Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a812297c authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
Browse files

KVM: x86: hyperv: optimize 'all cpus' case in kvm_hv_flush_tlb() 



We can use 'NULL' to represent 'all cpus' case in
kvm_make_vcpus_request_mask() and avoid building vCPU mask with
all vCPUs.

Suggested-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9170200e

arch/x86/kvm/hyperv.c

+23 −19
Original line number Diff line number Diff line
@@ -1325,11 +1325,17 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa, 


	cpumask_clear(&hv_current->tlb_lush);



	if (all_cpus) {

		kvm_make_vcpus_request_mask(kvm,

				    KVM_REQ_TLB_FLUSH | KVM_REQUEST_NO_WAKEUP,

				    NULL, &hv_current->tlb_lush);

		goto ret_success;

	}



	kvm_for_each_vcpu(i, vcpu, kvm) {

		struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;

		int bank = hv->vp_index / 64, sbank = 0;



		if (!all_cpus) {

		/* Banks >64 can't be represented */

		if (bank >= 64)

			continue;
@@ -1343,8 +1349,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa, 
			 * Check is the bank of this vCPU is in sparse

			 * set and get the sparse bank number.

			 */

				sbank = get_sparse_bank_no(valid_bank_mask,

							   bank);

			sbank = get_sparse_bank_no(valid_bank_mask, bank);



			if (sbank < 0)

				continue;
@@ -1352,7 +1357,6 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa, 


		if (!(sparse_banks[sbank] & BIT_ULL(hv->vp_index % 64)))

			continue;

		}



		/*

		 * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we

virt/kvm/kvm_main.c

+2 −4
Original line number Diff line number Diff line
@@ -219,7 +219,7 @@ bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req, 
	me = get_cpu();



	kvm_for_each_vcpu(i, vcpu, kvm) {

		if (!test_bit(i, vcpu_bitmap))

		if (vcpu_bitmap && !test_bit(i, vcpu_bitmap))

			continue;



		kvm_make_request(req, vcpu);
@@ -243,12 +243,10 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req) 
{

	cpumask_var_t cpus;

	bool called;

	static unsigned long vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)]

		= {[0 ... BITS_TO_LONGS(KVM_MAX_VCPUS)-1] = ULONG_MAX};



	zalloc_cpumask_var(&cpus, GFP_ATOMIC);



	called = kvm_make_vcpus_request_mask(kvm, req, vcpu_bitmap, cpus);

	called = kvm_make_vcpus_request_mask(kvm, req, NULL, cpus);



	free_cpumask_var(cpus);

	return called;