[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v2 2/4] vl: Add option to avoid stopping VM upon guest panic
From: |
Alejandro Jimenez |
Subject: |
[PATCH v2 2/4] vl: Add option to avoid stopping VM upon guest panic |
Date: |
Wed, 9 Dec 2020 12:52:14 -0500 |
The current default action of pausing a guest after a panic event
is received leaves the responsibility to resume guest execution to the
management layer. The reasons for this behavior are discussed here:
https://lore.kernel.org/qemu-devel/52148F88.5000509@redhat.com/
However, in instances like the case of older guests (Linux and
Windows) using a pvpanic device but missing support for the
PVPANIC_CRASHLOADED event, and Windows guests using the hv-crash
enlightenment, it is desirable to allow the guests to continue
running after sending a PVPANIC_PANICKED event. This allows such
guests to proceed to capture a crash dump and automatically reboot
without intervention of a management layer.
Add an option to avoid stopping a VM after a panic event is received,
by passing:
-action panic=none
in the command line arguments, or during runtime by using an upcoming
QMP command.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
---
include/sysemu/sysemu.h | 1 +
qapi/run-state.json | 27 ++++++++++++++++++++++++++-
qemu-options.hx | 3 +++
softmmu/runstate-action.c | 22 ++++++++++++++++++++++
softmmu/vl.c | 14 +++++++++++---
5 files changed, 63 insertions(+), 4 deletions(-)
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 5480e61..863142e 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -45,6 +45,7 @@ extern int ctrl_grab;
extern int graphic_rotate;
extern int no_reboot;
extern int no_shutdown;
+extern int pause_on_panic;
extern int old_param;
extern int boot_menu;
extern bool boot_strict;
diff --git a/qapi/run-state.json b/qapi/run-state.json
index 6b033c1..27b62ce 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -337,12 +337,14 @@
#
# @shutdown: Guest shutdown
#
+# @panic: Guest has panicked
+#
# @watchdog: A watchdog device's timer has expired
#
# Since: 6.0
##
{ 'enum': 'RunStateEventType',
- 'data': [ 'reboot', 'shutdown', 'watchdog' ] }
+ 'data': [ 'reboot', 'shutdown', 'panic', 'watchdog' ] }
##
# @RunStateAction:
@@ -358,6 +360,7 @@
'data': {
'reboot': 'RunStateRebootAction',
'shutdown': 'RunStateShutdownAction',
+ 'panic': 'RunStatePanicAction',
'watchdog': 'RunStateWatchdogAction' } }
##
@@ -407,6 +410,28 @@
'data': [ 'pause', 'poweroff' ] }
##
+# @RunStatePanicAction:
+#
+# @action: Action taken by QEMU when guest panicks
+#
+# Since: 6.0
+##
+{ 'struct': 'RunStatePanicAction',
+ 'data': { 'action': 'PanicAction' } }
+
+##
+# @PanicAction:
+#
+# @none: Continue VM execution
+#
+# @pause: Pause the VM
+#
+# Since: 6.0
+##
+{ 'enum': 'PanicAction',
+ 'data': [ 'none', 'pause' ] }
+
+##
# @RunStateWatchdogAction:
#
# @action: Action taken by QEMU when watchdog device timer expires
diff --git a/qemu-options.hx b/qemu-options.hx
index a0d50f0..8b7d8bb 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3899,6 +3899,8 @@ DEF("action", HAS_ARG, QEMU_OPTION_action,
" action when guest reboots [default=none]\n"
"-action shutdown=poweroff|pause\n"
" action when guest shuts down [default=poweroff]\n"
+ "-action panic=pause|none\n"
+ " action when guest panics [default=pause]\n"
"-action watchdog=reset|shutdown|poweroff|inject-nmi|pause|debug|none\n"
" action when watchdog fires [default=reset]\n",
QEMU_ARCH_ALL)
@@ -3911,6 +3913,7 @@ SRST
Examples:
+ ``-action panic=none``
``-action reboot=shutdown,shutdown=pause``
``-watchdog i6300esb -action watchdog=pause``
diff --git a/softmmu/runstate-action.c b/softmmu/runstate-action.c
index f1fd457..a644d80 100644
--- a/softmmu/runstate-action.c
+++ b/softmmu/runstate-action.c
@@ -62,6 +62,24 @@ static void shutdown_set_action(ShutdownAction act, Error
**errp)
}
/*
+ * Set the internal state to react to a guest panic event
+ * as specified by the action parameter.
+ */
+static void panic_set_action(PanicAction action, Error **errp)
+{
+ switch (action) {
+ case PANIC_ACTION_NONE:
+ pause_on_panic = 0;
+ break;
+ case PANIC_ACTION_PAUSE:
+ pause_on_panic = 1;
+ break;
+ default:
+ g_assert_not_reached();
+ }
+}
+
+/*
* Process an event|action pair and set the appropriate internal
* state if event and action are valid.
*/
@@ -81,6 +99,10 @@ static int set_runstate_action(void *opaque, const char
*event,
act_idx = qapi_enum_parse(&ShutdownAction_lookup, action, -1, errp);
shutdown_set_action(act_idx, NULL);
break;
+ case RUN_STATE_EVENT_TYPE_PANIC:
+ act_idx = qapi_enum_parse(&PanicAction_lookup, action, -1, errp);
+ panic_set_action(act_idx, NULL);
+ break;
case RUN_STATE_EVENT_TYPE_WATCHDOG:
if (select_watchdog_action(action) == -1) {
error_report("invalid parameter value: %s", action);
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 2b1583e..20f89cb 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -150,6 +150,7 @@ int singlestep = 0;
int fd_bootchk = 1;
int no_reboot;
int no_shutdown = 0;
+int pause_on_panic = 1;
int graphic_rotate = 0;
const char *watchdog;
QEMUOptionRom option_rom[MAX_OPTION_ROMS];
@@ -1449,9 +1450,16 @@ void qemu_system_guest_panicked(GuestPanicInformation
*info)
if (current_cpu) {
current_cpu->crash_occurred = true;
}
- qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE,
- !!info, info);
- vm_stop(RUN_STATE_GUEST_PANICKED);
+
+ if (pause_on_panic) {
+ qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE,
+ !!info, info);
+ vm_stop(RUN_STATE_GUEST_PANICKED);
+ } else {
+ qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_RUN,
+ !!info, info);
+ }
+
if (!no_shutdown) {
qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_POWEROFF,
!!info, info);
--
1.8.3.1