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authorCédric Le Goater <clg@redhat.com>2022-11-07 17:13:49 +0100
committerThomas Huth <thuth@redhat.com>2022-11-08 10:11:02 +0100
commitd3d1a406127f7da482eafbdc871c120c2770bb91 (patch)
tree10bebc9e5fc43fca7d39bddd2e03d1965d88e9ec /hw/s390x/s390-virtio-ccw.c
parent57702891376d4636b5eab4a89145152a0342c987 (diff)
s390x/s390-virtio-ccw: Switch off zPCI enhancements on older machines
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>
Diffstat (limited to 'hw/s390x/s390-virtio-ccw.c')
-rw-r--r--hw/s390x/s390-virtio-ccw.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index bb98d40792..7d80bc1837 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -844,9 +844,14 @@ static void ccw_machine_7_1_instance_options(MachineState *machine)
static void ccw_machine_7_1_class_options(MachineClass *mc)
{
S390CcwMachineClass *s390mc = S390_CCW_MACHINE_CLASS(mc);
+ static GlobalProperty compat[] = {
+ { TYPE_S390_PCI_DEVICE, "interpret", "off", },
+ { TYPE_S390_PCI_DEVICE, "forwarding-assist", "off", },
+ };
ccw_machine_7_2_class_options(mc);
compat_props_add(mc->compat_props, hw_compat_7_1, hw_compat_7_1_len);
+ compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
s390mc->max_threads = S390_MAX_CPUS;
}
DEFINE_CCW_MACHINE(7_1, "7.1", false);