xen-console: add save/restore
Add code to:
1. Deal with the console page being canonicalized. During save, the
console's mfn in the start_info structure is canonicalized to a pfn.
In order to deal with that, we always use a copy of the pfn and
indirect off that all the time. However, we fall back to using the
mfn if the pfn hasn't been initialized yet.
2. Restore the console event channel, and rebind it to the existing irq.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c
index d5fe0a8..db2ae42 100644
--- a/drivers/char/hvc_xen.c
+++ b/drivers/char/hvc_xen.c
@@ -39,9 +39,14 @@
/* ------------------------------------------------------------------ */
+static unsigned long console_pfn = ~0ul;
+
static inline struct xencons_interface *xencons_interface(void)
{
- return mfn_to_virt(xen_start_info->console.domU.mfn);
+ if (console_pfn == ~0ul)
+ return mfn_to_virt(xen_start_info->console.domU.mfn);
+ else
+ return __va(console_pfn << PAGE_SHIFT);
}
static inline void notify_daemon(void)
@@ -101,20 +106,32 @@
{
struct hvc_struct *hp;
- if (!is_running_on_xen())
- return 0;
+ if (!is_running_on_xen() ||
+ is_initial_xendomain() ||
+ !xen_start_info->console.domU.evtchn)
+ return -ENODEV;
xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
if (xencons_irq < 0)
- xencons_irq = 0 /* NO_IRQ */;
+ xencons_irq = 0; /* NO_IRQ */
+
hp = hvc_alloc(HVC_COOKIE, xencons_irq, &hvc_ops, 256);
if (IS_ERR(hp))
return PTR_ERR(hp);
hvc = hp;
+
+ console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn);
+
return 0;
}
+void xen_console_resume(void)
+{
+ if (xencons_irq)
+ rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq);
+}
+
static void __exit xen_fini(void)
{
if (hvc)