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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 CCD6AC433DB for ; Thu, 28 Jan 2021 18:50:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78D8E64E21 for ; Thu, 28 Jan 2021 18:50:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231461AbhA1St2 (ORCPT ); Thu, 28 Jan 2021 13:49:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232129AbhA1SqD (ORCPT ); Thu, 28 Jan 2021 13:46:03 -0500 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A33BC061793 for ; Thu, 28 Jan 2021 10:45:23 -0800 (PST) Received: by mail-lf1-x12b.google.com with SMTP id p21so8961075lfu.11 for ; Thu, 28 Jan 2021 10:45:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=+pbMkZm7NigUA8MDQfToYpV4bo7Pj4kIa3i69Hik+9g=; b=aStsaTkGQtmd53qvSTdCKXUSGqnrcwud0LUZyFv8opnKBS56BlvSbDOBb5+zqkFYlh Rva74RyIXoYc7zrbyNXSmIUOIxlBnRQjqoUIvBwAGt7zGxcQw0P7+43ur89zjIrM8hiz nfMmny46X/50PJEIlHu0lVF680aP1JeayXwzJ8YlHRSzOCLoVanUTgexg5UjYwTvrFtJ OQ+8kezrc3PDXz3jA3wsq7Z+49aZUBRPkZfF6yVnHsirwUudJLylzZDXkwyUA5YewFEc Mx71xllwmq6+vFLI0bMGz/p3IRciTyl20+yMkEyp/tC+cIyTv97na60p+iFsi6gQtmDi gWbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+pbMkZm7NigUA8MDQfToYpV4bo7Pj4kIa3i69Hik+9g=; b=RXDxKHGYIaujaOF/u7u4xYpE9z3V4LFG06+sFTXSaVLF3yk5nbaUQFXvjsPm63XSxa L5AqKxZZKlxhnchszX6qdG8u2aRReLYE6O1lac83XumfdDi5/l4K+udLo5HYI0e36Av9 WLxDX6edRWWawaAPebQOQ/1fQePgdGrfUGUnm77ng2RgoJ2ba21O7ButB8zQwn8H7Acd xbM8KykKNzsK5oRkz48Jq3EpWRNTippgPKkhhWcyCp/k6qEeB42GYtXMtMnqZvjQVBNR EbuHegzsaWp1knwCf7khoVah3Z33BioppLx64AqWhht6Qk7buHHokufPsKLhPDV48bOq yjgw== X-Gm-Message-State: AOAM532D5kUn5fIySON+NZzUfUveX7vONoiCtfx6j8RWASNwjSV+tuI0 mojjk7eQBAPuWJmOhsPjPXPRISmk03ubIw== X-Google-Smtp-Source: ABdhPJygFJo+zUkc16gywE7BeCr1FFcqBuLAgUixB5Hf/649/txu6fknLDev77aBPrVFdW8ThvV+Iw== X-Received: by 2002:a19:d07:: with SMTP id 7mr194761lfn.215.1611859521277; Thu, 28 Jan 2021 10:45:21 -0800 (PST) Received: from localhost.localdomain (37-145-186-126.broadband.corbina.ru. [37.145.186.126]) by smtp.gmail.com with ESMTPSA id k8sm1750508lfg.41.2021.01.28.10.45.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Jan 2021 10:45:20 -0800 (PST) From: Elena Afanasova To: kvm@vger.kernel.org Cc: stefanha@redhat.com, jag.raman@oracle.com, elena.ufimtseva@oracle.com, Elena Afanasova Subject: [RFC v2 4/4] KVM: enforce NR_IOBUS_DEVS limit if kmemcg is disabled Date: Thu, 28 Jan 2021 21:32:23 +0300 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org ioregionfd relies on kmemcg in order to limit the amount of kernel memory that userspace can consume. Enforce NR_IOBUS_DEVS hardcoded limit in case kmemcg is disabled. Signed-off-by: Elena Afanasova --- virt/kvm/kvm_main.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 096504a6cc62..74bedb7272e6 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4352,9 +4352,12 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, if (!bus) return -ENOMEM; - /* exclude ioeventfd which is limited by maximum fd */ - if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) - return -ENOSPC; + /* enforce hard limit if kmemcg is disabled and + * exclude ioeventfd which is limited by maximum fd + */ + if (!memcg_kmem_enabled()) + if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) + return -ENOSPC; new_bus = kmalloc(struct_size(bus, range, bus->dev_count + 1), GFP_KERNEL_ACCOUNT); -- 2.25.1