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-rw-r--r--arch/x86/Kconfig7
-rw-r--r--arch/x86/include/asm/cpuidle_haltpoll.h8
-rw-r--r--arch/x86/kernel/kvm.c37
-rw-r--r--arch/x86/kernel/process.c2
4 files changed, 53 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 58eae28c3dd6..4195f44c6a09 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..c8b39c6716ff
--- /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(unsigned int cpu);
+void arch_haltpoll_disable(unsigned int cpu);
+
+#endif
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 4cc967178bf9..b2f56602af65 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -705,6 +705,7 @@ unsigned int kvm_arch_para_hints(void)
{
return cpuid_edx(kvm_cpuid_base() | KVM_CPUID_FEATURES);
}
+EXPORT_SYMBOL_GPL(kvm_arch_para_hints);
static uint32_t __init kvm_detect(void)
{
@@ -867,3 +868,39 @@ 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(unsigned int cpu)
+{
+ if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) {
+ pr_err_once("kvm: host does not support poll control\n");
+ pr_err_once("kvm: host upgrade recommended\n");
+ return;
+ }
+
+ /* Enable guest halt poll disables host halt poll */
+ smp_call_function_single(cpu, kvm_disable_host_haltpoll, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(arch_haltpoll_enable);
+
+void arch_haltpoll_disable(unsigned int cpu)
+{
+ if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL))
+ return;
+
+ /* Enable guest halt poll disables host halt poll */
+ smp_call_function_single(cpu, kvm_enable_host_haltpoll, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(arch_haltpoll_disable);
+#endif
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 75fea0d48c0e..5e94c4354d4e 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -580,7 +580,7 @@ void __cpuidle default_idle(void)
safe_halt();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
-#ifdef CONFIG_APM_MODULE
+#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
EXPORT_SYMBOL(default_idle);
#endif