Merge remote-tracking branch 'sstabellini/build_fix' into staging

* sstabellini/build_fix:
  xen: add a dummy xc_hvm_inject_msi for Xen < 4.2
  xen,configure: detect Xen 4.2

configure

@@ -1391,6 +1391,31 @@ EOF
 #if !defined(HVM_MAX_VCPUS)
 # error HVM_MAX_VCPUS not defined
 #endif
+int main(void) {
+  xc_interface *xc;
+  xs_daemon_open();
+  xc = xc_interface_open(0, 0, 0);
+  xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
+  xc_gnttab_open(NULL, 0);
+  xc_domain_add_to_physmap(0, 0, XENMAPSPACE_gmfn, 0, 0);
+  xc_hvm_inject_msi(xc, 0, 0xf0000000, 0x00000000);
+  return 0;
+}
+EOF
+      compile_prog "" "$xen_libs"
+    ) ; then
+    xen_ctrl_version=420
+    xen=yes
+
+  elif (
+      cat > $TMPC <<EOF
+#include <xenctrl.h>
+#include <xs.h>
+#include <stdint.h>
+#include <xen/hvm/hvm_info_table.h>
+#if !defined(HVM_MAX_VCPUS)
+# error HVM_MAX_VCPUS not defined
+#endif
 int main(void) {
   xc_interface *xc;
   xs_daemon_open();

hw/pc.c

@@ -916,7 +916,7 @@ static DeviceState *apic_init(void *env, uint8_t apic_id)
         msi_supported = true;
     }
 
-    if (xen_enabled()) {
+    if (xen_msi_support()) {
         msi_supported = true;
     }
 

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 */

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 */

xen-all.c

@@ -129,7 +129,7 @@ void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len)
 
 void xen_hvm_inject_msi(uint64_t addr, uint32_t data)
 {
-    xc_hvm_inject_msi(xen_xc, xen_domid, addr, data);
+    xen_xc_hvm_inject_msi(xen_xc, xen_domid, addr, data);
 }
 
 static void xen_suspend_notifier(Notifier *notifier, void *data)