libxc: fix link error of xc_save on ia64

The suspend event channel functions are arch independent code
which xc_save uses.
The changeset of 19382:a5f497f02e34 cause link error on ia64.
This patch moves the functions into arch common file from
x86 specific file xc_domain_save.c

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>

1 files changed, 117 insertions, 0 deletions

diff --git a/tools/libxc/xc_suspend.c b/tools/libxc/xc_suspend.c
new file mode 100644
index 0000000000..c0ab75762d
--- /dev/null
+++ b/tools/libxc/xc_suspend.c
@@ -0,0 +1,117 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file "COPYING" in the main directory of
+ * this archive for more details.
+ */
+
+#include "xc_private.h"
+#include "xenguest.h"
+
+#define SUSPEND_LOCK_FILE "/var/lib/xen/suspend_evtchn_lock.d"
+static int lock_suspend_event(void)
+{
+    int fd, rc;
+    mode_t mask;
+    char buf[128];
+
+    mask = umask(022);
+    fd = open(SUSPEND_LOCK_FILE, O_CREAT | O_EXCL | O_RDWR, 0666);
+    if (fd < 0)
+    {
+        ERROR("Can't create lock file for suspend event channel\n");
+        return -EINVAL;
+    }
+    umask(mask);
+    snprintf(buf, sizeof(buf), "%10ld", (long)getpid());
+
+    rc = write_exact(fd, buf, strlen(buf));
+    close(fd);
+
+    return rc;
+}
+
+static int unlock_suspend_event(void)
+{
+    int fd, pid, n;
+    char buf[128];
+
+    fd = open(SUSPEND_LOCK_FILE, O_RDWR);
+
+    if (fd < 0)
+        return -EINVAL;
+
+    n = read(fd, buf, 127);
+
+    close(fd);
+
+    if (n > 0)
+    {
+        sscanf(buf, "%d", &pid);
+        /* We are the owner, so we can simply delete the file */
+        if (pid == getpid())
+        {
+            unlink(SUSPEND_LOCK_FILE);
+            return 0;
+        }
+    }
+
+    return -EPERM;
+}
+
+int xc_await_suspend(int xce, int suspend_evtchn)
+{
+    int rc;
+
+    do {
+        rc = xc_evtchn_pending(xce);
+        if (rc < 0) {
+            ERROR("error polling suspend notification channel: %d", rc);
+            return -1;
+        }
+    } while (rc != suspend_evtchn);
+
+    /* harmless for one-off suspend */
+    if (xc_evtchn_unmask(xce, suspend_evtchn) < 0)
+        ERROR("failed to unmask suspend notification channel: %d", rc);
+
+    return 0;
+}
+
+int xc_suspend_evtchn_release(int xce, int suspend_evtchn)
+{
+    if (suspend_evtchn >= 0)
+        xc_evtchn_unbind(xce, suspend_evtchn);
+
+    return unlock_suspend_event();
+}
+
+int xc_suspend_evtchn_init(int xc, int xce, int domid, int port)
+{
+    int rc, suspend_evtchn = -1;
+
+    if (lock_suspend_event())
+        return -EINVAL;
+
+    suspend_evtchn = xc_evtchn_bind_interdomain(xce, domid, port);
+    if (suspend_evtchn < 0) {
+        ERROR("failed to bind suspend event channel: %d", suspend_evtchn);
+        goto cleanup;
+    }
+
+    rc = xc_domain_subscribe_for_suspend(xc, domid, port);
+    if (rc < 0) {
+        ERROR("failed to subscribe to domain: %d", rc);
+        goto cleanup;
+    }
+
+    /* event channel is pending immediately after binding */
+    xc_await_suspend(xce, suspend_evtchn);
+
+    return suspend_evtchn;
+
+cleanup:
+    if (suspend_evtchn > 0)
+        xc_suspend_evtchn_release(xce, suspend_evtchn);
+
+    return -1;
+}