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

[Stefano Stabellini]

On Wed, 14 Oct 2015, Stefano Stabellini wrote:
> On Wed, 14 Oct 2015, Konrad Rzeszutek Wilk wrote:
> > 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.
> 
> Only build-tested at this stage, because all my x86 test boxes are
> unavailable at the moment (they are being relocated). As soon as they
> come back online I will test.

Tested with a PV guest on x86 and it's fine.


> 
> > >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);
> > > 
> > 
> > 
>