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>
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index a1bc89a..a0503ac 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -9,6 +9,7 @@
extern const char xen_hypervisor_callback[];
extern const char xen_failsafe_callback[];
+struct trap_info;
void xen_copy_trap_info(struct trap_info *traps);
DECLARE_PER_CPU(unsigned long, xen_cr3);
@@ -19,6 +20,7 @@
extern struct shared_info *HYPERVISOR_shared_info;
void xen_setup_mfn_list_list(void);
+void xen_setup_shared_info(void);
char * __init xen_memory_setup(void);
void __init xen_arch_setup(void);
@@ -59,6 +61,8 @@
int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *),
void *info, int wait);
+extern cpumask_t xen_cpu_initialized_map;
+
/* Declare an asm function, along with symbols needed to make it
inlineable */