From 46ea94ca9cfcd56c27efafd2ff32281360e0267f Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Wed, 5 Dec 2018 17:46:59 -0200 Subject: qmp: query-current-machine with wakeup-suspend-support When issuing the qmp/hmp 'system_wakeup' command, what happens in a nutshell is: - qmp_system_wakeup_request set runstate to RUNNING, sets a wakeup_reason and notify the event - in the main_loop, all vcpus are paused, a system reset is issued, all subscribers of wakeup_notifiers receives a notification, vcpus are then resumed and the wake up QAPI event is fired Note that this procedure alone doesn't ensure that the guest will awake from SUSPENDED state - the subscribers of the wake up event must take action to resume the guest, otherwise the guest will simply reboot. At this moment, only the ACPI machines via acpi_pm1_cnt_init and xen_hvm_init have wake-up from suspend support. However, only the presence of 'system_wakeup' is required for QGA to support 'guest-suspend-ram' and 'guest-suspend-hybrid' at this moment. This means that the user/management will expect to suspend the guest using one of those suspend commands and then resume execution using system_wakeup, regardless of the support offered in system_wakeup in the first place. This patch creates a new API called query-current-machine [1], that holds a new flag called 'wakeup-suspend-support' that indicates if the guest supports wake up from suspend via system_wakeup. The machine is considered to implement wake-up support if a call to a new 'qemu_register_wakeup_support' is made during its init, as it is now being done inside acpi_pm1_cnt_init and xen_hvm_init. This allows for any other machine type to declare wake-up support regardless of ACPI state or wakeup_notifiers subscription, making easier for newer implementations that might have their own mechanisms in the future. This is the expected output of query-current-machine when running a x86 guest: {"execute" : "query-current-machine"} {"return": {"wakeup-suspend-support": true}} Running the same x86 guest, but with the --no-acpi option: {"execute" : "query-current-machine"} {"return": {"wakeup-suspend-support": false}} This is the output when running a pseries guest: {"execute" : "query-current-machine"} {"return": {"wakeup-suspend-support": false}} With this extra tool, management can avoid situations where a guest that does not have proper suspend/wake capabilities ends up in inconsistent state (e.g. https://github.com/open-power-host-os/qemu/issues/31). [1] the decision of creating the query-current-machine API is based on discussions in the QEMU mailing list where it was decided that query-target wasn't a proper place to store the wake-up flag, neither was query-machines because this isn't a static property of the machine object. This new API can then be used to store other dynamic machine properties that are scattered around the code ATM. More info at: https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg04235.html Reported-by: Balamuruhan S Signed-off-by: Daniel Henrique Barboza Message-Id: <20181205194701.17836-2-danielhb413@gmail.com> Reviewed-by: Markus Armbruster Acked-by: Eduardo Habkost Signed-off-by: Markus Armbruster --- hw/acpi/core.c | 6 ++++++ hw/i386/xen/xen-hvm.c | 5 +++++ 2 files changed, 11 insertions(+) (limited to 'hw') diff --git a/hw/acpi/core.c b/hw/acpi/core.c index aafdc61..52e18d7 100644 --- a/hw/acpi/core.c +++ b/hw/acpi/core.c @@ -617,6 +617,12 @@ void acpi_pm1_cnt_init(ACPIREGS *ar, MemoryRegion *parent, ar->pm1.cnt.s4_val = s4_val; ar->wakeup.notify = acpi_notify_wakeup; qemu_register_wakeup_notifier(&ar->wakeup); + + /* + * Register wake-up support in QMP query-current-machine API + */ + qemu_register_wakeup_support(); + memory_region_init_io(&ar->pm1.cnt.io, memory_region_owner(parent), &acpi_pm_cnt_ops, ar, "acpi-cnt", 2); memory_region_add_subregion(parent, 4, &ar->pm1.cnt.io); diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c index 935a367..2143d33 100644 --- a/hw/i386/xen/xen-hvm.c +++ b/hw/i386/xen/xen-hvm.c @@ -1405,6 +1405,11 @@ void xen_hvm_init(PCMachineState *pcms, MemoryRegion **ram_memory) state->wakeup.notify = xen_wakeup_notifier; qemu_register_wakeup_notifier(&state->wakeup); + /* + * Register wake-up support in QMP query-current-machine API + */ + qemu_register_wakeup_support(); + rc = xen_map_ioreq_server(state); if (rc < 0) { goto err; -- cgit v1.1 From fb0641121072d9d612773370688a6887bb78db08 Mon Sep 17 00:00:00 2001 From: Daniel Henrique Barboza Date: Wed, 5 Dec 2018 17:47:01 -0200 Subject: qmp hmp: Make system_wakeup check wake-up support and run state The qmp/hmp command 'system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' from vl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended. This means that system_wakeup is silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it. Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all. All this considered, this patch changes qmp_system_wakeup to check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output of system_wakeup in a guest that does not have wake-up from suspend support (ppc64): (qemu) system_wakeup wake-up from suspend is not supported by this guest (qemu) And this is the output of system_wakeup in a x86 guest that has the support but isn't suspended: (qemu) system_wakeup Unable to wake up: guest is not in suspended state (qemu) Reported-by: Balamuruhan S Signed-off-by: Daniel Henrique Barboza Message-Id: <20181205194701.17836-4-danielhb413@gmail.com> Reviewed-by: Markus Armbruster Acked-by: Eduardo Habkost Reviewed-by: Michael S. Tsirkin Signed-off-by: Markus Armbruster --- hw/acpi/core.c | 3 ++- hw/char/serial.c | 2 +- hw/input/ps2.c | 6 +++--- hw/timer/mc146818rtc.c | 2 +- 4 files changed, 7 insertions(+), 6 deletions(-) (limited to 'hw') diff --git a/hw/acpi/core.c b/hw/acpi/core.c index 52e18d7..d6f0709 100644 --- a/hw/acpi/core.c +++ b/hw/acpi/core.c @@ -514,7 +514,8 @@ static uint32_t acpi_pm_tmr_get(ACPIREGS *ar) static void acpi_pm_tmr_timer(void *opaque) { ACPIREGS *ar = opaque; - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_PMTIMER); + + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_PMTIMER, NULL); ar->tmr.update_sci(ar); } diff --git a/hw/char/serial.c b/hw/char/serial.c index 02463e3..7c42a2a 100644 --- a/hw/char/serial.c +++ b/hw/char/serial.c @@ -611,7 +611,7 @@ static void serial_receive1(void *opaque, const uint8_t *buf, int size) SerialState *s = opaque; if (s->wakeup) { - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL); } if(s->fcr & UART_FCR_FE) { int i; diff --git a/hw/input/ps2.c b/hw/input/ps2.c index eb33ee9..d3161f1 100644 --- a/hw/input/ps2.c +++ b/hw/input/ps2.c @@ -255,7 +255,7 @@ static void ps2_put_keycode(void *opaque, int keycode) PS2KbdState *s = opaque; trace_ps2_put_keycode(opaque, keycode); - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL); if (s->translate) { if (keycode == 0xf0) { @@ -285,7 +285,7 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src, return; } - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL); assert(evt->type == INPUT_EVENT_KIND_KEY); qcode = qemu_input_key_value_to_qcode(key->key); @@ -748,7 +748,7 @@ static void ps2_mouse_sync(DeviceState *dev) } if (s->mouse_buttons) { - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL); } if (!(s->mouse_status & MOUSE_STATUS_REMOTE)) { /* if not remote, send event. Multiple events are sent if diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c index e4e4de8..6948315 100644 --- a/hw/timer/mc146818rtc.c +++ b/hw/timer/mc146818rtc.c @@ -455,7 +455,7 @@ static void rtc_update_timer(void *opaque) if (qemu_clock_get_ns(rtc_clock) >= s->next_alarm_time) { irqs |= REG_C_AF; if (s->cmos_data[RTC_REG_B] & REG_B_AIE) { - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_RTC); + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_RTC, NULL); } } -- cgit v1.1