hostname hostname;
     <boot dev='hd'/>
 " in
     let xml =
-      match remote_arch with
+      match guest_arch with
+      | "arm" | "armv7" | "armv7l" | "armv7hl" ->
+         xml ^ "\
+    <type arch='armv7l' machine='virt'>hvm</type>
+"
       | "aarch64" ->
-         xml ^ sprintf "\
+         xml ^ "\
     <type machine='virt'>hvm</type>
 "
       | _ ->
@@ -297,8 +309,10 @@ Try: `mclu on %s'\n" hostname hostname;
     </console>
 " in
     let xml =
-      if remote_arch = "x86_64" then (
-        xml ^ "\
+      match guest_arch with
+      | "i386" | "i486" | "i586" | "i686"
+      | "x86_64" ->
+         xml ^ "\
     <input type='tablet' bus='usb'/>
     <input type='mouse' bus='ps2'/>
     <input type='keyboard' bus='ps2'/>
@@ -307,8 +321,7 @@ Try: `mclu on %s'\n" hostname hostname;
       <model type='cirrus' vram='9216' heads='1'/>
     </video>
 "
-      ) else
-        xml in
+      | _ -> xml in
     let xml = xml ^ "\
   </devices>
 </domain>" in
@@ -387,6 +400,7 @@ Try: `mclu on %s'\n" hostname hostname;
     fpf "export LIBGUESTFS_BACKEND_SETTINGS=network_bridge=br0\n";
     fpf "export base_image=%s\n" (quote template_info.Template.base_image);
     fpf "export format=%s\n" (quote format);
+    fpf "export guest_arch=%s\n" (quote guest_arch);
     fpf "export name=%s\n" (quote name);
     fpf "export output=%s\n" (quote remote_image);
     (match size with
diff --git a/template.ml b/template.ml
index 4db0b66..20a5cc7 100644
--- a/template.ml
+++ b/template.ml
@@ -73,6 +73,7 @@ let run_template ~verbose filename subcmd args =
 
 type template_info = {
   base_image : string;
+  guest_arch : string option;
   minimum_memory : int64 option;
   recommended_memory : int64 option;
   minimum_size : int64 option;
@@ -98,6 +99,10 @@ let probe ?(verbose = false) filename =
     | _ ->
       eprintf "mclu: cannot parse '%s base-image'\n" filename;
       exit 1 in
+  let guest_arch =
+    match run_template ~verbose filename "guest-arch" [] with
+    | Some [arch] -> Some arch
+    | _ -> None in
   let minimum_memory =
     match run_template ~verbose filename "minimum-memory" [] with
     | Some [memory] ->
@@ -146,6 +151,7 @@ let probe ?(verbose = false) filename =
     | Some _ -> false in
 
   { base_image = base_image;
+    guest_arch = guest_arch;
     minimum_memory = minimum_memory;
     recommended_memory = recommended_memory;
     minimum_size = minimum_size;
diff --git a/template.mli b/template.mli
index bb1d7f2..2cec7b7 100644
--- a/template.mli
+++ b/template.mli
@@ -26,6 +26,7 @@ val template_names : unit -> string list
 
 type template_info = {
   base_image : string;
+  guest_arch : string option;
   minimum_memory : int64 option;
   recommended_memory : int64 option;
   minimum_size : int64 option;
-- 
1.8.3.1