diff options
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index f518b8d7a5b5..3b18a665ef4c 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -33,6 +33,7 @@ #include <linux/hyperv.h> #include <linux/kernel_stat.h> #include <linux/clockchips.h> +#include <linux/cpu.h> #include <asm/hyperv.h> #include <asm/hypervisor.h> #include <asm/mshyperv.h> @@ -704,6 +705,39 @@ static void vmbus_isr(void) } } +#ifdef CONFIG_HOTPLUG_CPU +static int hyperv_cpu_disable(void) +{ + return -ENOSYS; +} + +static void hv_cpu_hotplug_quirk(bool vmbus_loaded) +{ + static void *previous_cpu_disable; + + /* + * Offlining a CPU when running on newer hypervisors (WS2012R2, Win8, + * ...) is not supported at this moment as channel interrupts are + * distributed across all of them. + */ + + if ((vmbus_proto_version == VERSION_WS2008) || + (vmbus_proto_version == VERSION_WIN7)) + return; + + if (vmbus_loaded) { + previous_cpu_disable = smp_ops.cpu_disable; + smp_ops.cpu_disable = hyperv_cpu_disable; + pr_notice("CPU offlining is not supported by hypervisor\n"); + } else if (previous_cpu_disable) + smp_ops.cpu_disable = previous_cpu_disable; +} +#else +static void hv_cpu_hotplug_quirk(bool vmbus_loaded) +{ +} +#endif + /* * vmbus_bus_init -Main vmbus driver initialization routine. * @@ -744,6 +778,7 @@ static int vmbus_bus_init(int irq) if (ret) goto err_alloc; + hv_cpu_hotplug_quirk(true); vmbus_request_offers(); return 0; @@ -997,6 +1032,7 @@ static void __exit vmbus_exit(void) bus_unregister(&hv_bus); hv_cleanup(); acpi_bus_unregister_driver(&vmbus_acpi_driver); + hv_cpu_hotplug_quirk(false); } |