From patchwork Wed Nov 29 13:55:26 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Wei W" X-Patchwork-Id: 10082343 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id F036160353 for ; Wed, 29 Nov 2017 14:16:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EA5AE298F3 for ; Wed, 29 Nov 2017 14:16:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DEC75298F7; Wed, 29 Nov 2017 14:16:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9286F298F3 for ; Wed, 29 Nov 2017 14:16:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932743AbdK2OQY (ORCPT ); Wed, 29 Nov 2017 09:16:24 -0500 Received: from mga05.intel.com ([192.55.52.43]:33488 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755093AbdK2OLu (ORCPT ); Wed, 29 Nov 2017 09:11:50 -0500 Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Nov 2017 06:11:50 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,473,1505804400"; d="scan'208";a="7221828" Received: from devel-ww.sh.intel.com ([10.239.48.110]) by FMSMGA003.fm.intel.com with ESMTP; 29 Nov 2017 06:11:46 -0800 From: Wei Wang To: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, akpm@linux-foundation.org, mawilcox@microsoft.com Cc: david@redhat.com, penguin-kernel@I-love.SAKURA.ne.jp, cornelia.huck@de.ibm.com, mgorman@techsingularity.net, aarcange@redhat.com, amit.shah@redhat.com, pbonzini@redhat.com, willy@infradead.org, wei.w.wang@intel.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu@aliyun.com, nilal@redhat.com, riel@redhat.com Subject: [PATCH v18 10/10] virtio-balloon: don't report free pages when page poisoning is enabled Date: Wed, 29 Nov 2017 21:55:26 +0800 Message-Id: <1511963726-34070-11-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1511963726-34070-1-git-send-email-wei.w.wang@intel.com> References: <1511963726-34070-1-git-send-email-wei.w.wang@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The guest free pages should not be discarded by the live migration thread when page poisoning is enabled with PAGE_POISONING_NO_SANITY=n, because skipping the transfer of such poisoned free pages will trigger false positive when new pages are allocated and checked on the destination. This patch skips the reporting of free pages in the above case. Reported-by: Michael S. Tsirkin Signed-off-by: Wei Wang Cc: Michal Hocko --- drivers/virtio/virtio_balloon.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 035bd3a..6ac4cff 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -652,7 +652,9 @@ static void report_free_page(struct work_struct *work) /* Start by sending the obtained cmd id to the host with an outbuf */ send_one_desc(vb, vb->free_page_vq, virt_to_phys(&vb->start_cmd_id), sizeof(uint32_t), false, true, false); - walk_free_mem_block(vb, 0, &virtio_balloon_send_free_pages); + if (!(page_poisoning_enabled() && + !IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY))) + walk_free_mem_block(vb, 0, &virtio_balloon_send_free_pages); /* * End by sending the stop id to the host with an outbuf. Use the * non-batching mode here to trigger a kick after adding the stop id.