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>

6 files changed, 90 insertions, 11 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index b211a04c4b2c..127c95c8d15e 100644
--- a/arch/x86/xen/enlighten.c
+++ b/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;
diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c
index a9c661108034..d07479c340f5 100644
--- a/arch/x86/xen/suspend.c
+++ b/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();
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 0d0e0e6a7479..01c9dd386522 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/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);
 
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index af9c5594d315..1799bd890315 100644
--- a/drivers/xen/manage.c
+++ b/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);
diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index a0ee5d06f715..bdb44f2473e8 100644
--- a/drivers/xen/platform-pci.c
+++ b/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)
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index 883a21bba24b..46bc81ef74c6 100644
--- a/include/xen/xen-ops.h
+++ b/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 */