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 A1803C4332F for ; Wed, 23 Mar 2022 20:05:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244457AbiCWUHN (ORCPT ); Wed, 23 Mar 2022 16:07:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242564AbiCWUHL (ORCPT ); Wed, 23 Mar 2022 16:07:11 -0400 Received: from mail-yw1-x1130.google.com (mail-yw1-x1130.google.com [IPv6:2607:f8b0:4864:20::1130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7E1C89CEC for ; Wed, 23 Mar 2022 13:05:39 -0700 (PDT) Received: by mail-yw1-x1130.google.com with SMTP id 00721157ae682-2db2add4516so30342707b3.1 for ; Wed, 23 Mar 2022 13:05:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=0ltQEm4jkJpPFO26laIPZcGY83DKyfBZ1sw0JUywVss=; b=Yuz2n+O88bMGFiLvP9JQxndEu9C7Bjz6BlwPzjdaGBLhQqxtKjxKwgQzPGtuW6RBpA fLSqBttEmGFiP58M7lAc+Cbl+gPbR/8iiTR/B8SuFYIXOxo3I11NNt8XN5PqBDwtvUSI TBEiBrieiwW1BfhbgQOc+eWIJfqUk6hlDxl+FxNVQjPTFAcqN7aGFtn82h5SOCBwTmyk B5EcSifU3q45VDJG0gz7lGIgg9C4z+Wk24+xgjoCChJPqnHmECF8iMbDGmLCKGHN4ty1 eWXHa5DjNcpfK2fCwYGIA8ioxzhGm33Vz1l4GcXlZz6hpdIwWMeNSxtRD+g1SVfrMQNt DTyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=0ltQEm4jkJpPFO26laIPZcGY83DKyfBZ1sw0JUywVss=; b=2/6DlPAusMXVGCPFLBGlxTLck7oDcixmDhqSwcv01yrRGCCfCFDBxycDPdOIwbFK7v TDGDOoelhg/7UuX7n+zBwWiVquNH+PgPF9HJiYymGnOX9DrLYLH+LnsXeRXldDDjn4sd vG/EYlnatxSQLNo3Y4sMRa5g2NjD5wZyw0qylib71uDlHQjDmwgGcaM+scj6gVqLktB/ /qVe/oJMSSbXEji6XVAPzoNifo1eexjvhtQFgGXy7Pl6jnsGm/FBttganFD1+kSTAG0t SzOYnZqwYnxGZd2u+zZ31EYNmUv9EGbqVtpnMNfSQPgpdujjLteWvzNNpZxdsy3XczQT I0Ww== X-Gm-Message-State: AOAM533g11EqwTUW+05gZc7VEDC0/krUswobRwPU2PalAc/es3km+rco MgL0i+gLZIH/6Ygjo0H7ChX0AwsOqHwjB7l6Bzry6Q== X-Google-Smtp-Source: ABdhPJxDiIpzZ7WTx+jmKbHOAdv97rA0H0HYvVB8Owy+/SsU5Pne5Z9Fdnds0uwjTSiQ39wWWyqxQEfiZ+2F2Ldkyt0= X-Received: by 2002:a0d:e80e:0:b0:2e5:ba68:80bc with SMTP id r14-20020a0de80e000000b002e5ba6880bcmr1771295ywe.350.1648065938422; Wed, 23 Mar 2022 13:05:38 -0700 (PDT) MIME-Version: 1.0 References: <20220323175552.GG1964605@ls.amr.corp.intel.com> In-Reply-To: <20220323175552.GG1964605@ls.amr.corp.intel.com> From: Erdem Aktas Date: Wed, 23 Mar 2022 13:05:27 -0700 Message-ID: Subject: Re: [RFC PATCH v5 064/104] KVM: TDX: Implement TDX vcpu enter/exit path To: Isaku Yamahata Cc: "Yamahata, Isaku" , "open list:KERNEL VIRTUAL MACHINE (KVM)" , open list , Paolo Bonzini , Jim Mattson , Connor Kuehl , Sean Christopherson Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 23, 2022 at 10:55 AM Isaku Yamahata wrote: > > On Tue, Mar 22, 2022 at 10:28:42AM -0700, > Erdem Aktas wrote: > > > On Fri, Mar 4, 2022 at 11:50 AM wrote: > > > @@ -509,6 +512,37 @@ void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) > > > vcpu->kvm->vm_bugged = true; > > > } > > > > > > +u64 __tdx_vcpu_run(hpa_t tdvpr, void *regs, u32 regs_mask); > > > + > > > +static noinstr void tdx_vcpu_enter_exit(struct kvm_vcpu *vcpu, > > > + struct vcpu_tdx *tdx) > > > +{ > > > + guest_enter_irqoff(); > > > + tdx->exit_reason.full = __tdx_vcpu_run(tdx->tdvpr.pa, vcpu->arch.regs, 0); > > > + guest_exit_irqoff(); > > > +} > > > + > > > +fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu) > > > +{ > > > + struct vcpu_tdx *tdx = to_tdx(vcpu); > > > + > > > + if (unlikely(vcpu->kvm->vm_bugged)) { > > > + tdx->exit_reason.full = TDX_NON_RECOVERABLE_VCPU; > > > + return EXIT_FASTPATH_NONE; > > > + } > > > + > > > + trace_kvm_entry(vcpu); > > > + > > > + tdx_vcpu_enter_exit(vcpu, tdx); > > > + > > > + vcpu->arch.regs_avail &= ~VMX_REGS_LAZY_LOAD_SET; > > > + trace_kvm_exit(vcpu, KVM_ISA_VMX); > > > + > > > + if (tdx->exit_reason.error || tdx->exit_reason.non_recoverable) > > > + return EXIT_FASTPATH_NONE; > > > > Looks like the above if statement has no effect. Just checking if this > > is intentional. > > I'm not sure if I get your point. tdx->exit_reason is updated by the above > tdx_cpu_enter_exit(). So it makes sense to check .error or .non_recoverable. > -- > Isaku Yamahata What I mean is, if there is an error, it returns EXIT_FASTPATH_NONE but if there is no error, it still returns EXIT_FASTPATH_NONE. The code is like below, the if-statement might be there as a placeholder to check errors but it has no impact on what is returned from this function. if (tdx->exit_reason.error || tdx->exit_reason.non_recoverable) return EXIT_FASTPATH_NONE; return EXIT_FASTPATH_NONE;