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 31FCEC6FA8A for ; Fri, 9 Sep 2022 12:08:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229906AbiIIMIu (ORCPT ); Fri, 9 Sep 2022 08:08:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231138AbiIIMIk (ORCPT ); Fri, 9 Sep 2022 08:08:40 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B84DA13813D for ; Fri, 9 Sep 2022 05:08:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1662725317; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0zXr68Ku17TqRx7WZIlisO7PY+izsxHqFvN1+7uz8BY=; b=QMZ2FiByoBlj+vPsnsfERownjLq/39NFmKSRsqAmsObsTIDqvpXUHwFZBZxzCCetYiq31o FHCpCFHSc54ueUIoeO+6Gu1Wjqmtu4Jw540km1EN0zoQp3vNaKXKbrmDHkhMe+EPA+3ZTX dpPw8QfDTRD1vMWVBYI2mcNp7X11k5M= Received: from mail-io1-f71.google.com (mail-io1-f71.google.com [209.85.166.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-209-9XjLa4tqMDuo8qnebtNdpQ-1; Fri, 09 Sep 2022 08:08:35 -0400 X-MC-Unique: 9XjLa4tqMDuo8qnebtNdpQ-1 Received: by mail-io1-f71.google.com with SMTP id s2-20020a6bdc02000000b006a0cb10e1e8so405722ioc.14 for ; Fri, 09 Sep 2022 05:08:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:organization:references :in-reply-to:message-id:subject:cc:to:from:date:x-gm-message-state :from:to:cc:subject:date; bh=0zXr68Ku17TqRx7WZIlisO7PY+izsxHqFvN1+7uz8BY=; b=toMYLhxlGmtdGFrZm7BmDIo8niTFzvw/G1DpsQaJ8aC3VMMbbgdYjHgX49dMaVf5k0 gf9ASAVEf62w2+9WrUVx5mGQji0MG/k2khGA/MBIrhI6qjG2rwbsh6jSjBVHiYyr1Cdr FxV0mjQWQL1N+PQb4b31wY0dwqAE2fkefFtZZITWSL4N+/7x3akzo4itheKs3ckxp2CT w/hCWGsFt5LXMQ3tWuHS8rG5dw/SVeYSqEB8hqthHsTQ1h0cIgyaMmQnL0mlTQmNGyAb 97WT64JksvXxX5CY5wh3ELsiWHyylXcQLfu869NRS449kCYTA8wUkyCBsFhpGa+8ExxY kSwA== X-Gm-Message-State: ACgBeo2rc9FYKhsXhAYznaQ3nwMp1rhP5JzpyZUgfIjDUYITihufgRIo 3hBFWeai773T6IfHxOUESoayTuqmgjlkpWyq2nfzlZweKgUbFDVWz2Zqce4EM4dZXr7ip/Y7fwx 0R1YWAqMaTg3c X-Received: by 2002:a05:6602:1691:b0:68d:8e03:197b with SMTP id s17-20020a056602169100b0068d8e03197bmr6694183iow.190.1662725314162; Fri, 09 Sep 2022 05:08:34 -0700 (PDT) X-Google-Smtp-Source: AA6agR5iSRx1+fKzoqaDdK1SGGLBKpq8PLWfkyRCyK8z6gMVXMYQAnQZDmTYSNyT4G7AZUQrY+aZ8g== X-Received: by 2002:a05:6602:1691:b0:68d:8e03:197b with SMTP id s17-20020a056602169100b0068d8e03197bmr6694175iow.190.1662725313935; Fri, 09 Sep 2022 05:08:33 -0700 (PDT) Received: from redhat.com ([38.15.36.239]) by smtp.gmail.com with ESMTPSA id g15-20020a05663810ef00b00358422fcc7bsm126205jae.120.2022.09.09.05.08.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Sep 2022 05:08:33 -0700 (PDT) Date: Fri, 9 Sep 2022 06:08:32 -0600 From: Alex Williamson To: Linus Torvalds Cc: John Hubbard , David Hildenbrand , Andrew Morton , "kvm@vger.kernel.org" , linux-kernel@vger.kernel.org, Jason Gunthorpe Subject: Re: [GIT PULL] VFIO fix for v6.0-rc5 Message-ID: <20220909060832.17f6607f.alex.williamson@redhat.com> In-Reply-To: References: <20220909045225.3a572a57.alex.williamson@redhat.com> Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, 9 Sep 2022 07:53:17 -0400 Linus Torvalds wrote: > On Fri, Sep 9, 2022 at 6:52 AM Alex Williamson > wrote: > > > > VFIO fix for v6.0-rc5 > > > > - Fix zero page refcount leak (Alex Williamson) > > Ugh. This is disgusting. > > Don't get me wrong - I've pulled this, but I think there's some deeper > problem that made this patch required. > > Why is pin_user_pages_remote() taking a reference to a reserved page? > Maybe it just shouldn't (and then obviously we should fix the unpin > case to match too). > > Adding a few GUP people to the participants for comments. > > Anybody? Yes, David is working on allocating pages rather than pinning the zero page, however that's going to have some user visible locked memory accounting changes. This isn't the long term solution, it's only meant to close the shared zero page refcount holes we have currently. Thanks, Alex