File libxl.lock-qemu-machine-for-hvm.patch of Package xen

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File libxl.lock-qemu-machine-for-hvm.patch of Package xen (Revision 9ac012142019eedd61bbf2e417def7d6)

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From: Olaf Hering <olaf@aepfle.de>
Subject: libxl: lock qemu machine for hvm
References: bsc#1159755

libxl must not use 'xenfv' as qemu machine type because it maps just to
'pc', which means 'the latest variant of pc-i440fx'. Each new qemu
version will make slightly incompatible changes to this machine type,
which makes it impossible to migrate a domU from one qemu to another.
This happend to work until qemu-3, but broke with qemu-4:

With qemu.git commit 7fccf2a06890e3bc3b30e29827ad3fb93fe88fea a new
member smbus_no_migration_support was added, and enabled in two places.
With qemu.git commit 4ab2f2a8aabfea95cc53c64e13b3f67960b27fdf the
vmstate_acpi got new elements, which are conditionally filled. As a
result, an incoming migration expected smbus related data unless smbus
migration was disabled for a given MachineClass.

Since qemu commit 7fccf2a06890e3bc3b30e29827ad3fb93fe88fea forgot to
handle xenfv, live migration to receiving hosts using qemu-4.0 and later
is broken.

Start all new domUs with 'pc-i440fx-3.1' instead of 'xenfv'.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
 tools/libxl/libxl_dm.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -1751,23 +1751,20 @@ static int libxl__build_device_model_args_new(libxl__gc *gc,
     for (i = 0; b_info->extra && b_info->extra[i] != NULL; i++)
         flexarray_append(dm_args, b_info->extra[i]);
 
-    flexarray_append(dm_args, "-machine");
     switch (b_info->type) {
     case LIBXL_DOMAIN_TYPE_PVH:
     case LIBXL_DOMAIN_TYPE_PV:
+        flexarray_append(dm_args, "-machine");
         flexarray_append(dm_args, "xenpv");
         for (i = 0; b_info->extra_pv && b_info->extra_pv[i] != NULL; i++)
             flexarray_append(dm_args, b_info->extra_pv[i]);
         break;
     case LIBXL_DOMAIN_TYPE_HVM:
-        if (!libxl_defbool_val(b_info->u.hvm.xen_platform_pci)) {
-            /* Switching here to the machine "pc" which does not add
-             * the xen-platform device instead of the default "xenfv" machine.
-             */
-            machinearg = libxl__strdup(gc, "pc,accel=xen");
-        } else {
-            machinearg = libxl__strdup(gc, "xenfv");
+        if (libxl_defbool_val(b_info->u.hvm.xen_platform_pci)) {
+            flexarray_append(dm_args, "-device");
+            flexarray_append(dm_args, "xen-platform");
         }
+        machinearg = libxl__strdup(gc, "pc-i440fx-3.1,accel=xen");
         if (b_info->u.hvm.mmio_hole_memkb) {
             uint64_t max_ram_below_4g = (1ULL << 32) -
                 (b_info->u.hvm.mmio_hole_memkb << 10);
@@ -1798,6 +1795,7 @@ static int libxl__build_device_model_args_new(libxl__gc *gc,
             }
         }
 
+        flexarray_append(dm_args, "-machine");
         flexarray_append(dm_args, machinearg);
         for (i = 0; b_info->extra_hvm && b_info->extra_hvm[i] != NULL; i++)
             flexarray_append(dm_args, b_info->extra_hvm[i]);

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File libxl.lock-qemu-machine-for-hvm.patch of Package xen (Revision 9ac012142019eedd61bbf2e417def7d6)

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