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 EC511C636D4 for ; Mon, 30 Jan 2023 18:41:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235170AbjA3Slq (ORCPT ); Mon, 30 Jan 2023 13:41:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234744AbjA3Sld (ORCPT ); Mon, 30 Jan 2023 13:41:33 -0500 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 946EF14235 for ; Mon, 30 Jan 2023 10:41:24 -0800 (PST) Received: by mail-pj1-x1035.google.com with SMTP id nm12-20020a17090b19cc00b0022c2155cc0bso11985908pjb.4 for ; Mon, 30 Jan 2023 10:41:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=pMghoIK65PM21gBRzt5p+NP2NarTeHArU4fe9Np3EMM=; b=RgUboakthKgaIXLyoWrNSG2Qv+J4K4JVomfyOYRELSvc5h9W2XdiM6x29P9pBoUF4u FuefKa87xQLhJqo174kgnXIhDIBqKpjuHKSEm8GQY1vsujPrMdEr+oih2XdcLeMBoHSN /DzRzjUdxrmeEF9SsiIOWIRP+i2fwXSPrONAY2rfB6JAKM4u5SuPV2Gnle5+hxGhdIyg CeEWU+kqvAPuLpF1NWpgd3T9Zs6+kh1pKBDvywm1ku+M1m+2cd/SAGUfGpjjDj3k0z/a keybctHpc1Mf6LAfVm2XgrSmRowAknVTrXv8TT+F+GAxGNOFQtv9Jx63nHffhwPIrSSa +80g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=pMghoIK65PM21gBRzt5p+NP2NarTeHArU4fe9Np3EMM=; b=PQ/tHv7TlcmjjK0s16nCmuVx340itOOQlbXM9kIedV3GL6eHneyTeVH50uzWnng0lP kVjPRaYifnE7hsQAqY3gPlK4WbD8Am7AdY/GjYisrsPJlq4tQj6p2BNeUAyn23kSxsDM XCMQohXrAFbFC6ACofWS+dMEWbFmVULH1NeSixkzqhDE6c6sUTaAbG0JbOzu+/EjoZVm H6iaSll7KpNCCrWBazAiY2T+MOHKr5Iq6RV72n9Mk6b/MMZlc7eMEha5StxDRfqh8zBe kqEfGkfEHsfrNNo2ndwsx2fgzTqp++8vSe6m5BT1aaq1YEczy579p+Eq483vPz7GohlA HOrw== X-Gm-Message-State: AO0yUKWh4ttdwE7dcwQkt4vWvu+v8JDwrloRPPudUECY+PtyvohTBvzp So+0e4JOpTxv9papTRpaiQ/sLQ== X-Google-Smtp-Source: AK7set93e70967TnM9xQUAufViAl7AKeAOmHVIVJKjWAzb0Q/qRJgbxj/GDWc5BGkhuUv0igh5SXqQ== X-Received: by 2002:a17:902:d70a:b0:193:256d:8afe with SMTP id w10-20020a170902d70a00b00193256d8afemr873089ply.2.1675104083967; Mon, 30 Jan 2023 10:41:23 -0800 (PST) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id m3-20020a170902c44300b00186f0f59c85sm8141000plm.235.2023.01.30.10.41.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Jan 2023 10:41:23 -0800 (PST) Date: Mon, 30 Jan 2023 18:41:19 +0000 From: Sean Christopherson To: Maxim Levitsky Cc: kvm@vger.kernel.org, Sandipan Das , Paolo Bonzini , Jim Mattson , Peter Zijlstra , Dave Hansen , Borislav Petkov , Pawan Gupta , Thomas Gleixner , Ingo Molnar , Josh Poimboeuf , Daniel Sneddon , Jiaxi Chen , Babu Moger , linux-kernel@vger.kernel.org, Jing Liu , Wyes Karny , x86@kernel.org, "H. Peter Anvin" Subject: Re: [PATCH v2 03/11] KVM: nSVM: explicitly raise KVM_REQ_EVENT on nested VM exit if L1 doesn't intercept interrupts Message-ID: References: <20221129193717.513824-1-mlevitsk@redhat.com> <20221129193717.513824-4-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 28, 2023, Sean Christopherson wrote: > > + * If the L2 doesn't intercept interrupts, then > > + * (even if the L2 does use virtual interrupt masking), > > KVM uses "L2" to refer to the thing running at L2. I think what you are referring > to here is vmcb12? And that's controlled by L1. > > > + * KVM will use the vmcb02's V_INTR to detect interrupt window. > > s/the vmcb02/vmcb02 > > Which of the V_INTR fields does this refer to? Oooh, you're saying the KVM injects > a virtual interrupt into L2 using vmcb02 in order to determine when L2 has IRQs > enabled. > > Why does KVM do that? Why not pend the actual IRQ directly? Duh, because KVM needs to gain control in if there are multiple pending events.