From patchwork Sun Feb 21 12:04:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elena Afanasova X-Patchwork-Id: 12097303 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=-15.8 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 6CD8FC433E0 for ; Sun, 21 Feb 2021 12:12:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44BCE64F00 for ; Sun, 21 Feb 2021 12:12:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229974AbhBUMMM (ORCPT ); Sun, 21 Feb 2021 07:12:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229925AbhBUMMH (ORCPT ); Sun, 21 Feb 2021 07:12:07 -0500 Received: from mail-lj1-x22d.google.com (mail-lj1-x22d.google.com [IPv6:2a00:1450:4864:20::22d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B07D0C06178C for ; Sun, 21 Feb 2021 04:11:26 -0800 (PST) Received: by mail-lj1-x22d.google.com with SMTP id a17so47264940ljq.2 for ; Sun, 21 Feb 2021 04:11:26 -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=6BaYeStx5XlEI2H6fREV0PGgKmNTuolmOOj8Wnxngjs=; b=QGUUUqwYGj3Bl/lr90Oe9KVytxhiEOK0IuBBCOV9l8LowRPufr5Q1TSW1mhdPCzXYX 7BJGIOm78YenXRt/KoPDcC3kvQH7WDjFMLGcCIkfaQTDRKdFM9Btfha5YnnDx71gtX8v g1a9d+N5dRoYIB8pmtf4e+Y5FokO2hil6Q67hd5syBEwQ3kAdmacR4f+p2zfRA7Ac8Bn y32Idt0CCDrhKZrmyMQ8OK4Bvz7bxMMogHUMafNbk2Jno46LNYx/KbLmQFPdnB9YC3+J Y3b7zrBEng2F4TKcSr51V1ddyeKR1sfvjaKwOmbi3JCyCZkO16/yhSF7Jb61SYpXUlVr v5rA== 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=6BaYeStx5XlEI2H6fREV0PGgKmNTuolmOOj8Wnxngjs=; b=cLo0WNCEOXy9QFCpBaAKqCNT/A8y5MkNW5QKJpObjOnzHxd6w06t5bMPkghHytmEQT Q6MUt5HuVCcXDysmyL2wq9MgGL9LsywOp7hPnq8Uo5EFPUjjIylmwAbi3V6XGk8MP2AI P+bTXJphpk6mQQeEtJidAHSUq73J//PzbYZ6kzZHJIuG6FOiGgl1LMAb6n75zBadXULT sxjWdVq5sg1FZEGjDVaA7GlJgSRcGwhsoWqcJKC8OqnW9NrHU0iVEA3ODCWEqmnt6Ox4 MBvNKwnFh3+w2qkyPw4dmzx3treRfaE093kn39uA9zXoHKVxAX9ETX9ddYgcWf9gugoM DzKw== X-Gm-Message-State: AOAM533rCz6LHoFffRyo5uhZ/nhOAVqObhY9O725W67IwZtWFlGpr6TN qQgLCBD0hsWG0IWnx6db4jqUXnCeMt7NRfnQ X-Google-Smtp-Source: ABdhPJxru09ZwV8MbCjkpcHfT/qCx8SjEGcn+/3yVxYO9XyvcHoJpoqW2hvMt3h6EXnCoHwSuj0Exw== X-Received: by 2002:a2e:9b5a:: with SMTP id o26mr3274555ljj.6.1613909484968; Sun, 21 Feb 2021 04:11:24 -0800 (PST) Received: from localhost.localdomain (37-145-186-126.broadband.corbina.ru. [37.145.186.126]) by smtp.gmail.com with ESMTPSA id q6sm1547715lfn.23.2021.02.21.04.11.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 21 Feb 2021 04:11:24 -0800 (PST) From: Elena Afanasova To: kvm@vger.kernel.org Cc: stefanha@redhat.com, jag.raman@oracle.com, elena.ufimtseva@oracle.com, pbonzini@redhat.com, jasowang@redhat.com, mst@redhat.com, cohuck@redhat.com, john.levon@nutanix.com, Elena Afanasova Subject: [RFC v3 5/5] KVM: enforce NR_IOBUS_DEVS limit if kmemcg is disabled Date: Sun, 21 Feb 2021 15:04:41 +0300 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 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 df387857f51f..99a828153afd 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4320,9 +4320,12 @@ 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);