From mboxrd@z Thu Jan 1 00:00:00 1970 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 AF1F6C433F5 for ; Tue, 4 Oct 2022 12:41:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229927AbiJDMlJ (ORCPT ); Tue, 4 Oct 2022 08:41:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229840AbiJDMkt (ORCPT ); Tue, 4 Oct 2022 08:40:49 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45F995AC5D for ; Tue, 4 Oct 2022 05:40:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664887221; 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=0WWsaQHYwxyBgEXMPcBo6mNpTCnx8sKZnLNh2TLh+sU=; b=Ea5p06p/gjbz7FPm2caw5yNoWqcFzjn+7vB5cSVTRRFi9GRdR49+yNl1avCUUHnOa6mJPx Ug/TuJ5CciGbShmQIBQ3b1BwxVz9Ta24ByQYmtEsQaoH6F0CVMAogDO3Vf/vJSZV3QxbPm 57hk6loWAK8gJvYJ7sdjUUQHT9a/Rtk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-90-K7Us0rH7MPCo3DvibIGcEQ-1; Tue, 04 Oct 2022 08:40:18 -0400 X-MC-Unique: K7Us0rH7MPCo3DvibIGcEQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DA5C4882820; Tue, 4 Oct 2022 12:40:17 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.192.255]) by smtp.corp.redhat.com (Postfix) with ESMTP id EB6577AE5; Tue, 4 Oct 2022 12:40:15 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini , Sean Christopherson Cc: Wanpeng Li , Jim Mattson , Michael Kelley , Siddharth Chandrasekaran , Yuan Yao , Maxim Levitsky , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v11 07/46] KVM: x86: Move clearing of TLB_FLUSH_CURRENT to kvm_vcpu_flush_tlb_all() Date: Tue, 4 Oct 2022 14:39:17 +0200 Message-Id: <20221004123956.188909-8-vkuznets@redhat.com> In-Reply-To: <20221004123956.188909-1-vkuznets@redhat.com> References: <20221004123956.188909-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sean Christopherson Clear KVM_REQ_TLB_FLUSH_CURRENT in kvm_vcpu_flush_tlb_all() instead of in its sole caller that processes KVM_REQ_TLB_FLUSH. Regardless of why/when kvm_vcpu_flush_tlb_all() is called, flushing "all" TLB entries also flushes "current" TLB entries. Ideally, there will never be another caller of kvm_vcpu_flush_tlb_all(), and moving the handling "requires" extra work to document the ordering requirement, but future Hyper-V paravirt TLB flushing support will add similar logic for flush "guest" (Hyper-V can flush a subset of "guest" entries). And in the Hyper-V case, KVM needs to do more than just clear the request, the queue of GPAs to flush also needs to purged, and doing all only in the request path is undesirable as kvm_vcpu_flush_tlb_guest() does have multiple callers (though it's unlikely KVM's paravirt TLB flush will coincide with Hyper-V's paravirt TLB flush). Move the logic even though it adds extra "work" so that KVM will be consistent with how flush requests are processed when the Hyper-V support lands. No functional change intended. Signed-off-by: Sean Christopherson Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/x86.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ee9d88f0e84c..f1e3a4ec53ba 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3383,6 +3383,9 @@ static void kvm_vcpu_flush_tlb_all(struct kvm_vcpu *vcpu) { ++vcpu->stat.tlb_flush; static_call(kvm_x86_flush_tlb_all)(vcpu); + + /* Flushing all ASIDs flushes the current ASID... */ + kvm_clear_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); } static void kvm_vcpu_flush_tlb_guest(struct kvm_vcpu *vcpu) @@ -10464,12 +10467,15 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_mmu_sync_roots(vcpu); if (kvm_check_request(KVM_REQ_LOAD_MMU_PGD, vcpu)) kvm_mmu_load_pgd(vcpu); - if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) { + + /* + * Note, the order matters here, as flushing "all" TLB entries + * also flushes the "current" TLB entries, i.e. servicing the + * flush "all" will clear any request to flush "current". + */ + if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) kvm_vcpu_flush_tlb_all(vcpu); - /* Flushing all ASIDs flushes the current ASID... */ - kvm_clear_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); - } kvm_service_local_tlb_flush_requests(vcpu); if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) { -- 2.37.3