xen: Fix x86 sched_clock() interface for xen (867cefb4) · Commits · 戴 / test

Commit ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface") broke Xen guest time handling across migration: [ 187.249951] Freezing user space processes ... (elapsed 0.001 seconds) done. [ 187.251137] OOM killer disabled. [ 187.251137] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 187.252299] suspending xenstore... [ 187.266987] xen:grant_table: Grant tables using version 1 layout [18446743811.706476] OOM killer enabled. [18446743811.706478] Restarting tasks ... done. [18446743811.720505] Setting capacity to 16777216 Fix that by setting xen_sched_clock_offset at resume time to ensure a monotonic clock value. [boris: replaced pr_info() with pr_info_once() in xen_callback_vector() to avoid printing with incorrect timestamp during resume (as we haven't re-adjusted the clock yet)] Fixes: ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface") Cc: <stable@vger.kernel.org> # 4.11 Reported-by:

Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by:

Juergen Gross <jgross@suse.com> Tested-by:

Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by:

Boris Ostrovsky <boris.ostrovsky@oracle.com>

arch/x86/xen/time.c

+9 −3

Original line number	Diff line number	Diff line
		@@ -361,8 +361,6 @@ void xen_timer_resume(void)
		{
		int cpu;

		pvclock_resume();

		if (xen_clockevent != &xen_vcpuop_clockevent)
		return;

		@@ -379,12 +377,15 @@ static const struct pv_time_ops xen_time_ops __initconst = {
		};

		static struct pvclock_vsyscall_time_info *xen_clock __read_mostly;
		static u64 xen_clock_value_saved;

		void xen_save_time_memory_area(void)
		{
		struct vcpu_register_time_memory_area t;
		int ret;

		xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset;

		if (!xen_clock)
		return;

		@@ -404,7 +405,7 @@ void xen_restore_time_memory_area(void)
		int ret;

		if (!xen_clock)
		return;
		goto out;

		t.addr.v = &xen_clock->pvti;

		@@ -421,6 +422,11 @@ void xen_restore_time_memory_area(void)
		if (ret != 0)
		pr_notice("Cannot restore secondary vcpu_time_info (err %d)",
		ret);

		out:
		/* Need pvclock_resume() before using xen_clocksource_read(). */
		pvclock_resume();
		xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved;
		}

		static void xen_setup_vsyscall_time_info(void)

drivers/xen/events/events_base.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1650,7 +1650,7 @@ void xen_callback_vector(void)
		xen_have_vector_callback = 0;
		return;
		}
		pr_info("Xen HVM callback vector for event delivery is enabled\n");
		pr_info_once("Xen HVM callback vector for event delivery is enabled\n");
		alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
		xen_hvm_callback_vector);
		}

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