diff options
| -rw-r--r-- | arch/x86/Kconfig | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/cpuidle_haltpoll.h | 8 | ||||
| -rw-r--r-- | arch/x86/kernel/kvm.c | 42 | ||||
| -rw-r--r-- | drivers/cpuidle/cpuidle-haltpoll.c | 9 | ||||
| -rw-r--r-- | include/linux/cpuidle_haltpoll.h | 16 |
5 files changed, 81 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 222855cc0158..05e78acb187c 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -794,6 +794,7 @@ config KVM_GUEST bool "KVM Guest support (including kvmclock)" depends on PARAVIRT select PARAVIRT_CLOCK + select ARCH_CPUIDLE_HALTPOLL default y ---help--- This option enables various optimizations for running under the KVM @@ -802,6 +803,12 @@ config KVM_GUEST underlying device model, the host provides the guest with timing infrastructure such as time of day, and system time +config ARCH_CPUIDLE_HALTPOLL + def_bool n + prompt "Disable host haltpoll when loading haltpoll driver" + help + If virtualized under KVM, disable host haltpoll. + config PVH bool "Support for running PVH guests" ---help--- diff --git a/arch/x86/include/asm/cpuidle_haltpoll.h b/arch/x86/include/asm/cpuidle_haltpoll.h new file mode 100644 index 000000000000..ff8607d81526 --- /dev/null +++ b/arch/x86/include/asm/cpuidle_haltpoll.h @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ARCH_HALTPOLL_H +#define _ARCH_HALTPOLL_H + +void arch_haltpoll_enable(void); +void arch_haltpoll_disable(void); + +#endif diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index b7f34fe2171e..f48401be8ce0 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -875,3 +875,45 @@ void __init kvm_spinlock_init(void) } #endif /* CONFIG_PARAVIRT_SPINLOCKS */ + +#ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL + +static void kvm_disable_host_haltpoll(void *i) +{ + wrmsrl(MSR_KVM_POLL_CONTROL, 0); +} + +static void kvm_enable_host_haltpoll(void *i) +{ + wrmsrl(MSR_KVM_POLL_CONTROL, 1); +} + +void arch_haltpoll_enable(void) +{ + if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) { + printk(KERN_ERR "kvm: host does not support poll control\n"); + printk(KERN_ERR "kvm: host upgrade recommended\n"); + return; + } + + preempt_disable(); + /* Enable guest halt poll disables host halt poll */ + kvm_disable_host_haltpoll(NULL); + smp_call_function(kvm_disable_host_haltpoll, NULL, 1); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(arch_haltpoll_enable); + +void arch_haltpoll_disable(void) +{ + if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) + return; + + preempt_disable(); + /* Enable guest halt poll disables host halt poll */ + kvm_enable_host_haltpoll(NULL); + smp_call_function(kvm_enable_host_haltpoll, NULL, 1); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(arch_haltpoll_disable); +#endif diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c index 35cfb53e9287..9ac093dcbb01 100644 --- a/drivers/cpuidle/cpuidle-haltpoll.c +++ b/drivers/cpuidle/cpuidle-haltpoll.c @@ -15,6 +15,7 @@ #include <linux/module.h> #include <linux/sched/idle.h> #include <linux/kvm_para.h> +#include <linux/cpuidle_haltpoll.h> static int default_enter_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) @@ -47,6 +48,7 @@ static struct cpuidle_driver haltpoll_driver = { static int __init haltpoll_init(void) { + int ret; struct cpuidle_driver *drv = &haltpoll_driver; cpuidle_poll_state_init(drv); @@ -54,11 +56,16 @@ static int __init haltpoll_init(void) if (!kvm_para_available()) return 0; - return cpuidle_register(&haltpoll_driver, NULL); + ret = cpuidle_register(&haltpoll_driver, NULL); + if (ret == 0) + arch_haltpoll_enable(); + + return ret; } static void __exit haltpoll_exit(void) { + arch_haltpoll_disable(); cpuidle_unregister(&haltpoll_driver); } diff --git a/include/linux/cpuidle_haltpoll.h b/include/linux/cpuidle_haltpoll.h new file mode 100644 index 000000000000..fe5954c2409e --- /dev/null +++ b/include/linux/cpuidle_haltpoll.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _CPUIDLE_HALTPOLL_H +#define _CPUIDLE_HALTPOLL_H + +#ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL +#include <asm/cpuidle_haltpoll.h> +#else +static inline void arch_haltpoll_enable(void) +{ +} + +static inline void arch_haltpoll_disable(void) +{ +} +#endif +#endif |