kvm/i386: Add xen-evtchn-max-pirq property

The default number of PIRQs is set to 256 to avoid issues with 32-bit MSI
devices. Allow it to be increased if the user desires.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index d390137f02..1aef54f87e 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -5922,6 +5922,33 @@ static void kvm_arch_set_xen_gnttab_max_frames(Object *obj, Visitor *v,
     s->xen_gnttab_max_frames = value;
 }
 
+static void kvm_arch_get_xen_evtchn_max_pirq(Object *obj, Visitor *v,
+                                             const char *name, void *opaque,
+                                             Error **errp)
+{
+    KVMState *s = KVM_STATE(obj);
+    uint16_t value = s->xen_evtchn_max_pirq;
+
+    visit_type_uint16(v, name, &value, errp);
+}
+
+static void kvm_arch_set_xen_evtchn_max_pirq(Object *obj, Visitor *v,
+                                             const char *name, void *opaque,
+                                             Error **errp)
+{
+    KVMState *s = KVM_STATE(obj);
+    Error *error = NULL;
+    uint16_t value;
+
+    visit_type_uint16(v, name, &value, &error);
+    if (error) {
+        error_propagate(errp, error);
+        return;
+    }
+
+    s->xen_evtchn_max_pirq = value;
+}
+
 void kvm_arch_accel_class_init(ObjectClass *oc)
 {
     object_class_property_add_enum(oc, "notify-vmexit", "NotifyVMexitOption",
@@ -5954,6 +5981,13 @@ void kvm_arch_accel_class_init(ObjectClass *oc)
                               NULL, NULL);
     object_class_property_set_description(oc, "xen-gnttab-max-frames",
                                           "Maximum number of grant table frames");
+
+    object_class_property_add(oc, "xen-evtchn-max-pirq", "uint16",
+                              kvm_arch_get_xen_evtchn_max_pirq,
+                              kvm_arch_set_xen_evtchn_max_pirq,
+                              NULL, NULL);
+    object_class_property_set_description(oc, "xen-evtchn-max-pirq",
+                                          "Maximum number of Xen PIRQs");
 }
 
 void kvm_set_max_apic_id(uint32_t max_apic_id)