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, 15 insertions, 0 deletions

diff --git a/hw/xen_common.h b/hw/xen_common.h
index 0409ac7971..7043c14cae 100644
--- a/hw/xen_common.h
+++ b/hw/xen_common.h
@@ -133,6 +133,21 @@ static inline int xc_fd(xc_interface *xen_xc)
 }
 #endif
 
+/* Xen before 4.2 */
+#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 420
+static inline int xen_xc_hvm_inject_msi(XenXC xen_xc, domid_t dom,
+        uint64_t addr, uint32_t data)
+{
+    return -ENOSYS;
+}
+#else
+static inline int xen_xc_hvm_inject_msi(XenXC xen_xc, domid_t dom,
+        uint64_t addr, uint32_t data)
+{
+    return xc_hvm_inject_msi(xen_xc, dom, addr, data);
+}
+#endif
+
 void destroy_hvm_domain(void);
 
 #endif /* QEMU_HW_XEN_COMMON_H */