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=-3.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 C75CFC4707D for ; Fri, 21 May 2021 19:22:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AFDD613D8 for ; Fri, 21 May 2021 19:22:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238465AbhEUTX4 (ORCPT ); Fri, 21 May 2021 15:23:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232789AbhEUTXz (ORCPT ); Fri, 21 May 2021 15:23:55 -0400 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD44BC061574 for ; Fri, 21 May 2021 12:22:31 -0700 (PDT) Received: by mail-pf1-x434.google.com with SMTP id d78so14751922pfd.10 for ; Fri, 21 May 2021 12:22:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HPitddRtg4/TXAC9F1uqaZjw01XMepc1KCiYJ28+nDk=; b=ezJ8H9SUYXgH1GqKIcsPsudxq6Mot+Y+nNDPRMNovXmkJw2dhvXGuaagsK6KQMmcKX itZAdKrG8taKmzNFyf14KliztyuFJPwVrPNFJ+QcZlD1V6fQwF0mtNIkPFn9voyJtNo2 bldvnZNko7OMgToPmvzC3QD10o3RzlkJtD0VML7KSIU4WEkKZXLs6RtUgSuRtydAufbo vcX/aXld3wlxeMVy0preZBOP9km+6qpihr1KJRmwn10+69R5QnIMZfa+3VEH2CnKg8az 9l1II+cvdEzT90cEt+7V+WrpAsCXww8f/p4+JurcMfZhvunUSF9Hkw8gK6zNANVCINu2 +Z/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=HPitddRtg4/TXAC9F1uqaZjw01XMepc1KCiYJ28+nDk=; b=g+YN5O5G2hg/Gzrb8HgtgqZTm84WtTvX+Oi/BBLKoSrvSC7+kuVIJGolVfOM7tRWze 9SYS3Nbwy3tMQ0m2zkXaYrU9bYKwLxn0jQxAxluzjoeDQN0kQplpmT7gF0xRHpRFHqo5 ni0kcDl+YXu6secCcFEZFn+aAj9/GTMmhDijq9oPTznJgAohzfOxLDPM5YGQMjTLye+F o2RFS1JsQ4v03cd6n6OaUkA4BEki312nj8KhXWoe5gCUpAx5+4BYSJrYuFRan+NWrm2Y RZMKEAQKf99YeUG1EJVa1OxeCuDY6tQJVy30gunGmUt8v0SbbNxMXhK4Pibc2Yh7Trmy zwpg== X-Gm-Message-State: AOAM530uLd+sCWnoLsmmknbh4z0wfflgSxVD6HCVVBhMETtFDaIgoyRP BaCJrsLK26E2vBqQJYHB7SoC+niwO9b4bCatgJnRQQ== X-Google-Smtp-Source: ABdhPJyX5PWO/h7plHMPPKsl6NclubUVV3LC5h40BWnkvE+LAwFsiOA1pCdLxmYfSy/gbpx/RuMB/HgNauWu7CBTzd8= X-Received: by 2002:a63:521a:: with SMTP id g26mr240971pgb.279.1621624951373; Fri, 21 May 2021 12:22:31 -0700 (PDT) MIME-Version: 1.0 References: <20210518000957.257869-1-sathyanarayanan.kuppuswamy@linux.intel.com> <4fc32900-412d-fa10-520e-afa6caade33e@intel.com> <81c0f447-44b8-c2b6-ce41-a39ec0a1832b@linux.intel.com> In-Reply-To: <81c0f447-44b8-c2b6-ce41-a39ec0a1832b@linux.intel.com> From: Dan Williams Date: Fri, 21 May 2021 12:22:21 -0700 Message-ID: Subject: Re: [RFC v2-fix 1/1] x86/traps: Add #VE support for TDX guest To: Andi Kleen Cc: Dave Hansen , Kuppuswamy Sathyanarayanan , Peter Zijlstra , Andy Lutomirski , Tony Luck , Kirill Shutemov , Kuppuswamy Sathyanarayanan , Raj Ashok , Sean Christopherson , Linux Kernel Mailing List , Sean Christopherson Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 18, 2021 at 8:45 AM Andi Kleen wrote: > > > On 5/18/2021 8:11 AM, Dave Hansen wrote: > > On 5/17/21 5:09 PM, Kuppuswamy Sathyanarayanan wrote: > >> After TDGETVEINFO #VE could happen in theory (e.g. through an NMI), > >> although we don't expect it to happen because we don't expect NMIs to > >> trigger #VEs. Another case where they could happen is if the #VE > >> exception panics, but in this case there are no guarantees on anything > >> anyways. > > This implies: "we do not expect any NMI to do MMIO". Is that true? Why? > > Only drivers that are not supported in TDX anyways could do it (mainly > watchdog drivers) What about apei_{read,write}() for ACPI error handling? Those are called in NMI to do MMIO accesses. It's not just watchdog drivers.