| Message ID | 20180102170936.6150-2-danielhb@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/02/2018 11:09 AM, Daniel Henrique Barboza wrote: > 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 > ... > > 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). > > Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> > --- Only an interface review: > arch_init.c | 1 + > include/sysemu/sysemu.h | 1 + > qapi-schema.json | 3 ++- > vl.c | 5 +++++ > 4 files changed, 9 insertions(+), 1 deletion(-) > > +++ b/qapi-schema.json > @@ -2388,11 +2388,12 @@ > # Information describing the QEMU target. > # > # @arch: the target architecture (eg "x86_64", "i386", etc) > +# @wakeup-suspend-support: true if the target supports wake up from suspend Missing a '(since 2.12)' notation. > # > # Since: 1.2.0 > ## > { 'struct': 'TargetInfo', > - 'data': { 'arch': 'str' } } > + 'data': { 'arch': 'str', 'wakeup-suspend-support': 'bool' } } The struct is output-only, so adding the new field unconditionally is backwards-compatible.
On 01/02/2018 06:06 PM, Eric Blake wrote: > On 01/02/2018 11:09 AM, Daniel Henrique Barboza wrote: >> 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 >> > ... >> 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). >> >> Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> >> --- > Only an interface review: > >> arch_init.c | 1 + >> include/sysemu/sysemu.h | 1 + >> qapi-schema.json | 3 ++- >> vl.c | 5 +++++ >> 4 files changed, 9 insertions(+), 1 deletion(-) >> >> +++ b/qapi-schema.json >> @@ -2388,11 +2388,12 @@ >> # Information describing the QEMU target. >> # >> # @arch: the target architecture (eg "x86_64", "i386", etc) >> +# @wakeup-suspend-support: true if the target supports wake up from suspend > Missing a '(since 2.12)' notation. TargetInfo is marked as "Since 1.2.0". Should I add the 2.12.0 notation to the new parameter or change the 1.2.0 notation of TargetInfo? > >> # >> # Since: 1.2.0 >> ## >> { 'struct': 'TargetInfo', >> - 'data': { 'arch': 'str' } } >> + 'data': { 'arch': 'str', 'wakeup-suspend-support': 'bool' } } > The struct is output-only, so adding the new field unconditionally is > backwards-compatible. > I believe it's worth adding this info in the commit message. Thanks, Daniel
On 01/02/2018 02:28 PM, Daniel Henrique Barboza wrote: >>> 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). >>> >>> Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> >>> --- >> Only an interface review: >> >>> @@ -2388,11 +2388,12 @@ >>> # Information describing the QEMU target. >>> # >>> # @arch: the target architecture (eg "x86_64", "i386", etc) >>> +# @wakeup-suspend-support: true if the target supports wake up from >>> suspend >> Missing a '(since 2.12)' notation. > > TargetInfo is marked as "Since 1.2.0". Should I add the 2.12.0 notation > to the > new parameter or change the 1.2.0 notation of TargetInfo? Just on the new field, as in: ## # @TargetInfo: # # Information describing the QEMU target. # # @arch: the target architecture (eg "x86_64", "i386", etc) # @wakeup-suspend-support: true if the target supports wake up from # suspend (since 2.12) # # Since: 1.2.0 ##
diff --git a/arch_init.c b/arch_init.c index a0b8ed6167..9c5c519d9d 100644 --- a/arch_init.c +++ b/arch_init.c @@ -109,6 +109,7 @@ TargetInfo *qmp_query_target(Error **errp) TargetInfo *info = g_malloc0(sizeof(*info)); info->arch = g_strdup(TARGET_NAME); + info->wakeup_suspend_support = !qemu_wakeup_notifier_is_empty(); return info; } diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h index 31612caf10..b15374e0b8 100644 --- a/include/sysemu/sysemu.h +++ b/include/sysemu/sysemu.h @@ -69,6 +69,7 @@ typedef enum WakeupReason { void qemu_system_reset_request(ShutdownCause reason); void qemu_system_suspend_request(void); void qemu_register_suspend_notifier(Notifier *notifier); +bool qemu_wakeup_notifier_is_empty(void); void qemu_system_wakeup_request(WakeupReason reason); void qemu_system_wakeup_enable(WakeupReason reason, bool enabled); void qemu_register_wakeup_notifier(Notifier *notifier); diff --git a/qapi-schema.json b/qapi-schema.json index 5c06745c79..6ed741d00b 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -2388,11 +2388,12 @@ # Information describing the QEMU target. # # @arch: the target architecture (eg "x86_64", "i386", etc) +# @wakeup-suspend-support: true if the target supports wake up from suspend # # Since: 1.2.0 ## { 'struct': 'TargetInfo', - 'data': { 'arch': 'str' } } + 'data': { 'arch': 'str', 'wakeup-suspend-support': 'bool' } } ## # @query-target: diff --git a/vl.c b/vl.c index d3a5c5d021..871c1f9bd1 100644 --- a/vl.c +++ b/vl.c @@ -1844,6 +1844,11 @@ void qemu_register_wakeup_notifier(Notifier *notifier) notifier_list_add(&wakeup_notifiers, notifier); } +bool qemu_wakeup_notifier_is_empty(void) +{ + return QLIST_EMPTY(&wakeup_notifiers.notifiers); +} + void qemu_system_killed(int signal, pid_t pid) { shutdown_signal = signal;
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 there are only two subscribers of the wake up event: one in hw/acpi/core.c and another one in hw/i386/xen/xen-hvm.c. This means that system_wakeup does not work as intended with other architectures. 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 adds a new flag called 'wakeup-suspend-support' in TargetInfo that allows the caller to query if the guest supports wake up from suspend via system_wakeup. It goes over the subscribers of the wake up event and, if it's empty, it assumes that the guest does not support wake up from suspend (and thus, pm-suspend itself). This is the expected output of query-target when running a x86 guest: {"execute" : "query-target"} {"return": {"arch": "x86_64", "wakeup-suspend-support": true}} This is the output when running a pseries guest: {"execute" : "query-target"} {"return": {"arch": "ppc64", "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). Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> --- arch_init.c | 1 + include/sysemu/sysemu.h | 1 + qapi-schema.json | 3 ++- vl.c | 5 +++++ 4 files changed, 9 insertions(+), 1 deletion(-)