From mboxrd@z Thu Jan  1 00:00:00 1970
From: Laszlo Ersek <lersek@redhat.com>
Subject: xen-wdt questions
Date: Wed, 05 Oct 2011 15:08:40 +0200
Message-ID: <4E8C56D8.6060604@redhat.com>
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Cc: Jan Beulich <JBeulich@novell.com>
List-Id: xen-devel@lists.xenproject.org

Hi,

I tried to test xen-wdt (as of 066d6c7) with
Documentation/watchdog/src/watchdog-test.c:

(1) when the test tool is invoked as "./watchdog-test -d", it exercises
WDIOC_SETOPTIONS/WDIOS_DISABLECARD, prints "Watchdog card disabled.",
and then closes /dev/watchdog.

That ioctl stops the watchdog alright via the hypercall and zeroes out
the guets's "wdt", but in repsonse to the closure (since
"expect_release" is not set) the xen_wdt_release() function prints a
critical message to the console ("unexpected close, not stopping
watchdog!"), and tries to kick it again. (At this time the guest's
wdt.id is 0, and so xen_wdt_kick() returns -ENXIO, but xen_wdt_release()
ignorese it.) The watchdog is stopped for real and the domain is not
killed, but the KERN_CRIT message could be misleading.

(2) Additionally, the WDIOC_SETOPTIONS/WDIOS_DISABLECARD ioctl manages
to turn off the watchdog, even if nowayout=1 was passed to the xen-wdt
module. Is that intentional?

Thanks
Laszlo