From c7b14d3af7c73a3bf0c00911b85f202840d9b414 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@redhat.com>
Date: Mon, 7 Nov 2022 17:13:49 +0100
Subject: [PATCH 12/42] s390x/s390-virtio-ccw: Switch off zPCI enhancements on
 older machines
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RH-Author: Cédric Le Goater <clg@redhat.com>
RH-MergeRequest: 226: s390: Enhanced Interpretation for PCI Functions and Secure Execution guest dump
RH-Bugzilla: 1664378 2043909
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
RH-Acked-by: Jon Maloy <jmaloy@redhat.com>
RH-Commit: [12/41] 61e32bab6d68ee9abd6a0751944af82e002b05b4

zPCI enhancement features (interpretation and forward assist) were
recently introduced to improve performance on PCI passthrough devices.
To maintain the same behaviour on older Z machines, deactivate the
features with the associated properties.

Signed-off-by: Cédric Le Goater <clg@redhat.com>
Message-Id: <20221107161349.1032730-3-clg@kaod.org>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit d3d1a406127f7da482eafbdc871c120c2770bb91)
[ clg: applied zPCI restrictions to rhel8.5.0 machine and below ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 hw/s390x/s390-virtio-ccw.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index bec270598b..bd80e72cf8 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -1130,8 +1130,14 @@ static void ccw_machine_rhel850_instance_options(MachineState *machine)
 
 static void ccw_machine_rhel850_class_options(MachineClass *mc)
 {
+    static GlobalProperty compat[] = {
+        { TYPE_S390_PCI_DEVICE, "interpret", "off", },
+        { TYPE_S390_PCI_DEVICE, "forwarding-assist", "off", },
+    };
+
     ccw_machine_rhel860_class_options(mc);
     compat_props_add(mc->compat_props, hw_compat_rhel_8_5, hw_compat_rhel_8_5_len);
+    compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
     mc->smp_props.prefer_sockets = true;
 }
 DEFINE_CCW_MACHINE(rhel850, "rhel8.5.0", false);
-- 
2.37.3