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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 285F8C4332B for ; Sat, 16 Jan 2021 01:26:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10F8623A9C for ; Sat, 16 Jan 2021 01:26:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729272AbhAPB0t (ORCPT ); Fri, 15 Jan 2021 20:26:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:57304 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728207AbhAPB0q (ORCPT ); Fri, 15 Jan 2021 20:26:46 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1610760359; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=OgKrm1eUqKSfGn7bceu+w+8caqwlMsQwlQqrULX8q6w=; b=mtD+kkD8UO9uWv7cOM8yu1chHaje/GO3BvjGVG677fp3Umux44LwNyfD+g3zVSTwovTjdK 9YrNEK2TjdZq2f9ZBknVOAXtML9B26GmiJ2yxTaYnhj3Lgbnt/f/1Pw7eTqgNIat7ruF+w GWmTdqa16RRza+ZFeFPOhV/sPmvuz/g= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D853EACAD; Sat, 16 Jan 2021 01:25:58 +0000 (UTC) Message-ID: <0a32e141d8929f75025a0d9544a4552f2a916c5d.camel@suse.com> Subject: Re: [PATCH] kvm: tracing: Fix unmatched kvm_entry and kvm_exit events From: Dario Faggioli To: linux-kernel@vger.kernel.org Cc: Lorenzo Brescia , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org Date: Sat, 16 Jan 2021 02:25:57 +0100 In-Reply-To: <160873470698.11652.13483635328769030605.stgit@Wayrath> References: <160873470698.11652.13483635328769030605.stgit@Wayrath> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-Qzk5xTc+W0ATjFC4asLe" User-Agent: Evolution 3.38.3 (by Flathub.org) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-Qzk5xTc+W0ATjFC4asLe Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2020-12-23 at 14:45 +0000, Dario Faggioli wrote: > From: Lorenzo Brescia >=20 > On VMX, if we exit and then re-enter immediately without leaving > the vmx_vcpu_run() function, the kvm_entry event is not logged. > That means we will see one (or more) kvm_exit, without its (their) > corresponding kvm_entry, as shown here: >=20 > =C2=A0CPU-1979 [002] 89.871187: kvm_entry: vcpu 1 > =C2=A0CPU-1979 [002] 89.871218: kvm_exit:=C2=A0 reason MSR_WRITE > =C2=A0CPU-1979 [002] 89.871259: kvm_exit:=C2=A0 reason MSR_WRITE >=20 > It also seems possible for a kvm_entry event to be logged, but then > we leave vmx_vcpu_run() right away (if vmx->emulation_required is > true). In this case, we will have a spurious kvm_entry event in the > trace. >=20 Gentle ping... :-) Thanks and Regards --=20 Dario Faggioli, Ph.D http://about.me/dario.faggioli Virtualization Software Engineer SUSE Labs, SUSE https://www.suse.com/ ------------------------------------------------------------------- <> (Raistlin Majere) --=-Qzk5xTc+W0ATjFC4asLe Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEES5ssOj3Vhr0WPnOLFkJ4iaW4c+4FAmACQKUACgkQFkJ4iaW4 c+5RKQ//a6ToUu0sWhqEUEfvtvWB92cs7qxz5G8NtccK1p/E8X28l8pTBxT7W37G rH4hZ/0RKHFxlAxklRV4TFpNBHOQTTTCxPi2xmGachkQRbTRKrlldafgPUQH1SSO hMkDCwYWiR97W3FnhXnTxOjWpBpDifGLRh4/y3f+2AYvNWTmRaf5FmKsitGHAq/W MbNc6VASM+QoBIwJPaWbt/InvSOo5sX487fhbDixF1BDZR2ujVkCHvm/U+jp3fcs 8EwAxkOqQSiTmwge0fEhR6AEbTdUGqlE8Yx5jGN0gIbpRv2v5I8QfccicCPVH007 SIqlZIMEUvfMYzLZZATVg/gHeqs8p2FKgZ8YkIVmQ5rnwVhWvIyQOI4k+/LVVkYL NeYMibnMBje9YqeRlGLMYqSRQigIhaIA0OUibldVx/HB/dIXDUK1Xg14a8Mggud8 kQ1+jfsPHV7jnngxCD7Un2S/ZIT20PsrtSSB1PLOjzszJIwZRnSOU0wtmC2lQF0l hzcmlLRqq0md/5ZXdpJanLfG4QT/dqKmcrYYOfgOssdUH5c8b50EBVjPMwHI6rA/ vgCHLtN7k9sqfZMtC4SUTPN5QOFJJW4jbzOcAaDHaRvKcF5xv4YZKh7hcKDBGz/X JuuTzoyaSiYV4ASf/VCgwbQlkXgoIhw4LCpzhh+x2z4zrDhXrfQ= =L5Uz -----END PGP SIGNATURE----- --=-Qzk5xTc+W0ATjFC4asLe--