From de73708915adc1b3f05e617a86da6b2d68fae141 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 21 Jun 2018 10:43:59 +0100 Subject: KVM: arm/arm64: Enable adaptative WFE trapping Trapping blocking WFE is extremely beneficial in situations where the system is oversubscribed, as it allows another thread to run while being blocked. In a non-oversubscribed environment, this is the complete opposite, and trapping WFE is just unnecessary overhead. Let's only enable WFE trapping if the CPU has more than a single task to run (that is, more than just the vcpu thread). Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm/include/asm/kvm_emulate.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/arm/include/asm/kvm_emulate.h') diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h index 6493bd479ddc..b50fe8380868 100644 --- a/arch/arm/include/asm/kvm_emulate.h +++ b/arch/arm/include/asm/kvm_emulate.h @@ -107,6 +107,16 @@ static inline unsigned long *vcpu_hcr(const struct kvm_vcpu *vcpu) return (unsigned long *)&vcpu->arch.hcr; } +static inline void vcpu_clear_wfe_traps(struct kvm_vcpu *vcpu) +{ + vcpu->arch.hcr &= ~HCR_TWE; +} + +static inline void vcpu_set_wfe_traps(struct kvm_vcpu *vcpu) +{ + vcpu->arch.hcr |= HCR_TWE; +} + static inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu) { return 1; -- cgit