Here's the promised patch against a recent 2.01 snapshot to allow you to
send sysrqs to running Linux kernels. I went with Keir's suggestion of
adding a sub-reason code to the shutdown message with a 1-byte payload
specifying which key was pressed. Hope it's acceptable for the main
tree; I will happily alter it to spec if any of the maintainers have
suggestions for better structuring it.
It adds the CONFIG_MAGIC_SYSRQ option to the Linux kernel which you need
to turn on for a guest to work with it, then you can just do e.g. "xm
sysrq domainname s" to sync your discs.
cheers,
--
Matthew Bloch Bytemark Hosting
http://www.bytemark.co.uk/
phone UK: 0845 004 3 004 US: 1-877 BYTEMAR
Dedicated Linux hosts from 15ukp ($26) per month
diff -urN xen-2.0/linux-2.6.9-xen-sparse/arch/xen/Kconfig
xen-2.0-sysrq/linux-2.6.9-xen-sparse/arch/xen/Kconfig
--- xen-2.0/linux-2.6.9-xen-sparse/arch/xen/Kconfig 2004-11-17
22:51:41.000000000 +0000
+++ xen-2.0-sysrq/linux-2.6.9-xen-sparse/arch/xen/Kconfig 2004-12-08
15:03:23.000000000 +0000
@@ -164,3 +164,20 @@
source "crypto/Kconfig"
source "lib/Kconfig"
+
+menu "Kernel hacking"
+
+config MAGIC_SYSRQ
+ bool "Magic SysRq key"
+ help
+ If you say Y here, you will have some control over the system even
+ if the system crashes for example during kernel debugging (e.g., you
+ will be able to flush the buffer cache to disk, reboot the system
+ immediately or dump some status information). This is accomplished
+ by pressing various keys while holding SysRq (Alt+PrintScreen). It
+ also works on a serial console (on PC hardware at least), if you
+ send a BREAK and then within 5 seconds a command keypress. The
+ keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
+ unless you really know what this hack does.
+
+endmenu
diff -urN xen-2.0/linux-2.6.9-xen-sparse/arch/xen/kernel/reboot.c
xen-2.0-sysrq/linux-2.6.9-xen-sparse/arch/xen/kernel/reboot.c
--- xen-2.0/linux-2.6.9-xen-sparse/arch/xen/kernel/reboot.c 2004-11-17
22:51:41.000000000 +0000
+++ xen-2.0-sysrq/linux-2.6.9-xen-sparse/arch/xen/kernel/reboot.c
2004-12-08 15:03:23.000000000 +0000
@@ -8,6 +8,7 @@
#include <linux/unistd.h>
#include <linux/module.h>
#include <linux/reboot.h>
+#include <linux/sysrq.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm-xen/ctrl_if.h>
@@ -53,6 +54,7 @@
/* Ignore multiple shutdown requests. */
static int shutting_down = -1;
+static int pending_sysrq = -1;
static void __do_suspend(void)
{
@@ -214,9 +216,22 @@
}
}
+static void __sysrq_handler(void *unused)
+{
+#ifndef CONFIG_MAGIC_SYSRQ
+ printk("CONFIG_MAGIC_SYSRQ not compiled in, will ignore!\n");
+#else
+ handle_sysrq(pending_sysrq, NULL, NULL);
+ pending_sysrq = -1;
+#endif
+}
+
static void shutdown_handler(ctrl_msg_t *msg, unsigned long id)
{
static DECLARE_WORK(shutdown_work, __shutdown_handler, NULL);
+ static DECLARE_WORK(sysrq_work, __sysrq_handler, NULL);
+
+ printk("msg->subtype = %d, msg->msg[0] = %d", msg->subtype, msg->msg[0]);
if ( (shutting_down == -1) &&
((msg->subtype == CMSG_SHUTDOWN_POWEROFF) ||
@@ -226,6 +241,12 @@
shutting_down = msg->subtype;
schedule_work(&shutdown_work);
}
+ else if (msg->subtype == CMSG_SHUTDOWN_SYSRQ)
+ {
+ /* sysrqs are allowed during shutdown in case shutdown stuffs up */
+ pending_sysrq = msg->msg[0];
+ schedule_work(&sysrq_work);
+ }
else
{
printk("Ignore spurious shutdown request\n");
diff -urN xen-2.0/tools/python/xen/xend/XendClient.py
xen-2.0-sysrq/tools/python/xen/xend/XendClient.py
--- xen-2.0/tools/python/xen/xend/XendClient.py 2004-11-17 22:51:40.000000000
+0000
+++ xen-2.0-sysrq/tools/python/xen/xend/XendClient.py 2004-12-08
15:03:23.000000000 +0000
@@ -228,10 +228,11 @@
return self.xendPost(self.domainurl(id),
{'op' : 'pause' })
- def xend_domain_shutdown(self, id, reason):
+ def xend_domain_shutdown(self, id, reason, key=None):
return self.xendPost(self.domainurl(id),
{'op' : 'shutdown',
- 'reason' : reason })
+ 'reason' : reason,
+ 'key' : key })
def xend_domain_destroy(self, id, reason):
return self.xendPost(self.domainurl(id),
diff -urN xen-2.0/tools/python/xen/xend/XendDomain.py
xen-2.0-sysrq/tools/python/xen/xend/XendDomain.py
--- xen-2.0/tools/python/xen/xend/XendDomain.py 2004-11-17 22:51:42.000000000
+0000
+++ xen-2.0-sysrq/tools/python/xen/xend/XendDomain.py 2004-12-09
10:47:57.000000000 +0000
@@ -455,7 +455,7 @@
except Exception, ex:
raise XendError(str(ex))
- def domain_shutdown(self, id, reason='poweroff'):
+ def domain_shutdown(self, id, reason='poweroff', key=None):
"""Shutdown domain (nicely).
- poweroff: restart according to exit code and restart mode
- reboot: restart on exit
@@ -474,7 +474,7 @@
eserver.inject('xend.domain.shutdown', [dominfo.name, dominfo.id,
reason])
if reason == 'halt':
reason = 'poweroff'
- val = xend.domain_shutdown(dominfo.id, reason)
+ val = xend.domain_shutdown(dominfo.id, reason, key)
self.refresh_schedule()
return val
diff -urN xen-2.0/tools/python/xen/xend/server/SrvDaemon.py
xen-2.0-sysrq/tools/python/xen/xend/server/SrvDaemon.py
--- xen-2.0/tools/python/xen/xend/server/SrvDaemon.py 2004-11-17
22:51:47.000000000 +0000
+++ xen-2.0-sysrq/tools/python/xen/xend/server/SrvDaemon.py 2004-12-09
10:51:57.000000000 +0000
@@ -711,14 +711,14 @@
raise XendError('Invalid console id')
console.disconnect()
- def domain_shutdown(self, dom, reason):
+ def domain_shutdown(self, dom, reason, key=None):
"""Shutdown a domain.
"""
dom = int(dom)
ctrl = self.domainCF.getController(dom)
if not ctrl:
raise XendError('No domain controller: %s' % dom)
- ctrl.shutdown(reason)
+ ctrl.shutdown(reason, key)
return 0
def domain_mem_target_set(self, dom, target):
diff -urN xen-2.0/tools/python/xen/xend/server/SrvDomain.py
xen-2.0-sysrq/tools/python/xen/xend/server/SrvDomain.py
--- xen-2.0/tools/python/xen/xend/server/SrvDomain.py 2004-11-17
22:51:47.000000000 +0000
+++ xen-2.0-sysrq/tools/python/xen/xend/server/SrvDomain.py 2004-12-08
17:24:07.000000000 +0000
@@ -47,7 +47,8 @@
def op_shutdown(self, op, req):
fn = FormFn(self.xd.domain_shutdown,
[['dom', 'str'],
- ['reason', 'str']])
+ ['reason', 'str'],
+ ['key', 'int']])
val = fn(req.args, {'dom': self.dom.id})
req.setResponseCode(http.ACCEPTED)
req.setHeader("Location", "%s/.." % req.prePathURL())
diff -urN xen-2.0/tools/python/xen/xend/server/domain.py
xen-2.0-sysrq/tools/python/xen/xend/server/domain.py
--- xen-2.0/tools/python/xen/xend/server/domain.py 2004-11-17
22:51:43.000000000 +0000
+++ xen-2.0-sysrq/tools/python/xen/xend/server/domain.py 2004-12-08
17:20:02.000000000 +0000
@@ -28,7 +28,8 @@
"""
reasons = {'poweroff' : 'shutdown_poweroff_t',
'reboot' : 'shutdown_reboot_t',
- 'suspend' : 'shutdown_suspend_t' }
+ 'suspend' : 'shutdown_suspend_t',
+ 'sysrq' : 'shutdown_sysrq_t' }
def __init__(self, factory, dom):
controller.Controller.__init__(self, factory, dom)
@@ -36,16 +37,19 @@
self.addMethod(CMSG_MEM_REQUEST, 0, None)
self.registerChannel()
- def shutdown(self, reason):
+ def shutdown(self, reason, key=None):
"""Shutdown a domain.
reason shutdown reason
+ key sysrq key (only if reason is 'sysrq')
"""
msgtype = self.reasons.get(reason)
if not msgtype:
raise XendError('invalid reason:' + reason)
- msg = packMsg(msgtype, {})
- self.writeRequest(msg)
+ extra = {}
+ if reason == 'sysrq': extra['key'] = key
+ print extra
+ self.writeRequest(packMsg(msgtype, extra))
def mem_target_set(self, target):
"""Set domain memory target in pages.
diff -urN xen-2.0/tools/python/xen/xend/server/messages.py
xen-2.0-sysrq/tools/python/xen/xend/server/messages.py
--- xen-2.0/tools/python/xen/xend/server/messages.py 2004-11-17
22:51:42.000000000 +0000
+++ xen-2.0-sysrq/tools/python/xen/xend/server/messages.py 2004-12-08
15:03:23.000000000 +0000
@@ -197,10 +197,12 @@
CMSG_SHUTDOWN_POWEROFF = 0
CMSG_SHUTDOWN_REBOOT = 1
CMSG_SHUTDOWN_SUSPEND = 2
+CMSG_SHUTDOWN_SYSRQ = 3
STOPCODE_shutdown = 0
STOPCODE_reboot = 1
STOPCODE_suspend = 2
+STOPCODE_sysrq = 3
shutdown_formats = {
'shutdown_poweroff_t':
@@ -211,6 +213,9 @@
'shutdown_suspend_t':
(CMSG_SHUTDOWN, CMSG_SHUTDOWN_SUSPEND),
+
+ 'shutdown_sysrq_t':
+ (CMSG_SHUTDOWN, CMSG_SHUTDOWN_SYSRQ)
}
msg_formats.update(shutdown_formats)
diff -urN xen-2.0/tools/python/xen/xm/main.py
xen-2.0-sysrq/tools/python/xen/xm/main.py
--- xen-2.0/tools/python/xen/xm/main.py 2004-11-17 22:51:47.000000000 +0000
+++ xen-2.0-sysrq/tools/python/xen/xm/main.py 2004-12-08 15:03:23.000000000
+0000
@@ -11,7 +11,7 @@
from xen.xend import sxp
from xen.xend.XendClient import XendError, server
from xen.xend.XendClient import main as xend_client_main
-from xen.xm import create, destroy, migrate, shutdown
+from xen.xm import create, destroy, migrate, shutdown, sysrq
from xen.xm.opts import *
class Group:
@@ -401,6 +401,19 @@
xm.prog(ProgShutdown)
+class ProgSysrq(Prog):
+ group = 'domain'
+ name = "sysrq"
+ info = """Send a sysrq to a domain."""
+
+ def help(self, args):
+ sysrq.main([args[0], '-h'])
+
+ def main(self, args):
+ sysrq.main(args)
+
+xm.prog(ProgSysrq)
+
class ProgPause(Prog):
group = 'domain'
name = "pause"
diff -urN xen-2.0/tools/python/xen/xm/sysrq.py
xen-2.0-sysrq/tools/python/xen/xm/sysrq.py
--- xen-2.0/tools/python/xen/xm/sysrq.py 1970-01-01 01:00:00.000000000
+0100
+++ xen-2.0-sysrq/tools/python/xen/xm/sysrq.py 2004-12-08 17:17:38.000000000
+0000
@@ -0,0 +1,39 @@
+# (C) Matthew Bloch <matthew@xxxxxxxxxxxxxx> 2004
+
+"""Domain shutdown.
+"""
+import string
+import sys
+import time
+
+from xen.xend.XendClient import server
+from xen.xm.opts import *
+
+DOM0_NAME = 'Domain-0'
+DOM0_ID = '0'
+
+gopts = Opts(use="""[DOM] [letter]
+
+Sends a Linux sysrq to a domain.
+""")
+
+gopts.opt('help', short='h',
+ fn=set_true, default=0,
+ use="Print this help.")
+
+def sysrq(dom, req):
+ server.xend_domain_shutdown(dom, 'sysrq', req)
+
+def main(argv):
+ opts = gopts
+ args = opts.parse(argv)
+ if opts.vals.help:
+ opts.usage()
+ return
+
+ # no options for the moment
+ if len(args) < 1: opts.err('Missing domain')
+ if len(args) < 2: opts.err('Missing sysrq character')
+ dom = args[0]
+ req = ord(args[1][0])
+ sysrq(dom, req)
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