Commit a2252278 authored by Zenghui Yu's avatar Zenghui Yu Committed by Yang Yingliang
Browse files

KVM: arm64: Only flush VM for the first and the last vcpu 



euleros inclusion
category: bugfix

-------------------------------------------------

stage_flush_vm() can be pretty time-consuming if lots of stage-2 mappings
had been setup before booting secondary processors. Sidestep the heavy
D-cache maintenance operations on D05 *only*.

Signed-off-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Reviewed-by: default avatarzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parent ae0237a0

virt/kvm/arm/mmu.c

+14 −1
Original line number Diff line number Diff line
@@ -2474,6 +2474,19 @@ void kvm_set_way_flush(struct kvm_vcpu *vcpu) 
	}

}



static bool kvm_need_flush_vm(struct kvm_vcpu *vcpu)

{

	if (kvm_ncsnp_support)

		return false;



	/* Hackish... */

	if (vcpu->vcpu_id == 0 || (vcpu->vcpu_id + 1 ==

				   atomic_read(&vcpu->kvm->online_vcpus)))

		return true;



	return false;

}



void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)

{

	bool now_enabled = vcpu_has_cache_enabled(vcpu);
@@ -2483,7 +2496,7 @@ void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled) 
	 * If switching it off, need to clean the caches.

	 * Clean + invalidate does the trick always.

	 */

	if (now_enabled != was_enabled && !kvm_ncsnp_support)

	if (now_enabled != was_enabled && kvm_need_flush_vm(vcpu))

		stage2_flush_vm(vcpu->kvm);



	/* Caches are now on, stop trapping VM ops (until a S/W op) */