[PATCH 07/12] Add suspend\resume support for PV on HVM guests.

From: Stefano Stabellini
Date: Tue May 18 2010 - 06:30:46 EST


Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
arch/x86/xen/enlighten.c | 9 ++--
arch/x86/xen/suspend.c | 6 ++
arch/x86/xen/xen-ops.h | 3 +
drivers/xen/manage.c | 95 +++++++++++++++++++++++++++++++++++--
drivers/xen/platform-pci.c | 29 +++++++++++-
drivers/xen/xenbus/xenbus_probe.c | 28 +++++++++++
include/xen/platform_pci.h | 6 ++
include/xen/xen-ops.h | 3 +
8 files changed, 170 insertions(+), 9 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index aac47b0..23b8200 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1268,12 +1268,13 @@ static int init_hvm_pv_info(int *major, int *minor)
return 0;
}

-static void __init init_shared_info(void)
+void init_shared_info(void)
{
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 *) alloc_bootmem_pages(PAGE_SIZE);
+ if (!shared_info_page)
+ shared_info_page = (struct shared_info *) alloc_bootmem_pages(PAGE_SIZE);
xatp.domid = DOMID_SELF;
xatp.idx = 0;
xatp.space = XENMAPSPACE_shared_info;
@@ -1302,7 +1303,7 @@ void do_hvm_pv_evtchn_intr(void)
xen_hvm_evtchn_do_upcall(get_irq_regs());
}

-static void xen_callback_vector(void)
+void xen_callback_vector(void)
{
uint64_t callback_via;
if (xen_feature(XENFEAT_hvm_callback_vector)) {
diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c
index 987267f..86f3b45 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)
+{
+ 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 f9153a3..caf89ee 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -38,6 +38,9 @@ void xen_enable_sysenter(void);
void xen_enable_syscall(void);
void xen_vcpu_restore(void);

+void xen_callback_vector(void);
+void init_shared_info(void);
+
void __init xen_build_dynamic_phys_to_machine(void);

void xen_init_irq_ops(void);
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 2ac4440..a73edd8 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -8,15 +8,20 @@
#include <linux/sysrq.h>
#include <linux/stop_machine.h>
#include <linux/freezer.h>
+#include <linux/pci.h>
+#include <linux/cpumask.h>

+#include <xen/xen.h>
#include <xen/xenbus.h>
#include <xen/grant_table.h>
#include <xen/events.h>
#include <xen/hvc-console.h>
#include <xen/xen-ops.h>
+#include <xen/platform_pci.h>

#include <asm/xen/hypercall.h>
#include <asm/xen/page.h>
+#include <asm/xen/hypervisor.h>

enum shutdown_state {
SHUTDOWN_INVALID = -1,
@@ -33,10 +38,30 @@ 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();
+ platform_pci_resume();
+ }
+
+ return 0;
+}
+
+static int xen_suspend(void *data)
+{
int err;
+ int *cancelled = data;

BUG_ON(!irqs_disabled());

@@ -73,6 +98,53 @@ static int xen_suspend(void *data)
return 0;
}

+static void do_hvm_suspend(void)
+{
+ int err;
+ int cancelled = 1;
+
+ shutting_down = SHUTDOWN_SUSPEND;
+
+#ifdef CONFIG_PREEMPT
+ /* If the kernel is preemptible, we need to freeze all the processes
+ to prevent them from being in the middle of a pagetable update
+ during suspend. */
+ err = freeze_processes();
+ if (err) {
+ printk(KERN_ERR "xen suspend: freeze failed %d\n", err);
+ goto out;
+ }
+#endif
+
+ printk(KERN_DEBUG "suspending xenstore... ");
+ xenbus_suspend();
+ printk(KERN_DEBUG "xenstore suspended\n");
+ platform_pci_disable_irq();
+
+ err = stop_machine(xen_hvm_suspend, &cancelled, cpumask_of(0));
+ if (err) {
+ printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
+ cancelled = 1;
+ }
+
+ platform_pci_enable_irq();
+
+ if (!cancelled) {
+ xen_arch_resume();
+ xenbus_resume();
+ } else
+ xs_suspend_cancel();
+
+ /* Make sure timer events get retriggered on all CPUs */
+ clock_was_set();
+
+#ifdef CONFIG_PREEMPT
+ thaw_processes();
+out:
+#endif
+ shutting_down = SHUTDOWN_INVALID;
+}
+
static void do_suspend(void)
{
int err;
@@ -185,7 +257,10 @@ static void shutdown_handler(struct xenbus_watch *watch,
ctrl_alt_del();
#ifdef CONFIG_PM_SLEEP
} else if (strcmp(str, "suspend") == 0) {
- do_suspend();
+ if (xen_hvm_domain())
+ do_hvm_suspend();
+ else
+ do_suspend();
#endif
} else {
printk(KERN_INFO "Ignoring shutdown request: %s\n", str);
@@ -261,7 +336,19 @@ 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
@@ -271,4 +358,4 @@ static int __init setup_shutdown_event(void)
return 0;
}

-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 7a8da66..b15f809 100644
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -33,6 +33,7 @@
#include <xen/xenbus.h>
#include <xen/events.h>
#include <xen/hvm.h>
+#include <xen/xen-ops.h>

#define DRV_NAME "xen-platform-pci"

@@ -43,6 +44,8 @@ MODULE_LICENSE("GPL");
static unsigned long platform_mmio;
static unsigned long platform_mmio_alloc;
static unsigned long platform_mmiolen;
+static uint64_t callback_via;
+struct pci_dev *xen_platform_pdev;

unsigned long alloc_xen_mmio(unsigned long len)
{
@@ -87,13 +90,33 @@ static int xen_allocate_irq(struct pci_dev *pdev)
"xen-platform-pci", pdev);
}

+void platform_pci_disable_irq(void)
+{
+ printk(KERN_DEBUG "platform_pci_disable_irq\n");
+ disable_irq(xen_platform_pdev->irq);
+}
+
+void platform_pci_enable_irq(void)
+{
+ printk(KERN_DEBUG "platform_pci_enable_irq\n");
+ enable_irq(xen_platform_pdev->irq);
+}
+
+void platform_pci_resume(void)
+{
+ if (!xen_have_vector_callback && xen_set_callback_via(callback_via)) {
+ printk("platform_pci_resume failure!\n");
+ return;
+ }
+}
+
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;
+ xen_platform_pdev = pdev;

i = pci_enable_device(pdev);
if (i)
@@ -152,6 +175,10 @@ static int __devinit platform_pci_init(struct pci_dev *pdev,
ret = xenbus_probe_init();
if (ret)
goto out;
+ ret = xen_setup_shutdown_event();
+ if (ret)
+ goto out;
+

out:
if (ret) {
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index dc6ed06..a679205 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -746,6 +746,34 @@ static int xenbus_dev_resume(struct device *dev)
return 0;
}

+static int dev_suspend(struct device *dev, void *data)
+{
+ return xenbus_dev_suspend(dev, PMSG_SUSPEND);
+}
+
+void xenbus_suspend(void)
+{
+ DPRINTK("");
+
+ bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, dev_suspend);
+ xs_suspend();
+}
+EXPORT_SYMBOL_GPL(xenbus_suspend);
+
+static int dev_resume(struct device *dev, void *data)
+{
+ return xenbus_dev_resume(dev);
+}
+
+void xenbus_resume(void)
+{
+ DPRINTK("");
+
+ xs_resume();
+ bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, dev_resume);
+}
+EXPORT_SYMBOL_GPL(xenbus_resume);
+
/* A flag to determine if xenstored is 'ready' (i.e. has started) */
int xenstored_ready = 0;

diff --git a/include/xen/platform_pci.h b/include/xen/platform_pci.h
index 59a120c..ced434d 100644
--- a/include/xen/platform_pci.h
+++ b/include/xen/platform_pci.h
@@ -31,11 +31,17 @@

#ifdef CONFIG_XEN_PLATFORM_PCI
unsigned long alloc_xen_mmio(unsigned long len);
+void platform_pci_resume(void);
+void platform_pci_disable_irq(void);
+void platform_pci_enable_irq(void);
#else
static inline unsigned long alloc_xen_mmio(unsigned long len)
{
return ~0UL;
}
+static inline void platform_pci_resume(void) {}
+static inline void platform_pci_disable_irq(void) {}
+static inline void platform_pci_enable_irq(void) {}
#endif

#endif /* _XEN_PLATFORM_PCI_H */
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index 883a21b..46bc81e 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 */
--
1.5.4.3

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