xen: Support new libxc calls from xen unstable.

This patch updates the libxenctrl calls in Qemu to use the new interface,
otherwise Qemu wouldn't be able to build against new versions of the
library.

We check libxenctrl version in configure, from Xen 3.3.0 to Xen
unstable.

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

configure

@@ -127,6 +127,7 @@ vnc_jpeg=""
 vnc_png=""
 vnc_thread="no"
 xen=""
+xen_ctrl_version=""
 linux_aio=""
 attr=""
 vhost_net=""
@@ -1180,20 +1181,81 @@ fi
 
 if test "$xen" != "no" ; then
   xen_libs="-lxenstore -lxenctrl -lxenguest"
+
+  # Xen unstable
   cat > $TMPC <<EOF
 #include <xenctrl.h>
 #include <xs.h>
-int main(void) { xs_daemon_open(); xc_interface_open(); return 0; }
+#include <stdint.h>
+#include <xen/hvm/hvm_info_table.h>
+#if !defined(HVM_MAX_VCPUS)
+# error HVM_MAX_VCPUS not defined
+#endif
+int main(void) {
+  xc_interface *xc;
+  xs_daemon_open();
+  xc = xc_interface_open(0, 0, 0);
+  xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
+  xc_gnttab_open(NULL, 0);
+  return 0;
+}
 EOF
   if compile_prog "" "$xen_libs" ; then
+    xen_ctrl_version=410
     xen=yes
-    libs_softmmu="$xen_libs $libs_softmmu"
+
+  # Xen 4.0.0
+  elif (
+      cat > $TMPC <<EOF
+#include <xenctrl.h>
+#include <xs.h>
+#include <stdint.h>
+#include <xen/hvm/hvm_info_table.h>
+#if !defined(HVM_MAX_VCPUS)
+# error HVM_MAX_VCPUS not defined
+#endif
+int main(void) {
+  xs_daemon_open();
+  xc_interface_open();
+  xc_gnttab_open();
+  xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
+  return 0;
+}
+EOF
+      compile_prog "" "$xen_libs"
+    ) ; then
+    xen_ctrl_version=400
+    xen=yes
+
+  # Xen 3.3.0, 3.4.0
+  elif (
+      cat > $TMPC <<EOF
+#include <xenctrl.h>
+#include <xs.h>
+int main(void) {
+  xs_daemon_open();
+  xc_interface_open();
+  xc_gnttab_open();
+  xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
+  return 0;
+}
+EOF
+      compile_prog "" "$xen_libs"
+    ) ; then
+    xen_ctrl_version=330
+    xen=yes
+
+  # Xen not found or unsupported
   else
     if test "$xen" = "yes" ; then
       feature_not_found "xen"
     fi
     xen=no
   fi
+
+  if test "$xen" = yes; then
+    libs_softmmu="$xen_libs $libs_softmmu"
+  fi
 fi
 
 ##########################################
@@ -2855,6 +2917,7 @@ if test "$bluez" = "yes" ; then
 fi
 if test "$xen" = "yes" ; then
   echo "CONFIG_XEN=y" >> $config_host_mak
+  echo "CONFIG_XEN_CTRL_INTERFACE_VERSION=$xen_ctrl_version" >> $config_host_mak
 fi
 if test "$io_thread" = "yes" ; then
   echo "CONFIG_IOTHREAD=y" >> $config_host_mak

hw/xen_backend.c

@@ -43,7 +43,8 @@
 /* ------------------------------------------------------------- */
 
 /* public */
-int xen_xc;
+XenXC xen_xc = XC_HANDLER_INITIAL_VALUE;
+XenGnttab xen_xcg = XC_HANDLER_INITIAL_VALUE;
 struct xs_handle *xenstore = NULL;
 const char *xen_protocol;
 
@@ -214,8 +215,8 @@ static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
     xendev->debug      = debug;
     xendev->local_port = -1;
 
-    xendev->evtchndev = xc_evtchn_open();
-    if (xendev->evtchndev < 0) {
+    xendev->evtchndev = xen_xc_evtchn_open(NULL, 0);
+    if (xendev->evtchndev == XC_HANDLER_INITIAL_VALUE) {
         xen_be_printf(NULL, 0, "can't open evtchn device\n");
         qemu_free(xendev);
         return NULL;
@@ -223,15 +224,15 @@ static struct XenDevice *xen_be_get_xendev(const char *type, int dom, int dev,
     fcntl(xc_evtchn_fd(xendev->evtchndev), F_SETFD, FD_CLOEXEC);
 
     if (ops->flags & DEVOPS_FLAG_NEED_GNTDEV) {
-        xendev->gnttabdev = xc_gnttab_open();
-        if (xendev->gnttabdev < 0) {
+        xendev->gnttabdev = xen_xc_gnttab_open(NULL, 0);
+        if (xendev->gnttabdev == XC_HANDLER_INITIAL_VALUE) {
             xen_be_printf(NULL, 0, "can't open gnttab device\n");
             xc_evtchn_close(xendev->evtchndev);
             qemu_free(xendev);
             return NULL;
         }
     } else {
-        xendev->gnttabdev = -1;
+        xendev->gnttabdev = XC_HANDLER_INITIAL_VALUE;
     }
 
     QTAILQ_INSERT_TAIL(&xendevs, xendev, next);
@@ -277,10 +278,10 @@ static struct XenDevice *xen_be_del_xendev(int dom, int dev)
             qemu_free(xendev->fe);
         }
 
-        if (xendev->evtchndev >= 0) {
+        if (xendev->evtchndev != XC_HANDLER_INITIAL_VALUE) {
             xc_evtchn_close(xendev->evtchndev);
         }
-        if (xendev->gnttabdev >= 0) {
+        if (xendev->gnttabdev != XC_HANDLER_INITIAL_VALUE) {
             xc_gnttab_close(xendev->gnttabdev);
         }
 
@@ -664,8 +665,8 @@ int xen_be_init(void)
         goto err;
     }
 
-    xen_xc = xc_interface_open();
-    if (xen_xc == -1) {
+    xen_xc = xen_xc_interface_open(0, 0, 0);
+    if (xen_xc == XC_HANDLER_INITIAL_VALUE) {
         xen_be_printf(NULL, 0, "can't open xen interface\n");
         goto err;
     }

hw/xen_backend.h

@@ -45,8 +45,8 @@ struct XenDevice {
     int                remote_port;
     int                local_port;
 
-    int                evtchndev;
-    int                gnttabdev;
+    XenEvtchn          evtchndev;
+    XenGnttab          gnttabdev;
 
     struct XenDevOps   *ops;
     QTAILQ_ENTRY(XenDevice) next;
@@ -55,7 +55,7 @@ struct XenDevice {
 /* ------------------------------------------------------------- */
 
 /* variables */
-extern int xen_xc;
+extern XenXC xen_xc;
 extern struct xs_handle *xenstore;
 extern const char *xen_protocol;
 

hw/xen_common.h

@@ -1,6 +1,8 @@
 #ifndef QEMU_HW_XEN_COMMON_H
 #define QEMU_HW_XEN_COMMON_H 1
 
+#include "config-host.h"
+
 #include <stddef.h>
 #include <inttypes.h>
 
@@ -13,22 +15,87 @@
 #include "qemu-queue.h"
 
 /*
- * tweaks needed to build with different xen versions
- *  0x00030205 -> 3.1.0
- *  0x00030207 -> 3.2.0
- *  0x00030208 -> unstable
+ * We don't support Xen prior to 3.3.0.
  */
-#include <xen/xen-compat.h>
-#if __XEN_LATEST_INTERFACE_VERSION__ < 0x00030205
-# define evtchn_port_or_error_t int
-#endif
-#if __XEN_LATEST_INTERFACE_VERSION__ < 0x00030207
-# define xc_map_foreign_pages xc_map_foreign_batch
+
+/* Xen before 4.0 */
+#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 400
+static inline void *xc_map_foreign_bulk(int xc_handle, uint32_t dom, int prot,
+                                        xen_pfn_t *arr, int *err,
+                                        unsigned int num)
+{
+    return xc_map_foreign_batch(xc_handle, dom, prot, arr, num);
+}
 #endif
-#if __XEN_LATEST_INTERFACE_VERSION__ < 0x00030208
-# define xen_mb()  mb()
-# define xen_rmb() rmb()
-# define xen_wmb() wmb()
+
+
+/* Xen before 4.1 */
+#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 410
+
+typedef int XenXC;
+typedef int XenEvtchn;
+typedef int XenGnttab;
+
+#  define XC_INTERFACE_FMT "%i"
+#  define XC_HANDLER_INITIAL_VALUE    -1
+
+static inline XenEvtchn xen_xc_evtchn_open(void *logger,
+                                           unsigned int open_flags)
+{
+    return xc_evtchn_open();
+}
+
+static inline XenGnttab xen_xc_gnttab_open(void *logger,
+                                           unsigned int open_flags)
+{
+    return xc_gnttab_open();
+}
+
+static inline XenXC xen_xc_interface_open(void *logger, void *dombuild_logger,
+                                          unsigned int open_flags)
+{
+    return xc_interface_open();
+}
+
+static inline int xc_fd(int xen_xc)
+{
+    return xen_xc;
+}
+
+
+/* Xen 4.1 */
+#else
+
+typedef xc_interface *XenXC;
+typedef xc_evtchn *XenEvtchn;
+typedef xc_gnttab *XenGnttab;
+
+#  define XC_INTERFACE_FMT "%p"
+#  define XC_HANDLER_INITIAL_VALUE    NULL
+
+static inline XenEvtchn xen_xc_evtchn_open(void *logger,
+                                           unsigned int open_flags)
+{
+    return xc_evtchn_open(logger, open_flags);
+}
+
+static inline XenGnttab xen_xc_gnttab_open(void *logger,
+                                           unsigned int open_flags)
+{
+    return xc_gnttab_open(logger, open_flags);
+}
+
+static inline XenXC xen_xc_interface_open(void *logger, void *dombuild_logger,
+                                          unsigned int open_flags)
+{
+    return xc_interface_open(logger, dombuild_logger, open_flags);
+}
+
+/* FIXME There is now way to have the xen fd */
+static inline int xc_fd(xc_interface *xen_xc)
+{
+    return -1;
+}
 #endif
 
 #endif /* QEMU_HW_XEN_COMMON_H */

hw/xen_disk.c

@@ -242,7 +242,7 @@ err:
 
 static void ioreq_unmap(struct ioreq *ioreq)
 {
-    int gnt = ioreq->blkdev->xendev.gnttabdev;
+    XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev;
     int i;
 
     if (ioreq->v.niov == 0) {
@@ -275,7 +275,7 @@ static void ioreq_unmap(struct ioreq *ioreq)
 
 static int ioreq_map(struct ioreq *ioreq)
 {
-    int gnt = ioreq->blkdev->xendev.gnttabdev;
+    XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev;
     int i;
 
     if (ioreq->v.niov == 0) {

hw/xen_domainbuild.c

@@ -175,8 +175,9 @@ static int xen_domain_watcher(void)
     for (i = 3; i < n; i++) {
         if (i == fd[0])
             continue;
-        if (i == xen_xc)
+        if (i == xc_fd(xen_xc)) {
             continue;
+        }
         close(i);
     }