36888c6335
This commit causes the watchdog timer to be reset when a guest is
hard-rebooted.
The failure case previously was as follows:
(a) guest boots, watchdog is enabled
(b) guest does a reset eg:
echo 'b' > /proc/sysrq-trigger
(note that an ordinary /sbin/reboot wouldn't hit this case
since as the watchdog daemon is shut down, the daemon would
properly disable the watchdog device)
(c) the reboot takes longer than the remaining time on the
watchdog
(d) the watchdog therefore fires during the reboot
(e) probably the VM would just reboot again at this point which
is pretty benign, but it could depend on the action that the
user had selected for the watchdog
Now we use the qdev reset function to register a reset handler
which disables the timer. Note the handler is called _either_
just after init _or_ when the guest reboots.
In the i6300esb case there is a small refactoring of the code so
that the device's internal state is now fully restored to defaults
on a reboot.
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
138 lines
3.5 KiB
C
138 lines
3.5 KiB
C
/*
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* Virtual hardware watchdog.
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*
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* Copyright (C) 2009 Red Hat Inc.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*
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* By Richard W.M. Jones (rjones@redhat.com).
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*/
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#include "qemu-common.h"
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#include "qemu-timer.h"
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#include "watchdog.h"
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#include "hw.h"
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#include "isa.h"
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#include "pc.h"
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/*#define IB700_DEBUG 1*/
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#ifdef IB700_DEBUG
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#define ib700_debug(fs,...) \
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fprintf(stderr,"ib700: %s: "fs,__func__,##__VA_ARGS__)
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#else
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#define ib700_debug(fs,...)
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#endif
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typedef struct IB700state {
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ISADevice dev;
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QEMUTimer *timer;
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} IB700State;
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/* This is the timer. We use a global here because the watchdog
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* code ensures there is only one watchdog (it is located at a fixed,
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* unchangable IO port, so there could only ever be one anyway).
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*/
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/* A write to this register enables the timer. */
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static void ib700_write_enable_reg(void *vp, uint32_t addr, uint32_t data)
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{
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IB700State *s = vp;
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static int time_map[] = {
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30, 28, 26, 24, 22, 20, 18, 16,
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14, 12, 10, 8, 6, 4, 2, 0
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};
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int64 timeout;
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ib700_debug("addr = %x, data = %x\n", addr, data);
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timeout = (int64_t) time_map[data & 0xF] * get_ticks_per_sec();
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qemu_mod_timer(s->timer, qemu_get_clock (vm_clock) + timeout);
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}
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/* A write (of any value) to this register disables the timer. */
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static void ib700_write_disable_reg(void *vp, uint32_t addr, uint32_t data)
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{
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IB700State *s = vp;
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ib700_debug("addr = %x, data = %x\n", addr, data);
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qemu_del_timer(s->timer);
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}
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/* This is called when the watchdog expires. */
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static void ib700_timer_expired(void *vp)
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{
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IB700State *s = vp;
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ib700_debug("watchdog expired\n");
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watchdog_perform_action();
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qemu_del_timer(s->timer);
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}
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static const VMStateDescription vmstate_ib700 = {
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.name = "ib700_wdt",
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.version_id = 0,
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.minimum_version_id = 0,
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.minimum_version_id_old = 0,
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.fields = (VMStateField []) {
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VMSTATE_TIMER(timer, IB700State),
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VMSTATE_END_OF_LIST()
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}
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};
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static int wdt_ib700_init(ISADevice *dev)
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{
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IB700State *s = DO_UPCAST(IB700State, dev, dev);
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ib700_debug("watchdog init\n");
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s->timer = qemu_new_timer(vm_clock, ib700_timer_expired, s);
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register_ioport_write(0x441, 2, 1, ib700_write_disable_reg, s);
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register_ioport_write(0x443, 2, 1, ib700_write_enable_reg, s);
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return 0;
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}
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static void wdt_ib700_reset(DeviceState *dev)
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{
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IB700State *s = DO_UPCAST(IB700State, dev.qdev, dev);
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ib700_debug("watchdog reset\n");
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qemu_del_timer(s->timer);
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}
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static WatchdogTimerModel model = {
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.wdt_name = "ib700",
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.wdt_description = "iBASE 700",
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};
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static ISADeviceInfo wdt_ib700_info = {
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.qdev.name = "ib700",
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.qdev.size = sizeof(IB700State),
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.qdev.vmsd = &vmstate_ib700,
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.qdev.reset = wdt_ib700_reset,
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.init = wdt_ib700_init,
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};
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static void wdt_ib700_register_devices(void)
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{
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watchdog_add_model(&model);
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isa_qdev_register(&wdt_ib700_info);
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}
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device_init(wdt_ib700_register_devices);
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