Blame SOURCES/kvm-s390x-s390-virtio-ccw-Switch-off-zPCI-enhancements-o.patch

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From c7b14d3af7c73a3bf0c00911b85f202840d9b414 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@redhat.com>
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Date: Mon, 7 Nov 2022 17:13:49 +0100
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Subject: [PATCH 12/42] s390x/s390-virtio-ccw: Switch off zPCI enhancements on
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 older machines
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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RH-Author: Cédric Le Goater <clg@redhat.com>
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RH-MergeRequest: 226: s390: Enhanced Interpretation for PCI Functions and Secure Execution guest dump
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RH-Bugzilla: 1664378 2043909
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RH-Acked-by: Thomas Huth <thuth@redhat.com>
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RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
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RH-Acked-by: Jon Maloy <jmaloy@redhat.com>
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RH-Commit: [12/41] 61e32bab6d68ee9abd6a0751944af82e002b05b4
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zPCI enhancement features (interpretation and forward assist) were
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recently introduced to improve performance on PCI passthrough devices.
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To maintain the same behaviour on older Z machines, deactivate the
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features with the associated properties.
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Signed-off-by: Cédric Le Goater <clg@redhat.com>
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Message-Id: <20221107161349.1032730-3-clg@kaod.org>
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Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
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Signed-off-by: Thomas Huth <thuth@redhat.com>
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(cherry picked from commit d3d1a406127f7da482eafbdc871c120c2770bb91)
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[ clg: applied zPCI restrictions to rhel8.5.0 machine and below ]
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Signed-off-by: Cédric Le Goater <clg@redhat.com>
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---
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 hw/s390x/s390-virtio-ccw.c | 6 ++++++
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 1 file changed, 6 insertions(+)
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diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
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index bec270598b..bd80e72cf8 100644
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--- a/hw/s390x/s390-virtio-ccw.c
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+++ b/hw/s390x/s390-virtio-ccw.c
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@@ -1130,8 +1130,14 @@ static void ccw_machine_rhel850_instance_options(MachineState *machine)
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 static void ccw_machine_rhel850_class_options(MachineClass *mc)
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 {
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+    static GlobalProperty compat[] = {
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+        { TYPE_S390_PCI_DEVICE, "interpret", "off", },
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+        { TYPE_S390_PCI_DEVICE, "forwarding-assist", "off", },
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+    };
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+
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     ccw_machine_rhel860_class_options(mc);
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     compat_props_add(mc->compat_props, hw_compat_rhel_8_5, hw_compat_rhel_8_5_len);
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+    compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
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     mc->smp_props.prefer_sockets = true;
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 }
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 DEFINE_CCW_MACHINE(rhel850, "rhel8.5.0", false);
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-- 
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2.37.3
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