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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9ADC0C433EF for ; Tue, 26 Apr 2022 20:06:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CE1C56B0074; Tue, 26 Apr 2022 16:06:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C8F9A6B0075; Tue, 26 Apr 2022 16:06:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B57C56B0078; Tue, 26 Apr 2022 16:06:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id A805D6B0074 for ; Tue, 26 Apr 2022 16:06:46 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id 91A4E60BF0 for ; Tue, 26 Apr 2022 20:06:46 +0000 (UTC) X-FDA: 79400113212.27.17FD42D Received: from mail-vs1-f47.google.com (mail-vs1-f47.google.com [209.85.217.47]) by imf11.hostedemail.com (Postfix) with ESMTP id 20A1A40049 for ; Tue, 26 Apr 2022 20:06:43 +0000 (UTC) Received: by mail-vs1-f47.google.com with SMTP id y74so9770447vsy.7 for ; Tue, 26 Apr 2022 13:06:45 -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=OgWvl4x5HW7ZSGBHSfOaR0Afyso/w5Pk5vozFV5dfrY=; b=Ds9zo70XcwfEB3wOMBac72F+ntnGu3xzs/YqxOi1JBs7azT6/CA4xN2uHO7bso8bZG p3/rCJuf6xXdrX7y/RlV8nB3CUMe/xd6xOB34lD7Pq4Bk5gevNw4+OmG0wIIDuyyh0kw 39lBcfsyReRfUJOu07Hh+BDa+B5ERCSCOd1VtBmmpbaH8qQwmLXU0hv/rFT4y5nmWF0V W+0+aNmsNkte9HBib0h42/gMLGbMlKYZHYerI7WNGoUjq2Hi5UelSMmAvSr61hBH42Xj 04d3swY0liGEjKMgany06eQRp2x+yYeJepwstPQLTqNnrS+6cL3vhyu/2CwiCs8hU1N4 Fn8A== 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=OgWvl4x5HW7ZSGBHSfOaR0Afyso/w5Pk5vozFV5dfrY=; b=XavoblrPeAozAK19F7VeCHIlAC55sSBbe20SQC2bYpJlB4pHNFKt7XJGtOtWdEVbTZ IMKQEVz559HGxzSs7xZgOwSjqAFYhljYJUPYPamXpPvBuOww8JLWVyseJAfhBdtXVlhz 2kildmAqolg5N1tyxE3HXolKt5ibFqpZ9UB4GrbKpMWHxBVq8M1hMm21jCWHDpzfDtui V8oRw2ElZLA53B0hu5eRp6l5BHPm8RPlHFpII9JCDPpxbjV5QsYmi6U7Fh5ZLRpavFLn B8wh0WOAaxDCHyIC5Tyg9cTWPXolLuA37msLEwr9g2NotjnXnpOoHfMEi5tXvfIXc4Dj 4X1A== X-Gm-Message-State: AOAM533pAKzrDvwWPaZeM17idP6Hkaxp8DsBl+x5sdDppweGlJn0q1Me KbPAnVxU6jFYRpYwObFQPppvIjqv0AOpVGwQY5YB8w== X-Google-Smtp-Source: ABdhPJxTPOxaP2bqNQJLk4uv2KbCiWAHJ/WByIlTo0+huCaluMH7LfUbNMOq/QpsdrfoI4q4W6mr2Rkt6jmd6oN+hMc= X-Received: by 2002:a67:e3a1:0:b0:32c:eaad:ecea with SMTP id j1-20020a67e3a1000000b0032ceaadeceamr1188484vsm.35.1651003604954; Tue, 26 Apr 2022 13:06:44 -0700 (PDT) MIME-Version: 1.0 References: <20220425163451.3818838-1-juew@google.com> <8eceffc0-01e8-2a55-6eb9-b26faa9e3caf@intel.com> <02d9633ca83d41e8af410b1d36eb6a95@intel.com> In-Reply-To: <02d9633ca83d41e8af410b1d36eb6a95@intel.com> From: Jue Wang Date: Tue, 26 Apr 2022 13:06:33 -0700 Message-ID: Subject: Re: [RFC] Expose a memory poison detector ioctl to user space. To: "Luck, Tony" Cc: "Hansen, Dave" , Naoya Horiguchi , Dave Hansen , Jiaqi Yan , Greg Thelen , Mina Almasry , "linux-mm@kvack.org" , Sean Christopherson Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: ircunp4o5y7rtmjdkwmupfydo8ytk3op X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 20A1A40049 Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Ds9zo70X; spf=pass (imf11.hostedemail.com: domain of juew@google.com designates 209.85.217.47 as permitted sender) smtp.mailfrom=juew@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspam-User: X-HE-Tag: 1651003603-288350 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Apr 26, 2022 at 12:52 PM Luck, Tony wrote: > > One thing that would be relatively easy to do would be pre-allocate and pre-scan memory at guest creation: > > 1) Request to set up a guest with X GB memory > 2) Allocate X GB > 3) Zero it > 4) Scan for poison > 5) Map memory to guest and run the guest > > Should work with TDX (because you scan while host still has control/access to the pages). > > But this has issues if you have long-lived guests. Or want to overcommit memory so don't > really give a guest all the physical memory that it asks for. Thanks Tony. I agree this could be a starting point to get TDX / SEV-SNP guest memory scanned. It may still be much better than not scanning them. We need to follow up on a long term solution is needed for long running guest. > > -Tony