From: David Woodhouse <dwmw@amazon.co.uk>

It isn't strictly mandatory but Linux guests at least will only map
their grant tables over the dummy BAR that it provides, and don't have
sufficient wit to map them in any other unused part of their guest
address space. So include it by default for minimal surprise factor.

As I come to document "how to run a Xen guest in QEMU", this means one
fewer thing to tell the user about, according to the mantra of "if it
needs documenting, fix it first, then document what remains".

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
---
 hw/i386/pc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index f4a08cc23f..fd17ce7a94 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1315,6 +1315,9 @@ void pc_basic_device_init(struct PCMachineState *pcms,
 #ifdef CONFIG_XEN_EMU
     if (xen_mode == XEN_EMULATE) {
         xen_evtchn_connect_gsis(gsi);
+        if (pcms->bus) {
+            pci_create_simple(pcms->bus, -1, "xen-platform");
+        }
     }
 #endif
 
-- 
2.39.0