xen: make it possible to build without the Xen PV domain builder

Until the previous patch this relied on xc_fd(), which was only
implemented for Xen 4.0 and earlier.

Given this wasn't working since Xen 4.0 I have marked this as disabled
by default.

Removing this support drops the use of a bunch of symbols from
libxenctrl, specifically:

  - xc_domain_create
  - xc_domain_destroy
  - xc_domain_getinfo
  - xc_domain_max_vcpus
  - xc_domain_setmaxmem
  - xc_domain_unpause
  - xc_evtchn_alloc_unbound
  - xc_linux_build

This is another step towards only using Xen libraries which provide a
stable inteface.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

configure

@@ -250,6 +250,7 @@ vnc_jpeg=""
 vnc_png=""
 xen=""
 xen_ctrl_version=""
+xen_pv_domain_build="no"
 xen_pci_passthrough=""
 linux_aio=""
 cap_ng=""
@@ -927,6 +928,10 @@ for opt do
   ;;
   --enable-xen-pci-passthrough) xen_pci_passthrough="yes"
   ;;
+  --disable-xen-pv-domain-build) xen_pv_domain_build="no"
+  ;;
+  --enable-xen-pv-domain-build) xen_pv_domain_build="yes"
+  ;;
   --disable-brlapi) brlapi="no"
   ;;
   --enable-brlapi) brlapi="yes"
@@ -2229,6 +2234,12 @@ if test "$xen_pci_passthrough" != "no"; then
   fi
 fi
 
+if test "$xen_pv_domain_build" = "yes" &&
+   test "$xen" != "yes"; then
+    error_exit "User requested Xen PV domain builder support" \
+	       "which requires Xen support."
+fi
+
 ##########################################
 # libtool probe
 
@@ -4848,6 +4859,7 @@ fi
 echo "xen support       $xen"
 if test "$xen" = "yes" ; then
   echo "xen ctrl version  $xen_ctrl_version"
+  echo "pv dom build      $xen_pv_domain_build"
 fi
 echo "brlapi support    $brlapi"
 echo "bluez  support    $bluez"
@@ -5219,6 +5231,9 @@ fi
 if test "$xen" = "yes" ; then
   echo "CONFIG_XEN_BACKEND=y" >> $config_host_mak
   echo "CONFIG_XEN_CTRL_INTERFACE_VERSION=$xen_ctrl_version" >> $config_host_mak
+  if test "$xen_pv_domain_build" = "yes" ; then
+    echo "CONFIG_XEN_PV_DOMAIN_BUILD=y" >> $config_host_mak
+  fi
 fi
 if test "$linux_aio" = "yes" ; then
   echo "CONFIG_LINUX_AIO=y" >> $config_host_mak

hw/xenpv/Makefile.objs

@@ -1,2 +1,4 @@
 # Xen PV machine support
-obj-$(CONFIG_XEN) += xen_domainbuild.o xen_machine_pv.o
+obj-$(CONFIG_XEN) += xen_machine_pv.o
+# Xen PV machine builder support
+obj-$(CONFIG_XEN_PV_DOMAIN_BUILD) += xen_domainbuild.o

hw/xenpv/xen_machine_pv.c

@@ -30,9 +30,6 @@
 
 static void xen_init_pv(MachineState *machine)
 {
-    const char *kernel_filename = machine->kernel_filename;
-    const char *kernel_cmdline = machine->kernel_cmdline;
-    const char *initrd_filename = machine->initrd_filename;
     DriveInfo *dinfo;
     int i;
 
@@ -46,17 +43,27 @@ static void xen_init_pv(MachineState *machine)
     case XEN_ATTACH:
         /* nothing to do, xend handles everything */
         break;
-    case XEN_CREATE:
+#ifdef CONFIG_XEN_PV_DOMAIN_BUILD
+    case XEN_CREATE: {
+        const char *kernel_filename = machine->kernel_filename;
+        const char *kernel_cmdline = machine->kernel_cmdline;
+        const char *initrd_filename = machine->initrd_filename;
         if (xen_domain_build_pv(kernel_filename, initrd_filename,
                                 kernel_cmdline) < 0) {
             fprintf(stderr, "xen pv domain creation failed\n");
             exit(1);
         }
         break;
+    }
+#endif
     case XEN_EMULATE:
         fprintf(stderr, "xen emulation not implemented (yet)\n");
         exit(1);
         break;
+    default:
+        fprintf(stderr, "unhandled xen_mode %d\n", xen_mode);
+        exit(1);
+        break;
     }
 
     xen_be_register("console", &xen_console_ops);

include/hw/xen/xen_common.h

@@ -505,6 +505,7 @@ static inline int xen_xc_domain_add_to_physmap(XenXC xch, uint32_t domid,
 }
 #endif
 
+#ifdef CONFIG_XEN_PV_DOMAIN_BUILD
 #if CONFIG_XEN_CTRL_INTERFACE_VERSION < 470
 static inline int xen_domain_create(XenXC xc, uint32_t ssidref,
                                     xen_domain_handle_t handle, uint32_t flags,
@@ -520,6 +521,7 @@ static inline int xen_domain_create(XenXC xc, uint32_t ssidref,
     return xc_domain_create(xc, ssidref, handle, flags, pdomid, NULL);
 }
 #endif
+#endif
 
 #if CONFIG_XEN_CTRL_INTERFACE_VERSION < 471