[Xen-devel] [PATCH 1/2] libxc: add xc_wallclock_sync()

[David Vrabel <david.vrabel@xxxxxxxxxx>]

From: David Vrabel <david.vrabel@xxxxxxxxxx>

xc_wallclock_sync() synchronizes the Xen wallclock to system time.

This requires a Linux kernel with a privcmd device that provides the
IOCTL_PRIVCMD_SYNC_WALLCLOCK ioctl.

Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
---
 tools/include/xen-sys/Linux/privcmd.h |    8 ++++++++
 tools/libxc/Makefile                  |    1 +
 tools/libxc/xc_linux_osdep.c          |    7 +++++++
 tools/libxc/xc_wallclock.c            |   23 +++++++++++++++++++++++
 tools/libxc/xenctrl.h                 |    5 +++++
 tools/libxc/xenctrlosdep.h            |    2 ++
 6 files changed, 46 insertions(+), 0 deletions(-)
 create mode 100644 tools/libxc/xc_wallclock.c

diff --git a/tools/include/xen-sys/Linux/privcmd.h 
b/tools/include/xen-sys/Linux/privcmd.h
index d35aac9..55765d1 100644
--- a/tools/include/xen-sys/Linux/privcmd.h
+++ b/tools/include/xen-sys/Linux/privcmd.h
@@ -76,6 +76,12 @@ typedef struct privcmd_mmapbatch_v2 {
  * @cmd: IOCTL_PRIVCMD_HYPERCALL
  * @arg: &privcmd_hypercall_t
  * Return: Value returned from execution of the specified hypercall.
+ *
+ * @cmd: IOCTL_PRIVCMD_SYNC_WALLCLOCK
+ * @arg: Unused.
+ * Synchronizes the Xen wallclock with the current system time.
+ * Return: 0 on success, or -1 on error with errno set to EPERM or
+ * EACCES.
  */
 #define IOCTL_PRIVCMD_HYPERCALL                                        \
        _IOC(_IOC_NONE, 'P', 0, sizeof(privcmd_hypercall_t))
@@ -85,5 +91,7 @@ typedef struct privcmd_mmapbatch_v2 {
        _IOC(_IOC_NONE, 'P', 3, sizeof(privcmd_mmapbatch_t))
 #define IOCTL_PRIVCMD_MMAPBATCH_V2                             \
        _IOC(_IOC_NONE, 'P', 4, sizeof(privcmd_mmapbatch_v2_t))
+#define IOCTL_PRIVCMD_SYNC_WALLCLOCK                           \
+       _IOC(_IOC_NONE, 'P', 5, 0)
 
 #endif /* __LINUX_PUBLIC_PRIVCMD_H__ */
diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index d44abf9..601ea4b 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -31,6 +31,7 @@ CTRL_SRCS-y       += xc_mem_access.c
 CTRL_SRCS-y       += xc_memshr.c
 CTRL_SRCS-y       += xc_hcall_buf.c
 CTRL_SRCS-y       += xc_foreign_memory.c
+CTRL_SRCS-y       += xc_wallclock.c
 CTRL_SRCS-y       += xtl_core.c
 CTRL_SRCS-y       += xtl_logger_stdio.c
 CTRL_SRCS-$(CONFIG_X86) += xc_pagetab.c
diff --git a/tools/libxc/xc_linux_osdep.c b/tools/libxc/xc_linux_osdep.c
index 787e742..7c73b66 100644
--- a/tools/libxc/xc_linux_osdep.c
+++ b/tools/libxc/xc_linux_osdep.c
@@ -412,6 +412,11 @@ static void *linux_privcmd_map_foreign_ranges(xc_interface 
*xch, xc_osdep_handle
     return ret;
 }
 
+static int linux_wallclock_sync(xc_interface *xch, xc_osdep_handle h)
+{
+    return ioctl(h, IOCTL_PRIVCMD_SYNC_WALLCLOCK, NULL);
+}
+
 static struct xc_osdep_ops linux_privcmd_ops = {
     .open = &linux_privcmd_open,
     .close = &linux_privcmd_close,
@@ -426,6 +431,8 @@ static struct xc_osdep_ops linux_privcmd_ops = {
         .map_foreign_bulk = &linux_privcmd_map_foreign_bulk,
         .map_foreign_range = &linux_privcmd_map_foreign_range,
         .map_foreign_ranges = &linux_privcmd_map_foreign_ranges,
+
+        .wallclock_sync = linux_wallclock_sync,
     },
 };
 
diff --git a/tools/libxc/xc_wallclock.c b/tools/libxc/xc_wallclock.c
new file mode 100644
index 0000000..5119b2a
--- /dev/null
+++ b/tools/libxc/xc_wallclock.c
@@ -0,0 +1,23 @@
+/******************************************************************************
+ * xc_wallclock.c
+ *
+ * API for the wallclock.
+ *
+ * Copyright (C) 2012, Citrix Systems (UK) Ltd.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ */
+
+#include "xc_private.h"
+
+int xc_wallclock_sync(xc_interface *xch)
+{
+    if (xch->ops->u.privcmd.wallclock_sync == NULL) {
+        errno = ENOSYS;
+        return -1;
+    }
+    return xch->ops->u.privcmd.wallclock_sync(xch, xch->ops_handle);
+}
diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index 7eb5743..f9bb21b 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -2224,4 +2224,9 @@ int xc_compression_uncompress_page(xc_interface *xch, 
char *compbuf,
                                   unsigned long compbuf_size,
                                   unsigned long *compbuf_pos, char *dest);
 
+/**
+ * Synchronize Xen's wallclock with the current system time.
+ */
+int xc_wallclock_sync(xc_interface *xch);
+
 #endif /* XENCTRL_H */
diff --git a/tools/libxc/xenctrlosdep.h b/tools/libxc/xenctrlosdep.h
index a36c4aa..3aa3360 100644
--- a/tools/libxc/xenctrlosdep.h
+++ b/tools/libxc/xenctrlosdep.h
@@ -89,6 +89,8 @@ struct xc_osdep_ops
             void *(*map_foreign_ranges)(xc_interface *xch, xc_osdep_handle h, 
uint32_t dom, size_t size, int prot,
                                         size_t chunksize, privcmd_mmap_entry_t 
entries[],
                                         int nentries);
+
+            int (*wallclock_sync)(xc_interface *xch, xc_osdep_handle h);
         } privcmd;
         struct {
             int (*fd)(xc_evtchn *xce, xc_osdep_handle h);
-- 
1.7.2.5


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