xen: add a dummy xc_hvm_inject_msi for Xen < 4.2

xc_hvm_inject_msi is only available on Xen >= 4.2: add a dummy
compatibility function for Xen < 4.2.

Also enable msi support only on Xen >= 4.2.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/hw/xen.h b/hw/xen.h
index e5926b7b8a..3ae4cd0f5c 100644
--- a/hw/xen.h
+++ b/hw/xen.h
@@ -57,4 +57,14 @@ void xen_register_framebuffer(struct MemoryRegion *mr);
 #  define HVM_MAX_VCPUS 32
 #endif
 
+static inline int xen_msi_support(void)
+{
+#if defined(CONFIG_XEN_CTRL_INTERFACE_VERSION) \
+    && CONFIG_XEN_CTRL_INTERFACE_VERSION >= 420
+    return xen_enabled();
+#else
+    return 0;
+#endif
+}
+
 #endif /* QEMU_HW_XEN_H */