xen: Suspend ticks on all CPUs during suspend (2b953a5e) · Commits · 戴 / test

Commit ("clockevents: Manage device's state separately for the core") decouples clockevent device's modes from states. With this change when a Xen guest tries to resume, it won't be calling its set_mode op which needs to be done on each VCPU in order to make the hypervisor aware that we are in oneshot mode. This happens because clockevents_tick_resume() (which is an intermediate step of resuming ticks on a processor) doesn't call clockevents_set_state() anymore and because during suspend clockevent devices on all VCPUs (except for the one doing the suspend) are left in ONESHOT state. As result, during resume the clockevents state machine will assume that device is already where it should be and doesn't need to be updated. To avoid this problem we should suspend ticks on all VCPUs during suspend. Signed-off-by:

Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by:

David Vrabel <david.vrabel@citrix.com>

arch/x86/xen/suspend.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -88,7 +88,17 @@ static void xen_vcpu_notify_restore(void *data)
		tick_resume_local();
		}

		static void xen_vcpu_notify_suspend(void *data)
		{
		tick_suspend_local();
		}

		void xen_arch_resume(void)
		{
		on_each_cpu(xen_vcpu_notify_restore, NULL, 1);
		}

		void xen_arch_suspend(void)
		{
		on_each_cpu(xen_vcpu_notify_suspend, NULL, 1);
		}

drivers/xen/manage.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -131,6 +131,8 @@ static void do_suspend(void)
		goto out_resume;
		}

		xen_arch_suspend();

		si.cancelled = 1;

		err = stop_machine(xen_suspend, &si, cpumask_of(0));
		@@ -148,11 +150,12 @@ static void do_suspend(void)
		si.cancelled = 1;
		}

		out_resume:
		if (!si.cancelled) {
		xen_arch_resume();

		out_resume:
		if (!si.cancelled)
		xs_resume();
		} else
		else
		xs_suspend_cancel();

		dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE);

include/xen/xen-ops.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -13,6 +13,7 @@ void xen_arch_post_suspend(int suspend_cancelled);

		void xen_timer_resume(void);
		void xen_arch_resume(void);
		void xen_arch_suspend(void);

		void xen_resume_notifier_register(struct notifier_block *nb);
		void xen_resume_notifier_unregister(struct notifier_block *nb);

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