Re: [PATCH 06/11] Add suspend\resume support for PV on HVM guests.

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 05/24/2010 11:27 AM, Stefano Stabellini wrote:
> 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@eu.citrix.com>
> ---
>  arch/x86/xen/enlighten.c   |   14 +++++++++---
>  arch/x86/xen/suspend.c     |    6 +++++
>  arch/x86/xen/xen-ops.h     |    1 +
>  drivers/xen/manage.c       |   45 ++++++++++++++++++++++++++++++++++++++++---
>  drivers/xen/platform-pci.c |   23 +++++++++++++++++++++-
>  include/xen/xen-ops.h      |    3 ++
>  6 files changed, 83 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index ed34b30..cb316b5 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 init_shared_info(void)
>   

This needs a xen_ prefix.

    J

>  {
> +	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;
> @@ -1280,7 +1282,11 @@ static void __init init_shared_info(void)
>  
>  	/* Don't do the full vcpu_info placement stuff until we have a
>  	   possible map and a non-dummy shared_info. */
> -	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
> +	/* init_shared_info is run at resume time too, 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,
> diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c
> index 987267f..ef517ee 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 0d0e0e6..caf89ee 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 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 0f78318..70395c9 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) {
> +		printk("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)
> @@ -145,6 +159,10 @@ 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) {
> @@ -168,6 +186,9 @@ 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 */
>