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authorJeremy Fitzhardinge <jeremy@goop.org>2008-05-26 23:31:27 +0100
committerThomas Gleixner <tglx@linutronix.de>2008-05-27 10:11:38 +0200
commit0e91398f2a5d4eb6b07df8115917d0d1cf3e9b58 (patch)
treec6a3b31b7bcbbfb55bb2304d8651abdd28cdad54 /drivers/xen/events.c
parent7d88d32a4670af583c896e5ecd3929b78538ca62 (diff)
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 <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers/xen/events.c')
-rw-r--r--drivers/xen/events.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 70375a690761..73d78dc9b875 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -674,6 +674,89 @@ static int retrigger_dynirq(unsigned int irq)
return ret;
}
+static void restore_cpu_virqs(unsigned int cpu)
+{
+ struct evtchn_bind_virq bind_virq;
+ int virq, irq, evtchn;
+
+ for (virq = 0; virq < NR_VIRQS; virq++) {
+ if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
+ continue;
+
+ BUG_ON(irq_info[irq].type != IRQT_VIRQ);
+ BUG_ON(irq_info[irq].index != virq);
+
+ /* Get a new binding from Xen. */
+ bind_virq.virq = virq;
+ bind_virq.vcpu = cpu;
+ if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
+ &bind_virq) != 0)
+ BUG();
+ evtchn = bind_virq.port;
+
+ /* Record the new mapping. */
+ evtchn_to_irq[evtchn] = irq;
+ irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
+ bind_evtchn_to_cpu(evtchn, cpu);
+
+ /* Ready for use. */
+ unmask_evtchn(evtchn);
+ }
+}
+
+static void restore_cpu_ipis(unsigned int cpu)
+{
+ struct evtchn_bind_ipi bind_ipi;
+ int ipi, irq, evtchn;
+
+ for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
+ if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
+ continue;
+
+ BUG_ON(irq_info[irq].type != IRQT_IPI);
+ BUG_ON(irq_info[irq].index != ipi);
+
+ /* Get a new binding from Xen. */
+ bind_ipi.vcpu = cpu;
+ if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
+ &bind_ipi) != 0)
+ BUG();
+ evtchn = bind_ipi.port;
+
+ /* Record the new mapping. */
+ evtchn_to_irq[evtchn] = irq;
+ irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
+ bind_evtchn_to_cpu(evtchn, cpu);
+
+ /* Ready for use. */
+ unmask_evtchn(evtchn);
+
+ }
+}
+
+void xen_irq_resume(void)
+{
+ unsigned int cpu, irq, evtchn;
+
+ init_evtchn_cpu_bindings();
+
+ /* New event-channel space is not 'live' yet. */
+ for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
+ mask_evtchn(evtchn);
+
+ /* No IRQ <-> event-channel mappings. */
+ for (irq = 0; irq < NR_IRQS; irq++)
+ irq_info[irq].evtchn = 0; /* zap event-channel binding */
+
+ for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
+ evtchn_to_irq[evtchn] = -1;
+
+ for_each_possible_cpu(cpu) {
+ restore_cpu_virqs(cpu);
+ restore_cpu_ipis(cpu);
+ }
+}
+
static struct irq_chip xen_dynamic_chip __read_mostly = {
.name = "xen-dyn",
.mask = disable_dynirq,