From patchwork Wed May 25 09:01:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12860824 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7AF3C433F5 for ; Wed, 25 May 2022 09:02:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237753AbiEYJCD (ORCPT ); Wed, 25 May 2022 05:02:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237988AbiEYJB5 (ORCPT ); Wed, 25 May 2022 05:01:57 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D648C7A818 for ; Wed, 25 May 2022 02:01:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653469312; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6uqBm3igjiTkZoAEa3llRLTCNMOe2Jyrla567Yi0Bdc=; b=CtKewDcQlm4JR1+JrkunkL5lQjxrOYhIbfReR6xSVAYC2Y7IptOC+oHsTjQclxAHMdRajZ 75YL16muY5qKeLoMPLTwZip7KaoVlZ/nzRQEQsiF5WLkOhnhbL7kMlmRfIjSJZUnWeEado YcdmHqVDSrR6IrTOc/2f9LFCkD3nQuE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-31-yn3vHqUlOcGik_o_HcWBZQ-1; Wed, 25 May 2022 05:01:48 -0400 X-MC-Unique: yn3vHqUlOcGik_o_HcWBZQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B97913C10236; Wed, 25 May 2022 09:01:47 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.186]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0B00F40CFD0A; Wed, 25 May 2022 09:01:45 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Maxim Levitsky , Wanpeng Li , Jim Mattson , Michael Kelley , Siddharth Chandrasekaran , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 05/37] KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls gently Date: Wed, 25 May 2022 11:01:01 +0200 Message-Id: <20220525090133.1264239-6-vkuznets@redhat.com> In-Reply-To: <20220525090133.1264239-1-vkuznets@redhat.com> References: <20220525090133.1264239-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Currently, HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls are handled the exact same way as HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE{,EX}: by flushing the whole VPID and this is sub-optimal. Switch to handling these requests with 'flush_tlb_gva()' hooks instead. Use the newly introduced TLB flush fifo to queue the requests. Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/hyperv.c | 102 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 90 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 762b0b699fdf..576749973727 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1806,32 +1806,84 @@ static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc, sparse_banks, consumed_xmm_halves, offset); } -static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu) +static int kvm_hv_get_tlb_flush_entries(struct kvm *kvm, struct kvm_hv_hcall *hc, u64 entries[], + int consumed_xmm_halves, gpa_t offset) +{ + return kvm_hv_get_hc_data(kvm, hc, hc->rep_cnt, hc->rep_cnt, + entries, consumed_xmm_halves, offset); +} + +static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu, u64 *entries, int count) { struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo; struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); u64 entry = KVM_HV_TLB_FLUSHALL_ENTRY; + unsigned long flags; if (!hv_vcpu) return; tlb_flush_fifo = &hv_vcpu->tlb_flush_fifo; - kfifo_in_spinlocked(&tlb_flush_fifo->entries, &entry, 1, &tlb_flush_fifo->write_lock); + spin_lock_irqsave(&tlb_flush_fifo->write_lock, flags); + + /* + * All entries should fit on the fifo leaving one free for 'flush all' + * entry in case another request comes in. In case there's not enough + * space, just put 'flush all' entry there. + */ + if (count && entries && count < kfifo_avail(&tlb_flush_fifo->entries)) { + WARN_ON(kfifo_in(&tlb_flush_fifo->entries, entries, count) != count); + goto out_unlock; + } + + /* + * Note: full fifo always contains 'flush all' entry, no need to check the + * return value. + */ + kfifo_in(&tlb_flush_fifo->entries, &entry, 1); + +out_unlock: + spin_unlock_irqrestore(&tlb_flush_fifo->write_lock, flags); } void kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu) { struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo; struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu); + u64 entries[KVM_HV_TLB_FLUSH_FIFO_SIZE]; + int i, j, count; + gva_t gva; - kvm_vcpu_flush_tlb_guest(vcpu); - - if (!hv_vcpu) + if (!tdp_enabled || !hv_vcpu) { + kvm_vcpu_flush_tlb_guest(vcpu); return; + } tlb_flush_fifo = &hv_vcpu->tlb_flush_fifo; + count = kfifo_out(&tlb_flush_fifo->entries, entries, KVM_HV_TLB_FLUSH_FIFO_SIZE); + + for (i = 0; i < count; i++) { + if (entries[i] == KVM_HV_TLB_FLUSHALL_ENTRY) + goto out_flush_all; + + /* + * Lower 12 bits of 'address' encode the number of additional + * pages to flush. + */ + gva = entries[i] & PAGE_MASK; + for (j = 0; j < (entries[i] & ~PAGE_MASK) + 1; j++) + static_call(kvm_x86_flush_tlb_gva)(vcpu, gva + j * PAGE_SIZE); + + ++vcpu->stat.tlb_flush; + } + goto out_empty_ring; + +out_flush_all: + kvm_vcpu_flush_tlb_guest(vcpu); + +out_empty_ring: kfifo_reset_out(&tlb_flush_fifo->entries); } @@ -1841,11 +1893,21 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) struct hv_tlb_flush_ex flush_ex; struct hv_tlb_flush flush; DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS); + /* + * Normally, there can be no more than 'KVM_HV_TLB_FLUSH_FIFO_SIZE' + * entries on the TLB flush fifo. The last entry, however, needs to be + * always left free for 'flush all' entry which gets placed when + * there is not enough space to put all the requested entries. + */ + u64 __tlb_flush_entries[KVM_HV_TLB_FLUSH_FIFO_SIZE - 1]; + u64 *tlb_flush_entries; u64 valid_bank_mask; u64 sparse_banks[KVM_HV_MAX_SPARSE_VCPU_SET_BITS]; struct kvm_vcpu *v; unsigned long i; bool all_cpus; + int consumed_xmm_halves = 0; + gpa_t data_offset; /* * The Hyper-V TLFS doesn't allow more than 64 sparse banks, e.g. the @@ -1861,10 +1923,12 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) flush.address_space = hc->ingpa; flush.flags = hc->outgpa; flush.processor_mask = sse128_lo(hc->xmm[0]); + consumed_xmm_halves = 1; } else { if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush, sizeof(flush)))) return HV_STATUS_INVALID_HYPERCALL_INPUT; + data_offset = sizeof(flush); } trace_kvm_hv_flush_tlb(flush.processor_mask, @@ -1888,10 +1952,12 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) flush_ex.flags = hc->outgpa; memcpy(&flush_ex.hv_vp_set, &hc->xmm[0], sizeof(hc->xmm[0])); + consumed_xmm_halves = 2; } else { if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex, sizeof(flush_ex)))) return HV_STATUS_INVALID_HYPERCALL_INPUT; + data_offset = sizeof(flush_ex); } trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask, @@ -1907,25 +1973,37 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) return HV_STATUS_INVALID_HYPERCALL_INPUT; if (all_cpus) - goto do_flush; + goto read_flush_entries; if (!hc->var_cnt) goto ret_success; - if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks, 2, - offsetof(struct hv_tlb_flush_ex, - hv_vp_set.bank_contents))) + if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks, consumed_xmm_halves, + data_offset)) + return HV_STATUS_INVALID_HYPERCALL_INPUT; + data_offset += hc->var_cnt * sizeof(sparse_banks[0]); + consumed_xmm_halves += hc->var_cnt; + } + +read_flush_entries: + if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE || + hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX || + hc->rep_cnt > ARRAY_SIZE(__tlb_flush_entries)) { + tlb_flush_entries = NULL; + } else { + if (kvm_hv_get_tlb_flush_entries(kvm, hc, __tlb_flush_entries, + consumed_xmm_halves, data_offset)) return HV_STATUS_INVALID_HYPERCALL_INPUT; + tlb_flush_entries = __tlb_flush_entries; } -do_flush: /* * 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_for_each_vcpu(i, v, kvm) - hv_tlb_flush_enqueue(v); + hv_tlb_flush_enqueue(v, tlb_flush_entries, hc->rep_cnt); kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH); } else { @@ -1935,7 +2013,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) v = kvm_get_vcpu(kvm, i); if (!v) continue; - hv_tlb_flush_enqueue(v); + hv_tlb_flush_enqueue(v, tlb_flush_entries, hc->rep_cnt); } kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);