[PATCH 05/13] Add suspend\resume support for PV on HVM guests.

From: stefano
Date: Mon Jun 21 2010 - 12:24:13 EST


From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>

Suspend\resume requires few different thing on HVM: the suspend
hypercall is different, we don't need to save\restore any memory related
setting, but we need to reinitialize the shared info page and the
callback mechanism.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
arch/x86/xen/enlighten.c | 22 ++++++++++++++++----
arch/x86/xen/suspend.c | 6 +++++
arch/x86/xen/xen-ops.h | 1 +
drivers/xen/manage.c | 45 ++++++++++++++++++++++++++++++++++++++++---
drivers/xen/platform-pci.c | 22 ++++++++++++++++++++-
include/xen/xen-ops.h | 3 ++
6 files changed, 89 insertions(+), 10 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 4b2172d..90bac21 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1263,12 +1263,14 @@ 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 *) 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;
@@ -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,
@@ -1311,7 +1323,7 @@ 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 987267f..6ff9665 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 0d0e0e6..01c9dd3 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 2ac4440..0716ba6 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());

@@ -112,7 +134,10 @@ 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);

@@ -261,7 +286,19 @@ 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 +308,4 @@ 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 cdb2199..6663201 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;

i = pci_enable_device(pdev);
if (i)
@@ -143,6 +157,9 @@ 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;

out:
if (ret) {
@@ -166,6 +183,9 @@ 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 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 */
--
1.7.0.4

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