From patchwork Wed Oct 21 16:37:44 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "lan,Tianyu" X-Patchwork-Id: 7458911 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id CA643BEEA4 for ; Wed, 21 Oct 2015 16:51:01 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 033DD20879 for ; Wed, 21 Oct 2015 16:51:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F263A20850 for ; Wed, 21 Oct 2015 16:50:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755934AbbJUQue (ORCPT ); Wed, 21 Oct 2015 12:50:34 -0400 Received: from mga02.intel.com ([134.134.136.20]:8199 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751575AbbJUQuc (ORCPT ); Wed, 21 Oct 2015 12:50:32 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 21 Oct 2015 09:50:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,712,1437462000"; d="scan'208";a="831883854" Received: from lantianyu-ws.sh.intel.com (HELO localhost) ([10.239.159.159]) by orsmga002.jf.intel.com with ESMTP; 21 Oct 2015 09:49:56 -0700 From: Lan Tianyu To: bhelgaas@google.com, carolyn.wyborny@intel.com, donald.c.skidmore@intel.com, eddie.dong@intel.com, nrupal.jani@intel.com, yang.z.zhang@intel.com, agraf@suse.de, kvm@vger.kernel.org, pbonzini@redhat.com, qemu-devel@nongnu.org, emil.s.tantilov@intel.com, intel-wired-lan@lists.osuosl.org, jeffrey.t.kirsher@intel.com, jesse.brandeburg@intel.com, john.ronciak@intel.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, matthew.vick@intel.com, mitch.a.williams@intel.com, netdev@vger.kernel.org, shannon.nelson@intel.com Cc: Lan Tianyu Subject: [RFC Patch 12/12] IXGBEVF: Track dma dirty pages Date: Thu, 22 Oct 2015 00:37:44 +0800 Message-Id: <1445445464-5056-13-git-send-email-tianyu.lan@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1445445464-5056-1-git-send-email-tianyu.lan@intel.com> References: <1445445464-5056-1-git-send-email-tianyu.lan@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Migration relies on tracking dirty page to migrate memory. Hardware can't automatically mark a page as dirty after DMA memory access. VF descriptor rings and data buffers are modified by hardware when receive and transmit data. To track such dirty memory manually, do dummy writes(read a byte and write it back) during receive and transmit data. Signed-off-by: Lan Tianyu --- drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index d22160f..ce7bd7a 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c @@ -414,6 +414,9 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector, if (!(eop_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD))) break; + /* write back status to mark page dirty */ + eop_desc->wb.status = eop_desc->wb.status; + /* clear next_to_watch to prevent false hangs */ tx_buffer->next_to_watch = NULL; tx_buffer->desc_num = 0; @@ -946,15 +949,17 @@ static struct sk_buff *ixgbevf_fetch_rx_buffer(struct ixgbevf_ring *rx_ring, { struct ixgbevf_rx_buffer *rx_buffer; struct page *page; + u8 *page_addr; rx_buffer = &rx_ring->rx_buffer_info[rx_ring->next_to_clean]; page = rx_buffer->page; prefetchw(page); - if (likely(!skb)) { - void *page_addr = page_address(page) + - rx_buffer->page_offset; + /* Mark page dirty */ + page_addr = page_address(page) + rx_buffer->page_offset; + *page_addr = *page_addr; + if (likely(!skb)) { /* prefetch first cache line of first page */ prefetch(page_addr); #if L1_CACHE_BYTES < 128 @@ -1032,6 +1037,9 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector, if (!ixgbevf_test_staterr(rx_desc, IXGBE_RXD_STAT_DD)) break; + /* Write back status to mark page dirty */ + rx_desc->wb.upper.status_error = rx_desc->wb.upper.status_error; + /* This memory barrier is needed to keep us from reading * any other fields out of the rx_desc until we know the * RXD_STAT_DD bit is set