xen: convert "-machine igd-passthru" to an accelerator property

The first machine property to fall is Xen's Intel integrated graphics
passthrough.  The "-machine igd-passthru" option does not set anymore
a property on the machine object, but desugars to a GlobalProperty on
accelerator objects.

The setter is very simple, since the value ends up in a
global variable, so this patch also provides an example before the more
complicated cases that follow it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 20 insertions, 0 deletions

diff --git a/hw/xen/xen-common.c b/hw/xen/xen-common.c
index 5284b0dec1..15650d7f6a 100644
--- a/hw/xen/xen-common.c
+++ b/hw/xen/xen-common.c
@@ -11,7 +11,9 @@
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
 #include "qemu/module.h"
+#include "qapi/error.h"
 #include "hw/xen/xen-legacy-backend.h"
+#include "hw/xen/xen_pt.h"
 #include "chardev/char.h"
 #include "sysemu/accel.h"
 #include "sysemu/runstate.h"
@@ -124,6 +126,16 @@ static void xen_change_state_handler(void *opaque, int running,
     }
 }
 
+static bool xen_get_igd_gfx_passthru(Object *obj, Error **errp)
+{
+    return has_igd_gfx_passthru;
+}
+
+static void xen_set_igd_gfx_passthru(Object *obj, bool value, Error **errp)
+{
+    has_igd_gfx_passthru = value;
+}
+
 static void xen_setup_post(MachineState *ms, AccelState *accel)
 {
     int rc;
@@ -177,6 +189,12 @@ static void xen_accel_class_init(ObjectClass *oc, void *data)
     ac->compat_props = g_ptr_array_new();
 
     compat_props_add(ac->compat_props, compat, G_N_ELEMENTS(compat));
+
+    object_class_property_add_bool(oc, "igd-passthru",
+        xen_get_igd_gfx_passthru, xen_set_igd_gfx_passthru,
+        &error_abort);
+    object_class_property_set_description(oc, "igd-passthru",
+        "Set on/off to enable/disable igd passthrou", &error_abort);
 }
 
 #define TYPE_XEN_ACCEL ACCEL_CLASS_NAME("xen")
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index 8fbaf2eae9..9e767d4244 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -65,6 +65,8 @@
 #include "qemu/range.h"
 #include "exec/address-spaces.h"
 
+bool has_igd_gfx_passthru;
+
 #define XEN_PT_NR_IRQS (256)
 static uint8_t xen_pt_mapped_machine_irq[XEN_PT_NR_IRQS] = {0};