[Xen-devel] [PATCH 1/3] xen/arm: Enable cpu_hotplug.c

[Konrad Rzeszutek Wilk]

On October 14, 2015 1:49:55 PM EDT, Stefano Stabellini <stefano.stabellini at eu.citrix.com> wrote:
>Build cpu_hotplug for ARM and ARM64 guests.
>
>Rename arch_(un)register_cpu to xen_(un)register_cpu and provide an
>empty implementation on ARM and ARM64. On x86 just call
>arch_(un)register_cpu as we are already doing.
>
>Initialize cpu_hotplug on ARM.

Have you tested this on x86? As your changes touch the generic code path.

>
>Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
>---
> arch/arm/include/asm/xen/hypervisor.h |    8 ++++++++
> arch/x86/include/asm/xen/hypervisor.h |    5 +++++
> arch/x86/xen/enlighten.c              |   15 +++++++++++++++
> drivers/xen/Makefile                  |    2 --
> drivers/xen/cpu_hotplug.c             |    6 ++++--
> 5 files changed, 32 insertions(+), 4 deletions(-)
>
>diff --git a/arch/arm/include/asm/xen/hypervisor.h
>b/arch/arm/include/asm/xen/hypervisor.h
>index 04ff8e7..2bc418a 100644
>--- a/arch/arm/include/asm/xen/hypervisor.h
>+++ b/arch/arm/include/asm/xen/hypervisor.h
>@@ -26,4 +26,12 @@ void __init xen_early_init(void);
> static inline void xen_early_init(void) { return; }
> #endif
> 
>+static inline void xen_arch_register_cpu(int num)
>+{
>+}
>+
>+static inline void xen_arch_unregister_cpu(int num)
>+{
>+}
>+
> #endif /* _ASM_ARM_XEN_HYPERVISOR_H */
>diff --git a/arch/x86/include/asm/xen/hypervisor.h
>b/arch/x86/include/asm/xen/hypervisor.h
>index d866959..8b2d4be 100644
>--- a/arch/x86/include/asm/xen/hypervisor.h
>+++ b/arch/x86/include/asm/xen/hypervisor.h
>@@ -57,4 +57,9 @@ static inline bool xen_x2apic_para_available(void)
> }
> #endif
> 
>+#ifdef CONFIG_HOTPLUG_CPU
>+void xen_arch_register_cpu(int num);
>+void xen_arch_unregister_cpu(int num);
>+#endif
>+
> #endif /* _ASM_X86_XEN_HYPERVISOR_H */
>diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
>index 11d6fb4..ba62d8e 100644
>--- a/arch/x86/xen/enlighten.c
>+++ b/arch/x86/xen/enlighten.c
>@@ -71,6 +71,7 @@
> #include <asm/mwait.h>
> #include <asm/pci_x86.h>
> #include <asm/pat.h>
>+#include <asm/cpu.h>
> 
> #ifdef CONFIG_ACPI
> #include <linux/acpi.h>
>@@ -1868,3 +1869,17 @@ const struct hypervisor_x86 x86_hyper_xen = {
> 	.set_cpu_features       = xen_set_cpu_features,
> };
> EXPORT_SYMBOL(x86_hyper_xen);
>+
>+#ifdef CONFIG_HOTPLUG_CPU
>+void xen_arch_register_cpu(int num)
>+{
>+	arch_register_cpu(num);
>+}
>+EXPORT_SYMBOL(xen_arch_register_cpu);
>+
>+void xen_arch_unregister_cpu(int num)
>+{
>+	arch_unregister_cpu(num);
>+}
>+EXPORT_SYMBOL(xen_arch_unregister_cpu);
>+#endif
>diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
>index e293bc5..aa8a7f7 100644
>--- a/drivers/xen/Makefile
>+++ b/drivers/xen/Makefile
>@@ -1,6 +1,4 @@
>-ifeq ($(filter y, $(CONFIG_ARM) $(CONFIG_ARM64)),)
> obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
>-endif
> obj-$(CONFIG_X86)			+= fallback.o
> obj-y	+= grant-table.o features.o balloon.o manage.o preempt.o
> obj-y	+= events/
>diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
>index cc6513a..122b351 100644
>--- a/drivers/xen/cpu_hotplug.c
>+++ b/drivers/xen/cpu_hotplug.c
>@@ -11,7 +11,7 @@
> static void enable_hotplug_cpu(int cpu)
> {
> 	if (!cpu_present(cpu))
>-		arch_register_cpu(cpu);
>+		xen_arch_register_cpu(cpu);
> 
> 	set_cpu_present(cpu, true);
> }
>@@ -19,7 +19,7 @@ static void enable_hotplug_cpu(int cpu)
> static void disable_hotplug_cpu(int cpu)
> {
> 	if (cpu_present(cpu))
>-		arch_unregister_cpu(cpu);
>+		xen_arch_unregister_cpu(cpu);
> 
> 	set_cpu_present(cpu, false);
> }
>@@ -102,8 +102,10 @@ static int __init setup_vcpu_hotplug_event(void)
> 	static struct notifier_block xsn_cpu = {
> 		.notifier_call = setup_cpu_watcher };
> 
>+#ifdef CONFIG_X86
> 	if (!xen_pv_domain())
> 		return -ENODEV;
>+#endif
> 
> 	register_xenstore_notifier(&xsn_cpu);
>