From c753e8e72548493d2a110c0482c4a987a733b033 Mon Sep 17 00:00:00 2001 From: Alejandro Jimenez Date: Fri, 11 Dec 2020 17:31:52 -0500 Subject: vl: Add option to avoid stopping VM upon guest panic 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 Signed-off-by: Alejandro Jimenez Message-Id: <1607705564-26264-3-git-send-email-alejandro.j.jimenez@oracle.com> [Do not fix panic action in the variable, instead modify -no-shutdown. - Paolo] Signed-off-by: Paolo Bonzini --- softmmu/runstate-action.c | 5 +++++ softmmu/runstate.c | 18 ++++++++++++++---- softmmu/vl.c | 5 ++++- 3 files changed, 23 insertions(+), 5 deletions(-) (limited to 'softmmu') diff --git a/softmmu/runstate-action.c b/softmmu/runstate-action.c index 44de01a..99ce880 100644 --- a/softmmu/runstate-action.c +++ b/softmmu/runstate-action.c @@ -15,6 +15,7 @@ RebootAction reboot_action = REBOOT_ACTION_NONE; ShutdownAction shutdown_action = SHUTDOWN_ACTION_POWEROFF; +PanicAction panic_action = PANIC_ACTION_POWEROFF; /* * Receives actions to be applied for specific guest events @@ -30,6 +31,10 @@ void qmp_set_action(bool has_reboot, RebootAction reboot, reboot_action = reboot; } + if (has_panic) { + panic_action = panic; + } + if (has_watchdog) { qmp_watchdog_set_action(watchdog, errp); } diff --git a/softmmu/runstate.c b/softmmu/runstate.c index bd0522e..636aab0 100644 --- a/softmmu/runstate.c +++ b/softmmu/runstate.c @@ -469,13 +469,23 @@ 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 (shutdown_action == SHUTDOWN_ACTION_POWEROFF) { + /* + * TODO: Currently the available panic actions are: none, pause, and + * poweroff, but in principle debug and reset could be supported as well. + * Investigate any potential use cases for the unimplemented actions. + */ + if (panic_action == PANIC_ACTION_PAUSE) { + qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE, + !!info, info); + vm_stop(RUN_STATE_GUEST_PANICKED); + } else if (panic_action == PANIC_ACTION_POWEROFF) { qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_POWEROFF, !!info, info); + vm_stop(RUN_STATE_GUEST_PANICKED); qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_PANIC); + } else { + qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_RUN, + !!info, info); } if (info) { diff --git a/softmmu/vl.c b/softmmu/vl.c index 6d1a7eb..3921a04 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -490,6 +490,9 @@ static QemuOptsList qemu_action_opts = { .name = "reboot", .type = QEMU_OPT_STRING, },{ + .name = "panic", + .type = QEMU_OPT_STRING, + },{ .name = "watchdog", .type = QEMU_OPT_STRING, }, @@ -3212,7 +3215,7 @@ void qemu_init(int argc, char **argv, char **envp) break; case QEMU_OPTION_no_shutdown: olist = qemu_find_opts("action"); - qemu_opts_parse_noisily(olist, "shutdown=pause", false); + qemu_opts_parse_noisily(olist, "panic=pause,shutdown=pause", false); break; case QEMU_OPTION_show_cursor: warn_report("The -show-cursor option is deprecated. Please " -- cgit v1.1