diff options
| author | Marcelo Tosatti <mtosatti@redhat.com> | 2019-07-03 20:51:29 -0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-07-30 17:27:37 +0200 |
| commit | a1c4423b02b2121108e3ea9580741e0f26309a48 (patch) | |
| tree | c2b6c2842065c7ed359f997580078ca00ad02fe3 /arch | |
| parent | 2cffe9f6b96fece065ee8522673c90e92ef2085d (diff) | |
cpuidle-haltpoll: disable host side polling when kvm virtualized
When performing guest side polling, it is not necessary to
also perform host side polling.
So disable host side polling, via the new MSR interface,
when loading cpuidle-haltpoll driver.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'arch')
| -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 |
3 files changed, 57 insertions, 0 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 |