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/52148f88.5000...@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 <pbonz...@redhat.com> Signed-off-by: Alejandro Jimenez <alejandro.j.jime...@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