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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 F20CCC32750 for ; Tue, 13 Aug 2019 08:44:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D129720679 for ; Tue, 13 Aug 2019 08:44:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727303AbfHMIod (ORCPT ); Tue, 13 Aug 2019 04:44:33 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:36562 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725909AbfHMIoc (ORCPT ); Tue, 13 Aug 2019 04:44:32 -0400 Received: by mail-wr1-f65.google.com with SMTP id r3so13234727wrt.3 for ; Tue, 13 Aug 2019 01:44:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=blKE7hBPEaF3XcD8274I5hmyBZ0ZERzbpulCfit8yl4=; b=fw+BUVmVAOa37fDeyLWpYVWNQHXKuWXjKW5ZkXX2m8ab+rGgCkZYqLemhLBODraLsT fScyO9Op+/YYKfG2HojD1BzASZZQzIv/I/d3yIKWNjtv+ie6YWRlq0Mr9D0XxWowH77P 8UAr/qM+eAuOzHMWxpL7LxJnY7BtHAAFZqqTHLL7xxUTeS3EVm+KlKghMiVx2Pf+A9tr xa2+NrCFclpQ/6Ou0pCRpGyAjYqg4YymHDGhWS6OOn4AfZ+uf7h9lmMKaiIUzVZOXoFS J8ObzGaXos7dPC+hxvy27GnJ7MYRl5IIP6u1T1fljuqI3helV7+TLOizv/dJWP4ZSeXM podg== X-Gm-Message-State: APjAAAWWbWVuQku+qkZ8Y71Sde0GXWWepMzG9rKamdLPA3Tcq2xf0YEY L94G9OjAfBfyENdrY1PBlVsBjQ== X-Google-Smtp-Source: APXvYqw492WjaEpNzhoTXs/Gd2KelQnitfzJEsecNo1teLr2zcjaHoX7vjpPsoanUMoKR8v6ysgEKw== X-Received: by 2002:a5d:490a:: with SMTP id x10mr42031164wrq.152.1565685870989; Tue, 13 Aug 2019 01:44:30 -0700 (PDT) Received: from [192.168.10.150] ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id o126sm1401625wmo.1.2019.08.13.01.44.29 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Tue, 13 Aug 2019 01:44:30 -0700 (PDT) Subject: Re: [RFC PATCH v6 02/92] kvm: introspection: add basic ioctls (hook/unhook) To: =?UTF-8?Q?Adalbert_Laz=c4=83r?= , kvm@vger.kernel.org Cc: linux-mm@kvack.org, virtualization@lists.linux-foundation.org, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Konrad Rzeszutek Wilk , Tamas K Lengyel , Mathieu Tarral , =?UTF-8?Q?Samuel_Laur=c3=a9n?= , Patrick Colp , Jan Kiszka , Stefan Hajnoczi , Weijiang Yang , Yu C Zhang , =?UTF-8?Q?Mihai_Don=c8=9bu?= , =?UTF-8?Q?Mircea_C=c3=aerjaliu?= References: <20190809160047.8319-1-alazar@bitdefender.com> <20190809160047.8319-3-alazar@bitdefender.com> From: Paolo Bonzini Openpgp: preference=signencrypt Message-ID: <58808ef0-57b1-47ac-a115-e1dd64a15b0a@redhat.com> Date: Tue, 13 Aug 2019 10:44:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190809160047.8319-3-alazar@bitdefender.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 09/08/19 17:59, Adalbert Lazăr wrote: > +static int kvmi_recv(void *arg) > +{ > + struct kvmi *ikvm = arg; > + > + kvmi_info(ikvm, "Hooking VM\n"); > + > + while (kvmi_msg_process(ikvm)) > + ; > + > + kvmi_info(ikvm, "Unhooking VM\n"); > + > + kvmi_end_introspection(ikvm); > + > + return 0; > +} > + Rename this to kvmi_recv_thread instead, please. > + > + /* > + * Make sure all the KVM/KVMI structures are linked and no pointer > + * is read as NULL after the reference count has been set. > + */ > + smp_mb__before_atomic(); This is an smp_wmb(), not an smp_mb__before_atomic(). Add a comment that it pairs with the refcount_inc_not_zero in kvmi_get. > + refcount_set(&kvm->kvmi_ref, 1); > + > @@ -57,8 +183,27 @@ void kvmi_destroy_vm(struct kvm *kvm) > if (!ikvm) > return; > > + /* trigger socket shutdown - kvmi_recv() will start shutdown process */ > + kvmi_sock_shutdown(ikvm); > + > kvmi_put(kvm); > > /* wait for introspection resources to be released */ > wait_for_completion_killable(&kvm->kvmi_completed); > } > + This addition means that kvmi_destroy_vm should have called kvmi_end_introspection instead. In patch 1, kvmi_end_introspection should have been just kvmi_put, now this patch can add kvmi_sock_shutdown. Paolo