From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vitaly Kuznetsov Subject: [PATCH v6 2/7] KVM: x86: hyperv: optimize 'all cpus' case in kvm_hv_flush_tlb() Date: Wed, 26 Sep 2018 19:02:54 +0200 Message-ID: <20180926170259.29796-3-vkuznets@redhat.com> References: <20180926170259.29796-1-vkuznets@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Roman Kagan , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , "Michael Kelley (EOSG)" , Mohammed Gamal , Cathy Avery , Wanpeng Li , linux-kernel@vger.kernel.org To: kvm@vger.kernel.org Return-path: In-Reply-To: <20180926170259.29796-1-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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: Radim Krčmář Signed-off-by: Vitaly Kuznetsov Reviewed-by: Roman Kagan --- arch/x86/kvm/hyperv.c | 42 +++++++++++++++++++++++------------------- virt/kvm/kvm_main.c | 6 ++---- 2 files changed, 25 insertions(+), 23 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 0cd597b0f754..b45ce136be2f 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1325,35 +1325,39 @@ 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; - - /* Non-ex hypercalls can only address first 64 vCPUs */ - if (!ex && bank) - continue; + /* Banks >64 can't be represented */ + if (bank >= 64) + continue; - if (ex) { - /* - * 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); + /* Non-ex hypercalls can only address first 64 vCPUs */ + if (!ex && bank) + continue; - if (sbank < 0) - continue; - } + if (ex) { + /* + * 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); - if (!(sparse_banks[sbank] & BIT_ULL(hv->vp_index % 64))) + if (sbank < 0) continue; } + 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 * can't analyze it here, flush TLB regardless of the specified diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f986e31fa68c..587e1a0a8715 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -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; -- 2.17.1