From 0e91398f2a5d4eb6b07df8115917d0d1cf3e9b58 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 26 May 2008 23:31:27 +0100 Subject: xen: implement save/restore This patch implements Xen save/restore and migration. Saving is triggered via xenbus, which is polled in drivers/xen/manage.c. When a suspend request comes in, the kernel prepares itself for saving by: 1 - Freeze all processes. This is primarily to prevent any partially-completed pagetable updates from confusing the suspend process. If CONFIG_PREEMPT isn't defined, then this isn't necessary. 2 - Suspend xenbus and other devices 3 - Stop_machine, to make sure all the other vcpus are quiescent. The Xen tools require the domain to run its save off vcpu0. 4 - Within the stop_machine state, it pins any unpinned pgds (under construction or destruction), performs canonicalizes various other pieces of state (mostly converting mfns to pfns), and finally 5 - Suspend the domain Restore reverses the steps used to save the domain, ending when all the frozen processes are thawed. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner --- include/xen/xen-ops.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/xen/xen-ops.h') diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index 10ddfe0142d0..5d7a6db54a8c 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -5,4 +5,13 @@ DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu); +void xen_pre_suspend(void); +void xen_post_suspend(int suspend_cancelled); + +void xen_mm_pin_all(void); +void xen_mm_unpin_all(void); + +void xen_time_suspend(void); +void xen_time_resume(void); + #endif /* INCLUDE_XEN_OPS_H */ -- cgit v1.2.3 From 359cdd3f866b6219a6729e313faf2221397f3278 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 26 May 2008 23:31:28 +0100 Subject: xen: maintain clock offset over save/restore Hook into the device model to make sure that timekeeping's resume handler is called. This deals with our clocksource's non-monotonicity over the save/restore. Explicitly call clock_has_changed() to make sure that all the timers get retriggered properly. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner --- arch/x86/xen/time.c | 8 -------- drivers/xen/manage.c | 15 ++++++++++++--- include/xen/xen-ops.h | 3 --- 3 files changed, 12 insertions(+), 14 deletions(-) (limited to 'include/xen/xen-ops.h') diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 0bef256e5f2d..c39e1a5aa241 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -572,14 +572,6 @@ void xen_setup_cpu_clockevents(void) clockevents_register_device(&__get_cpu_var(xen_clock_events)); } -void xen_time_suspend(void) -{ -} - -void xen_time_resume(void) -{ -} - __init void xen_time_init(void) { int cpu = smp_processor_id(); diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index ba85fa2cff33..675c3dd23962 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -34,14 +34,21 @@ static enum shutdown_state shutting_down = SHUTDOWN_INVALID; static int xen_suspend(void *data) { int *cancelled = data; + int err; BUG_ON(!irqs_disabled()); load_cr3(swapper_pg_dir); + err = device_power_down(PMSG_SUSPEND); + if (err) { + printk(KERN_ERR "xen_suspend: device_power_down failed: %d\n", + err); + return err; + } + xen_mm_pin_all(); gnttab_suspend(); - xen_time_suspend(); xen_pre_suspend(); /* @@ -52,10 +59,11 @@ static int xen_suspend(void *data) *cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info)); xen_post_suspend(*cancelled); - xen_time_resume(); gnttab_resume(); xen_mm_unpin_all(); + device_power_up(); + if (!*cancelled) { xen_irq_resume(); xen_console_resume(); @@ -105,7 +113,8 @@ static void do_suspend(void) device_resume(); - + /* Make sure timer events get retriggered on all CPUs */ + clock_was_set(); out: #ifdef CONFIG_PREEMPT thaw_processes(); diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index 5d7a6db54a8c..a706d6a78960 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -11,7 +11,4 @@ void xen_post_suspend(int suspend_cancelled); void xen_mm_pin_all(void); void xen_mm_unpin_all(void); -void xen_time_suspend(void); -void xen_time_resume(void); - #endif /* INCLUDE_XEN_OPS_H */ -- cgit v1.2.3