Re: [PATCH v5 22/23] KVM: arm64: GICv4.1: Allow non-trapping WFI when using HW SGIs

From: Zenghui Yu
Date: Fri Mar 20 2020 - 00:23:36 EST


Hi Marc,

On 2020/3/5 4:33, Marc Zyngier wrote:
Just like for VLPIs, it is beneficial to avoid trapping on WFI when the
vcpu is using the GICv4.1 SGIs.

Add such a check to vcpu_clear_wfx_traps().

Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>

Reviewed-by: Zenghui Yu <yuzenghui@xxxxxxxxxx>


Thanks

---
arch/arm64/include/asm/kvm_emulate.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index f658dda12364..a30b4eec7cb4 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -89,7 +89,8 @@ static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
static inline void vcpu_clear_wfx_traps(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 &= ~HCR_TWE;
- if (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count))
+ if (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count) ||
+ vcpu->kvm->arch.vgic.nassgireq)
vcpu->arch.hcr_el2 &= ~HCR_TWI;
else
vcpu->arch.hcr_el2 |= HCR_TWI;