diff options
| author | Marc Zyngier <marc.zyngier@arm.com> | 2018-06-21 10:43:59 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2018-07-09 11:38:24 +0100 |
| commit | de73708915adc1b3f05e617a86da6b2d68fae141 (patch) | |
| tree | 37f70c868acf33f7645e67c42b599cd5034614c4 /arch | |
| parent | 0a72a5ab9feb8ba6101b00bbcac14cdbae1d1df7 (diff) | |
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 <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/kvm_emulate.h | 10 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_emulate.h | 10 |
2 files changed, 20 insertions, 0 deletions
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; diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index dd98fdf33d99..bfefdd9a72eb 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -83,6 +83,16 @@ static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu) return (unsigned long *)&vcpu->arch.hcr_el2; } +static inline void vcpu_clear_wfe_traps(struct kvm_vcpu *vcpu) +{ + vcpu->arch.hcr_el2 &= ~HCR_TWE; +} + +static inline void vcpu_set_wfe_traps(struct kvm_vcpu *vcpu) +{ + vcpu->arch.hcr_el2 |= HCR_TWE; +} + static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr) { vcpu->arch.vsesr_el2 = vsesr; |