Commit 6470accc authored Sep 03, 2021 by Vitaly Kuznetsov Committed by Paolo Bonzini Sep 30, 2021

KVM: x86: hyper-v: Avoid calling kvm_make_vcpus_request_mask() with vcpu_mask==NULL



In preparation to making kvm_make_vcpus_request_mask() use for_each_set_bit()
switch kvm_hv_flush_tlb() to calling kvm_make_all_cpus_request() for 'all cpus'
case.

Note: kvm_make_all_cpus_request() (unlike kvm_make_vcpus_request_mask())
currently dynamically allocates cpumask on each call and this is suboptimal.
Both kvm_make_all_cpus_request() and kvm_make_vcpus_request_mask() are
going to be switched to using pre-allocated per-cpu masks.

Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210903075141.403071-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 11476d27

arch/x86/kvm/hyperv.c

+9 −6

Original line number	Diff line number	Diff line
		@@ -1838,16 +1838,19 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu vcpu, struct kvm_hv_hcall hc, bool

		cpumask_clear(&hv_vcpu->tlb_flush);

		vcpu_mask = all_cpus ? NULL :
		sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
		vp_bitmap, vcpu_bitmap);

		/*
		* vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
		* analyze it here, flush TLB regardless of the specified address space.
		*/
		if (all_cpus) {
		kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH_GUEST);
		} else {
		vcpu_mask = sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
		vp_bitmap, vcpu_bitmap);

		kvm_make_vcpus_request_mask(kvm, KVM_REQ_TLB_FLUSH_GUEST,
		NULL, vcpu_mask, &hv_vcpu->tlb_flush);
		}

		ret_success:
		/* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */