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 --- arch/x86/xen/suspend.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 arch/x86/xen/suspend.c (limited to 'arch/x86/xen/suspend.c') diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c new file mode 100644 index 000000000000..7620a16fe535 --- /dev/null +++ b/arch/x86/xen/suspend.c @@ -0,0 +1,42 @@ +#include + +#include +#include +#include + +#include +#include + +#include "xen-ops.h" +#include "mmu.h" + +void xen_pre_suspend(void) +{ + xen_start_info->store_mfn = mfn_to_pfn(xen_start_info->store_mfn); + xen_start_info->console.domU.mfn = + mfn_to_pfn(xen_start_info->console.domU.mfn); + + BUG_ON(!irqs_disabled()); + + HYPERVISOR_shared_info = &xen_dummy_shared_info; + if (HYPERVISOR_update_va_mapping(fix_to_virt(FIX_PARAVIRT_BOOTMAP), + __pte_ma(0), 0)) + BUG(); +} + +void xen_post_suspend(int suspend_cancelled) +{ + if (suspend_cancelled) { + xen_start_info->store_mfn = + pfn_to_mfn(xen_start_info->store_mfn); + xen_start_info->console.domU.mfn = + pfn_to_mfn(xen_start_info->console.domU.mfn); + } else { +#ifdef CONFIG_SMP + xen_cpu_initialized_map = cpu_online_map; +#endif + } + + xen_setup_shared_info(); +} + -- cgit v1.2.3 From 9c7a794209f8a91f47697c3be20597eb60531e6d Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Sat, 31 May 2008 01:33:02 +0100 Subject: xen: restore vcpu_info mapping If we're using vcpu_info mapping, then make sure its restored on all processors before relasing them from stop_machine. The only complication is that if this fails, we can't continue because we've already made assumptions that the mapping is available (baked in calls to the _direct versions of the functions, for example). Fortunately this can only happen with a 32-bit hypervisor, which may possibly run out of mapping space. On a 64-bit hypervisor, this is a non-issue. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar --- arch/x86/xen/enlighten.c | 30 +++++++++++++++++++++++++++++- arch/x86/xen/suspend.c | 4 +++- arch/x86/xen/xen-ops.h | 1 + 3 files changed, 33 insertions(+), 2 deletions(-) (limited to 'arch/x86/xen/suspend.c') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index ed9f04b3836d..8e6152e6ed88 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -98,7 +98,7 @@ struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info; */ static int have_vcpu_info_placement = 1; -static void __init xen_vcpu_setup(int cpu) +static void xen_vcpu_setup(int cpu) { struct vcpu_register_vcpu_info info; int err; @@ -136,6 +136,34 @@ static void __init xen_vcpu_setup(int cpu) } } +/* + * On restore, set the vcpu placement up again. + * If it fails, then we're in a bad state, since + * we can't back out from using it... + */ +void xen_vcpu_restore(void) +{ + if (have_vcpu_info_placement) { + int cpu; + + for_each_online_cpu(cpu) { + bool other_cpu = (cpu != smp_processor_id()); + + if (other_cpu && + HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL)) + BUG(); + + xen_vcpu_setup(cpu); + + if (other_cpu && + HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL)) + BUG(); + } + + BUG_ON(!have_vcpu_info_placement); + } +} + static void __init xen_banner(void) { printk(KERN_INFO "Booting paravirtualized kernel on %s\n", diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index 7620a16fe535..7ab10f6b39a5 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -26,6 +26,8 @@ void xen_pre_suspend(void) void xen_post_suspend(int suspend_cancelled) { + xen_setup_shared_info(); + if (suspend_cancelled) { xen_start_info->store_mfn = pfn_to_mfn(xen_start_info->store_mfn); @@ -35,8 +37,8 @@ void xen_post_suspend(int suspend_cancelled) #ifdef CONFIG_SMP xen_cpu_initialized_map = cpu_online_map; #endif + xen_vcpu_restore(); } - xen_setup_shared_info(); } diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index a0503acad664..a457e03e1b21 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -26,6 +26,7 @@ char * __init xen_memory_setup(void); void __init xen_arch_setup(void); void __init xen_init_IRQ(void); void xen_enable_sysenter(void); +void xen_vcpu_restore(void); void __init xen_build_dynamic_phys_to_machine(void); -- cgit v1.2.3 From d07af1f0e3a3e378074fc36322dd7b0e72d9a3e2 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Sat, 31 May 2008 01:33:03 +0100 Subject: xen: resume timers on all vcpus On resume, the vcpu timer modes will not be restored. The timer infrastructure doesn't do this for us, since it assumes the cpus are offline. We can just poke the other vcpus into the right mode directly though. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar --- arch/x86/xen/suspend.c | 1 + arch/x86/xen/time.c | 13 +++++++++++++ arch/x86/xen/xen-ops.h | 1 + 3 files changed, 15 insertions(+) (limited to 'arch/x86/xen/suspend.c') diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index 7ab10f6b39a5..251669a932d4 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -38,6 +38,7 @@ void xen_post_suspend(int suspend_cancelled) xen_cpu_initialized_map = cpu_online_map; #endif xen_vcpu_restore(); + xen_timer_resume(); } } diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index c39e1a5aa241..ea137fb660c0 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -572,6 +572,19 @@ void xen_setup_cpu_clockevents(void) clockevents_register_device(&__get_cpu_var(xen_clock_events)); } +void xen_timer_resume(void) +{ + int cpu; + + if (xen_clockevent != &xen_vcpuop_clockevent) + return; + + for_each_online_cpu(cpu) { + if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL)) + BUG(); + } +} + __init void xen_time_init(void) { int cpu = smp_processor_id(); diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index a457e03e1b21..9a055592a307 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -37,6 +37,7 @@ void __init xen_time_init(void); unsigned long xen_get_wallclock(void); int xen_set_wallclock(unsigned long time); unsigned long long xen_sched_clock(void); +void xen_timer_resume(void); irqreturn_t xen_debug_interrupt(int irq, void *dev_id); -- cgit v1.2.3 From ad55db9fed6d6cd09333045945cb03ba2c070085 Mon Sep 17 00:00:00 2001 From: Isaku Yamahata Date: Tue, 8 Jul 2008 15:06:32 -0700 Subject: xen: add xen_arch_resume()/xen_timer_resume hook for ia64 support add xen_timer_resume() hook. Timer resume should be done after event channel is resumed. add xen_arch_resume() hook when ipi becomes usable after resume. After resume, some cpu specific resource must be reinitialized on ia64 that can't be set by another cpu. However available hooks is run once on only one cpu so that ipi has to be used. During stop_machine_run() ipi can't be used because interrupt is masked. So add another hook after stop_machine_run(). Another approach might be use resume hook which is run by device_resume(). However device_resume() may be executed on suspend error recovery path. So it is necessary to determine whether it is executed on real resume path or error recovery path. Signed-off-by: Isaku Yamahata Cc: Stephen Tweedie Cc: Eduardo Habkost Cc: Mark McLoughlin Signed-off-by: Ingo Molnar --- arch/x86/xen/suspend.c | 5 ++++- arch/x86/xen/xen-ops.h | 1 - drivers/xen/manage.c | 6 ++++-- include/xen/xen-ops.h | 3 +++ 4 files changed, 11 insertions(+), 4 deletions(-) (limited to 'arch/x86/xen/suspend.c') diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index 251669a932d4..2a234db5949b 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -38,8 +38,11 @@ void xen_post_suspend(int suspend_cancelled) xen_cpu_initialized_map = cpu_online_map; #endif xen_vcpu_restore(); - xen_timer_resume(); } } +void xen_arch_resume(void) +{ + /* nothing */ +} diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 6f4b1045c1c2..77354d204257 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -37,7 +37,6 @@ void __init xen_time_init(void); unsigned long xen_get_wallclock(void); int xen_set_wallclock(unsigned long time); unsigned long long xen_sched_clock(void); -void xen_timer_resume(void); irqreturn_t xen_debug_interrupt(int irq, void *dev_id); diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 5b546e365f00..2bb268e4ac56 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -68,6 +68,7 @@ static int xen_suspend(void *data) if (!*cancelled) { xen_irq_resume(); xen_console_resume(); + xen_timer_resume(); } return 0; @@ -107,9 +108,10 @@ static void do_suspend(void) goto out; } - if (!cancelled) + if (!cancelled) { + xen_arch_resume(); xenbus_resume(); - else + } else xenbus_suspend_cancel(); device_resume(); diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index a706d6a78960..883a21bba24b 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -11,4 +11,7 @@ void xen_post_suspend(int suspend_cancelled); void xen_mm_pin_all(void); void xen_mm_unpin_all(void); +void xen_timer_resume(void); +void xen_arch_resume(void); + #endif /* INCLUDE_XEN_OPS_H */ -- cgit v1.2.3