xen: Add suspend/resume support for PV on HVM guests.

Suspend/resume requires few different things on HVM: the suspend
hypercall is different; we don't need to save/restore memory related
settings; except the shared info page and the callback mechanism.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

arch/x86/xen/enlighten.c

@@ -1262,13 +1262,15 @@ static int init_hvm_pv_info(int *major, int *minor)
 	return 0;
 }
 
-static void __init init_shared_info(void)
+void xen_hvm_init_shared_info(void)
 {
+	int cpu;
 	struct xen_add_to_physmap xatp;
-	struct shared_info *shared_info_page;
+	static struct shared_info *shared_info_page = 0;
 
-	shared_info_page = (struct shared_info *)
-		extend_brk(PAGE_SIZE, PAGE_SIZE);
+	if (!shared_info_page)
+		shared_info_page = (struct shared_info *)
+			extend_brk(PAGE_SIZE, PAGE_SIZE);
 	xatp.domid = DOMID_SELF;
 	xatp.idx = 0;
 	xatp.space = XENMAPSPACE_shared_info;
@@ -1278,7 +1280,17 @@ static void __init init_shared_info(void)
 
 	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 
-	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
+	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
+	 * page, we use it in the event channel upcall and in some pvclock
+	 * related functions. We don't need the vcpu_info placement
+	 * optimizations because we don't use any pv_mmu or pv_irq op on
+	 * HVM.
+	 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
+	 * online but xen_hvm_init_shared_info is run at resume time too and
+	 * in that case multiple vcpus might be online. */
+	for_each_online_cpu(cpu) {
+		per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+	}
 }
 
 static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
@@ -1308,7 +1320,7 @@ static void __init xen_hvm_guest_init(void)
 	if (r < 0)
 		return;
 
-	init_shared_info();
+	xen_hvm_init_shared_info();
 
 	if (xen_feature(XENFEAT_hvm_callback_vector))
 		xen_have_vector_callback = 1;

arch/x86/xen/suspend.c

@@ -26,6 +26,12 @@ void xen_pre_suspend(void)
 		BUG();
 }
 
+void xen_hvm_post_suspend(int suspend_cancelled)
+{
+	xen_hvm_init_shared_info();
+	xen_callback_vector();
+}
+
 void xen_post_suspend(int suspend_cancelled)
 {
 	xen_build_mfn_list_list();

arch/x86/xen/xen-ops.h

@@ -39,6 +39,7 @@ void xen_enable_syscall(void);
 void xen_vcpu_restore(void);
 
 void xen_callback_vector(void);
+void xen_hvm_init_shared_info(void);
 
 void __init xen_build_dynamic_phys_to_machine(void);
 

drivers/xen/manage.c

@@ -9,6 +9,7 @@
 #include <linux/stop_machine.h>
 #include <linux/freezer.h>
 
+#include <xen/xen.h>
 #include <xen/xenbus.h>
 #include <xen/grant_table.h>
 #include <xen/events.h>
@@ -17,6 +18,7 @@
 
 #include <asm/xen/hypercall.h>
 #include <asm/xen/page.h>
+#include <asm/xen/hypervisor.h>
 
 enum shutdown_state {
 	SHUTDOWN_INVALID = -1,
@@ -33,10 +35,30 @@ enum shutdown_state {
 static enum shutdown_state shutting_down = SHUTDOWN_INVALID;
 
 #ifdef CONFIG_PM_SLEEP
-static int xen_suspend(void *data)
+static int xen_hvm_suspend(void *data)
 {
+	struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
 	int *cancelled = data;
+
+	BUG_ON(!irqs_disabled());
+
+	*cancelled = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
+
+	xen_hvm_post_suspend(*cancelled);
+	gnttab_resume();
+
+	if (!*cancelled) {
+		xen_irq_resume();
+		xen_timer_resume();
+	}
+
+	return 0;
+}
+
+static int xen_suspend(void *data)
+{
 	int err;
+	int *cancelled = data;
 
 	BUG_ON(!irqs_disabled());
 
@@ -106,7 +128,10 @@ static void do_suspend(void)
 		goto out_resume;
 	}
 
-	err = stop_machine(xen_suspend, &cancelled, cpumask_of(0));
+	if (xen_hvm_domain())
+		err = stop_machine(xen_hvm_suspend, &cancelled, cpumask_of(0));
+	else
+		err = stop_machine(xen_suspend, &cancelled, cpumask_of(0));
 
 	dpm_resume_noirq(PMSG_RESUME);
 
@@ -255,7 +280,19 @@ static int shutdown_event(struct notifier_block *notifier,
 	return NOTIFY_DONE;
 }
 
-static int __init setup_shutdown_event(void)
+static int __init __setup_shutdown_event(void)
+{
+	/* Delay initialization in the PV on HVM case */
+	if (xen_hvm_domain())
+		return 0;
+
+	if (!xen_pv_domain())
+		return -ENODEV;
+
+	return xen_setup_shutdown_event();
+}
+
+int xen_setup_shutdown_event(void)
 {
 	static struct notifier_block xenstore_notifier = {
 		.notifier_call = shutdown_event
@@ -266,4 +303,4 @@ static int __init setup_shutdown_event(void)
 }
 EXPORT_SYMBOL_GPL(xen_setup_shutdown_event);
 
-subsys_initcall(setup_shutdown_event);
+subsys_initcall(__setup_shutdown_event);

drivers/xen/platform-pci.c

@@ -31,6 +31,7 @@
 #include <xen/xenbus.h>
 #include <xen/events.h>
 #include <xen/hvm.h>
+#include <xen/xen-ops.h>
 
 #define DRV_NAME    "xen-platform-pci"
 
@@ -41,6 +42,7 @@ MODULE_LICENSE("GPL");
 static unsigned long platform_mmio;
 static unsigned long platform_mmio_alloc;
 static unsigned long platform_mmiolen;
+static uint64_t callback_via;
 
 unsigned long alloc_xen_mmio(unsigned long len)
 {
@@ -85,13 +87,25 @@ static int xen_allocate_irq(struct pci_dev *pdev)
 			"xen-platform-pci", pdev);
 }
 
+static int platform_pci_resume(struct pci_dev *pdev)
+{
+	int err;
+	if (xen_have_vector_callback)
+		return 0;
+	err = xen_set_callback_via(callback_via);
+	if (err) {
+		dev_err(&pdev->dev, "platform_pci_resume failure!\n");
+		return err;
+	}
+	return 0;
+}
+
 static int __devinit platform_pci_init(struct pci_dev *pdev,
 				       const struct pci_device_id *ent)
 {
 	int i, ret;
 	long ioaddr, iolen;
 	long mmio_addr, mmio_len;
-	uint64_t callback_via;
 	unsigned int max_nr_gframes;
 
 	i = pci_enable_device(pdev);
@@ -148,6 +162,9 @@ static int __devinit platform_pci_init(struct pci_dev *pdev,
 	if (ret)
 		goto out;
 	xenbus_probe(NULL);
+	ret = xen_setup_shutdown_event();
+	if (ret)
+		goto out;
 	return 0;
 
 out:
@@ -171,6 +188,9 @@ static struct pci_driver platform_driver = {
 	.name =           DRV_NAME,
 	.probe =          platform_pci_init,
 	.id_table =       platform_pci_tbl,
+#ifdef CONFIG_PM
+	.resume_early =   platform_pci_resume,
+#endif
 };
 
 static int __init platform_pci_module_init(void)

include/xen/xen-ops.h

@@ -7,6 +7,7 @@ DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu);
 
 void xen_pre_suspend(void);
 void xen_post_suspend(int suspend_cancelled);
+void xen_hvm_post_suspend(int suspend_cancelled);
 
 void xen_mm_pin_all(void);
 void xen_mm_unpin_all(void);
@@ -14,4 +15,6 @@ void xen_mm_unpin_all(void);
 void xen_timer_resume(void);
 void xen_arch_resume(void);
 
+int xen_setup_shutdown_event(void);
+
 #endif /* INCLUDE_XEN_OPS_H */