From f73d7cff45504deb36b502d073157576528a6eb3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Fri, 15 Jan 2021 15:49:05 +0000
Subject: [PATCH] Guest: fix to always use host-passthrough CPU for all arches
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The use of host passthrough was restricted to just arm architectures,
which meant other arches got their built in default, which is almost
never what you want. eg x86 gets qemu64 which lacks so many features
that some guests will not function at all.

There is no need to care about live migration with Oz, so it should
unconditionally use host-passthrough for all architectures when KVM
is enabled.

Furthermore the way host-passthrough was requested was incorrect
and relying on an accident of the libvirt QEMU impl. It needs to
use mode=host-passthrough, not mode=custom + model=host. Libvirt
should block the latter from being used.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 oz/Guest.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/oz/Guest.py b/oz/Guest.py
index 92bdc71c..aac57bd8 100644
--- a/oz/Guest.py
+++ b/oz/Guest.py
@@ -470,10 +470,10 @@
             oz.ozutil.lxml_subelement(features, "apic")
             oz.ozutil.lxml_subelement(features, "pae")
         # CPU
-        if self.tdl.arch in ["aarch64", "armv7l"] and self.libvirt_type == "kvm":
-            # Possibly related to RHBZ 1171501 - need host passthrough for aarch64 and arm with kvm
-            cpu = oz.ozutil.lxml_subelement(domain, "cpu", None, {'mode': 'host-passthrough', 'check': 'none'})
-            oz.ozutil.lxml_subelement(cpu, "model", "host", {'fallback': 'allow'})
+        if self.libvirt_type == "kvm":
+            # If using KVM, we always want the best CPU the host can offer
+            # as we don't need to worry about live migration portability
+            oz.ozutil.lxml_subelement(domain, "cpu", None, {'mode': 'host-passthrough'})
         # os
         osNode = oz.ozutil.lxml_subelement(domain, "os")
         mods = None