KVM: x86: hyperv: optimize kvm_hv_flush_tlb() for vp_index == vcpu_idx case (2cefc5fe) · Commits · 戴 / test

arch/x86/kvm/hyperv.c

+52 −44

Original line number	Diff line number	Diff line
		@@ -1277,32 +1277,37 @@ int kvm_hv_get_msr_common(struct kvm_vcpu vcpu, u32 msr, u64 pdata, bool host)
		return kvm_hv_get_msr(vcpu, msr, pdata, host);
		}

		static __always_inline int get_sparse_bank_no(u64 valid_bank_mask, int bank_no)
		static __always_inline bool hv_vcpu_in_sparse_set(struct kvm_vcpu_hv *hv_vcpu,
		u64 sparse_banks[],
		u64 valid_bank_mask)
		{
		int i = 0, j;
		int bank = hv_vcpu->vp_index / 64, sbank;

		if (!(valid_bank_mask & BIT_ULL(bank_no)))
		return -1;
		if (bank >= 64)
		return false;

		for (j = 0; j < bank_no; j++)
		if (valid_bank_mask & BIT_ULL(j))
		i++;
		if (!(valid_bank_mask & BIT_ULL(bank)))
		return false;

		/* Sparse bank number equals to the number of set bits before it */
		sbank = bitmap_weight((unsigned long *)&valid_bank_mask, bank);

		return i;
		return !!(sparse_banks[sbank] & BIT_ULL(hv_vcpu->vp_index % 64));
		}

		static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa,
		u16 rep_cnt, bool ex)
		{
		struct kvm *kvm = current_vcpu->kvm;
		struct kvm_vcpu_hv *hv_current = &current_vcpu->arch.hyperv;
		struct kvm_hv *hv = &kvm->arch.hyperv;
		struct kvm_vcpu_hv *hv_vcpu = &current_vcpu->arch.hyperv;
		struct hv_tlb_flush_ex flush_ex;
		struct hv_tlb_flush flush;
		struct kvm_vcpu *vcpu;
		unsigned long vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)] = {0};
		u64 valid_bank_mask = 0;
		u64 valid_bank_mask;
		u64 sparse_banks[64];
		int sparse_banks_len, i;
		int sparse_banks_len, i, bank, sbank;
		bool all_cpus;

		if (!ex) {
		@@ -1312,6 +1317,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa,
		trace_kvm_hv_flush_tlb(flush.processor_mask,
		flush.address_space, flush.flags);

		valid_bank_mask = BIT_ULL(0);
		sparse_banks[0] = flush.processor_mask;
		all_cpus = flush.flags & HV_FLUSH_ALL_PROCESSORS;
		} else {
		@@ -1344,52 +1350,54 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *current_vcpu, u64 ingpa,
		return HV_STATUS_INVALID_HYPERCALL_INPUT;
		}

		cpumask_clear(&hv_current->tlb_lush);
		/*
		* 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.
		*/
		cpumask_clear(&hv_vcpu->tlb_lush);

		if (all_cpus) {
		kvm_make_vcpus_request_mask(kvm,
		KVM_REQ_TLB_FLUSH \| KVM_REQUEST_NO_WAKEUP,
		NULL, &hv_current->tlb_lush);
		NULL, &hv_vcpu->tlb_lush);
		goto ret_success;
		}

		if (atomic_read(&hv->num_mismatched_vp_indexes)) {
		kvm_for_each_vcpu(i, vcpu, kvm) {
		struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
		int bank = hv->vp_index / 64, sbank = 0;

		/* Banks >64 can't be represented */
		if (bank >= 64)
		continue;

		/* Non-ex hypercalls can only address first 64 vCPUs */
		if (!ex && bank)
		continue;
		if (hv_vcpu_in_sparse_set(&vcpu->arch.hyperv,
		sparse_banks,
		valid_bank_mask))
		__set_bit(i, vcpu_bitmap);
		}
		goto flush_request;
		}

		if (ex) {
		/*
		* Check is the bank of this vCPU is in sparse
		* set and get the sparse bank number.
		* num_mismatched_vp_indexes is zero so every vcpu has
		* vp_index == vcpu_idx.
		*/
		sbank = get_sparse_bank_no(valid_bank_mask, bank);
		sbank = 0;
		for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
		BITS_PER_LONG) {
		for_each_set_bit(i,
		(unsigned long *)&sparse_banks[sbank],
		BITS_PER_LONG) {
		u32 vp_index = bank * 64 + i;

		/* A non-existent vCPU was specified */
		if (vp_index >= KVM_MAX_VCPUS)
		return HV_STATUS_INVALID_HYPERCALL_INPUT;

		if (sbank < 0)
		continue;
		__set_bit(vp_index, vcpu_bitmap);
		}

		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
		* address space.
		*/
		__set_bit(i, vcpu_bitmap);
		sbank++;
		}

		flush_request:
		kvm_make_vcpus_request_mask(kvm,
		KVM_REQ_TLB_FLUSH \| KVM_REQUEST_NO_WAKEUP,
		vcpu_bitmap, &hv_current->tlb_lush);
		vcpu_bitmap, &hv_vcpu->tlb_lush);

		ret_success:
		/* We always do full TLB flush, set rep_done = rep_cnt. */

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