This is the toolstack side of the Linux wallclock fixes. A new libxc call, xc_wallclock_sync() is provided and a new command line utility (xen-wallclock) makes use of this. I also considered making libxl call xc_wallclock_sync() during domain creation but wasn''t sure if this was sensible or whether there needed to be an xl configuration option to enable/disable this behaviour. Any comments? David
From: David Vrabel <david.vrabel@citrix.com>
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@citrix.com>
---
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
From: David Vrabel <david.vrabel@citrix.com>
Add the xen-wallclock command for synchronizing the Xen wallclock to
system time. The command is similar to the hwclock command for
synchronizing the hardware RTC and takes a similar --systowc command
line option.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
.gitignore | 1 +
.hgignore | 1 +
tools/misc/Makefile | 8 +++-
tools/misc/xen-wallclock.c | 87 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 95 insertions(+), 2 deletions(-)
create mode 100644 tools/misc/xen-wallclock.c
diff --git a/.gitignore b/.gitignore
index f6edc43..a62abd2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -196,6 +196,7 @@ tools/misc/xc_shadow
tools/misc/xen_cpuperf
tools/misc/xen-detect
tools/misc/xen-tmem-list-parse
+tools/misc/xen-wallclock
tools/misc/xenperf
tools/misc/xenpm
tools/misc/xen-hvmctx
diff --git a/.hgignore b/.hgignore
index 344792a..3b6f747 100644
--- a/.hgignore
+++ b/.hgignore
@@ -198,6 +198,7 @@
^tools/misc/xen-hptool$
^tools/misc/xen-hvmcrash$
^tools/misc/xen-tmem-list-parse$
+^tools/misc/xen-wallclock$
^tools/misc/xenperf$
^tools/misc/xenpm$
^tools/misc/xen-hvmctx$
diff --git a/tools/misc/Makefile b/tools/misc/Makefile
index 22e60fd..456d1ad 100644
--- a/tools/misc/Makefile
+++ b/tools/misc/Makefile
@@ -9,7 +9,8 @@ CFLAGS += $(CFLAGS_libxenstore)
HDRS = $(wildcard *.h)
-TARGETS-y := xenperf xenpm xen-tmem-list-parse gtraceview gtracestat
xenlockprof xenwatchdogd
+TARGETS-y := xenperf xenpm xen-tmem-list-parse gtraceview gtracestat
xenlockprof xenwatchdogd \
+ xen-wallclock
TARGETS-$(CONFIG_X86) += xen-detect xen-hvmctx xen-hvmcrash xen-lowmemd
TARGETS-$(CONFIG_MIGRATE) += xen-hptool
TARGETS := $(TARGETS-y)
@@ -22,7 +23,7 @@ INSTALL_BIN-y := xencons
INSTALL_BIN-$(CONFIG_X86) += xen-detect
INSTALL_BIN := $(INSTALL_BIN-y)
-INSTALL_SBIN-y := xm xen-bugtool xen-python-path xend xenperf xsview xenpm
xen-tmem-list-parse gtraceview gtracestat xenlockprof xenwatchdogd xen-ringwatch
+INSTALL_SBIN-y := xm xen-bugtool xen-python-path xend xenperf xsview xenpm
xen-tmem-list-parse gtraceview gtracestat xenlockprof xenwatchdogd xen-ringwatch
xen-wallclock
INSTALL_SBIN-$(CONFIG_X86) += xen-hvmctx xen-hvmcrash xen-lowmemd
INSTALL_SBIN-$(CONFIG_MIGRATE) += xen-hptool
INSTALL_SBIN := $(INSTALL_SBIN-y)
@@ -85,4 +86,7 @@ xen-lowmemd: xen-lowmemd.o
gtraceview: gtraceview.o
$(CC) $(LDFLAGS) -o $@ $< $(CURSES_LIBS) $(APPEND_LDFLAGS)
+xen-wallclock: xen-wallclock.o
+ $(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(APPEND_LDFLAGS)
+
-include $(DEPS)
diff --git a/tools/misc/xen-wallclock.c b/tools/misc/xen-wallclock.c
new file mode 100644
index 0000000..e4af166
--- /dev/null
+++ b/tools/misc/xen-wallclock.c
@@ -0,0 +1,87 @@
+/*
+ * xen-wallclock.c: manage the Xen wallclock.
+ * Copyright (C) 2012, Citrix Systems (UK) Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <getopt.h>
+
+#include <xenctrl.h>
+
+static const char *exe_name;
+
+static void usage(FILE *f)
+{
+ fprintf(f, "Usage: %s --systowc\n", exe_name);
+}
+
+static void help(void)
+{
+ usage(stdout);
+ printf("Synchronize the Xen wallclock with system time.\n"
+ "\n"
+ " -w, --systowc synchronize wallclock with system time\n"
+ " --help display this help and exit\n");
+ exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+ const static char sopts[] = "w";
+ const static struct option lopts[] = {
+ { "help", 0, NULL, 0 },
+ { "systowc", 0, NULL, ''w'' },
+ { 0, 0, NULL, 0 },
+ };
+ int opt, opt_idx;
+
+ int systowc = 0;
+ xc_interface *xch;
+
+ exe_name = argv[0];
+
+ while ( (opt = getopt_long(argc, argv, sopts, lopts, &opt_idx)) != -1 )
+ {
+ switch ( opt )
+ {
+ case ''w'':
+ systowc = 1;
+ break;
+ case 0:
+ switch (opt_idx)
+ {
+ case 0:
+ help();
+ }
+ break;
+ default:
+ usage(stderr);
+ exit(1);
+ }
+ }
+
+ /* Valid combination of options? i.e., --systowc */
+ if (!systowc)
+ {
+ usage(stderr);
+ exit(1);
+ }
+
+ xch = xc_interface_open(NULL, NULL, 0);
+ if (xch == NULL)
+ {
+ exit(1);
+ }
+ xc_wallclock_sync(xch);
+ xc_interface_close(xch);
+
+ return 0;
+}
--
1.7.2.5
On Fri, 2012-10-12 at 14:02 +0100, David Vrabel wrote:> +int main(int argc, char *argv[]) > +{ > + const static char sopts[] = "w"; > + const static struct option lopts[] = { > + { "help", 0, NULL, 0 }, > + { "systowc", 0, NULL, ''w'' }, > + { 0, 0, NULL, 0 }, > + }; > + int opt, opt_idx; > + > + int systowc = 0; > + xc_interface *xch; > + > + exe_name = argv[0]; > + > + while ( (opt = getopt_long(argc, argv, sopts, lopts, &opt_idx)) != -1 ) > + { > + switch ( opt ) > + { > + case ''w'': > + systowc = 1; > + break; > + case 0: > + switch (opt_idx) > + { > + case 0: > + help(); > + } > + break; > + default: > + usage(stderr); > + exit(1); > + } > + } > + > + /* Valid combination of options? i.e., --systowc */ > + if (!systowc) > + { > + usage(stderr); > + exit(1); > + } > + > + xch = xc_interface_open(NULL, NULL, 0); > + if (xch == NULL) > + {I forget: Does xc_interface_open log on error?> + exit(1); > + } > + xc_wallclock_sync(xch);Worth logging if this fails? I suppose we want to hold off on this and the first patch until the Linux side is agreed and committed?> + xc_interface_close(xch); > + > + return 0; > +}
On 15/10/12 10:35, Ian Campbell wrote:> On Fri, 2012-10-12 at 14:02 +0100, David Vrabel wrote: >> +int main(int argc, char *argv[]) >> +{ >> + const static char sopts[] = "w"; >> + const static struct option lopts[] = { >> + { "help", 0, NULL, 0 }, >> + { "systowc", 0, NULL, ''w'' }, >> + { 0, 0, NULL, 0 }, >> + }; >> + int opt, opt_idx; >> + >> + int systowc = 0; >> + xc_interface *xch; >> + >> + exe_name = argv[0]; >> + >> + while ( (opt = getopt_long(argc, argv, sopts, lopts, &opt_idx)) != -1 ) >> + { >> + switch ( opt ) >> + { >> + case ''w'': >> + systowc = 1; >> + break; >> + case 0: >> + switch (opt_idx) >> + { >> + case 0: >> + help(); >> + } >> + break; >> + default: >> + usage(stderr); >> + exit(1); >> + } >> + } >> + >> + /* Valid combination of options? i.e., --systowc */ >> + if (!systowc) >> + { >> + usage(stderr); >> + exit(1); >> + } >> + >> + xch = xc_interface_open(NULL, NULL, 0); >> + if (xch == NULL) >> + { > > I forget: Does xc_interface_open log on error?Yes.>> + exit(1); >> + } >> + xc_wallclock_sync(xch); > > Worth logging if this fails?Yes.> I suppose we want to hold off on this and the first patch until the > Linux side is agreed and committed?Yes.>> + xc_interface_close(xch); >> + >> + return 0; >> +}David