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=-12.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 8FDC6C433E2 for ; Sun, 6 Sep 2020 06:52:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 524852080A for ; Sun, 6 Sep 2020 06:52:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bBMF2qL2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726592AbgIFGwk (ORCPT ); Sun, 6 Sep 2020 02:52:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725283AbgIFGwk (ORCPT ); Sun, 6 Sep 2020 02:52:40 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCBC4C061573 for ; Sat, 5 Sep 2020 23:52:39 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id 31so6456804pgy.13 for ; Sat, 05 Sep 2020 23:52:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=I8rUO5c4QrQRi9NNPvOCt3d+iZWUjwi1tunN9Rub0tk=; b=bBMF2qL2q68MmK+glJEpZUPZMT5jo4AkJIZPACEdTgHHQYds5lYa0HzW4ZqHxulhek kg1UBfq/mFaLo4mOn+pW+Vr2Ub09QHqW8e0PkGGW7AXh2TpyTa73nKEBjxSt3a74KlNC 1C7BDNXH0LpF0QsHSLlfC3icvJnycMKJdKAerK94DBpDlsG0OV/dMQgJRn/DoCBQYdkp KrL3X4uQ8sCo0qSULOuCxy86q9BFzrAgFX3dvOLE74SF2yab+XAfBFLVnQ6SRnF8YZBm 5tUaZAPBx/Mz/D38G/C1aYXVHplqBczDkQnixhFqxwN2Ff/FOOGJSbaD7CVvyjbKRph2 x8+A== 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; bh=I8rUO5c4QrQRi9NNPvOCt3d+iZWUjwi1tunN9Rub0tk=; b=rU+t2rNcX6SomU1QS2Mv8DNuCqslsyeSX75ptvE2Bhr+uPPISEOukjEBeB5OLfttwo 2kWuEHbRs8Hd2KhcaHciy57z+colA3SvPKKRymSvZC0oTMzR7uEDPmv8au1F8IF8gb+Z MUUCEPmk0ZE84spugk4wFx1r4Tqgvs+zWwu1LPhWiQMTCu6jooKh6+h9pzFZAhLaLD7E fntL0w7dFJbt8eOaduO8K3M1LEGGL+xj7Tw/jJl+LmlbI6ydrX7F1j4Qh7YFWMyAgGZq JdbVI8mMhR9m9wevpdD7Zb4Ef0QC8Hc5Lwee3nfRosEtoDbQ4nNBW1DokoZGeCKUrNKi q13A== X-Gm-Message-State: AOAM532deJcDubaBwDeJrpTK7OTXDdefxd5pdIr/V67yxwteojaSXxE9 Avq5M8JoJwnq56Yzk0ZIzy4= X-Google-Smtp-Source: ABdhPJwEUgCBR4QoLI3A2rl1Ro4L22TGg8358epQwwM3mEnmQWCqsaTjXqpy9QwbeAFz1ke6Dlv9ug== X-Received: by 2002:aa7:83cf:: with SMTP id j15mr15147634pfn.251.1599375157754; Sat, 05 Sep 2020 23:52:37 -0700 (PDT) Received: from jordon-HP-15-Notebook-PC.domain.name ([122.171.54.54]) by smtp.gmail.com with ESMTPSA id n128sm9199947pga.5.2020.09.05.23.52.34 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 05 Sep 2020 23:52:36 -0700 (PDT) From: Souptick Joarder To: boris.ostrovsky@oracle.com, jgross@suse.com, sstabellini@kernel.org, david.vrabel@citrix.com Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, Souptick Joarder , John Hubbard Subject: [PATCH 1/2] xen/gntdev.c: Mark pages as dirty Date: Sun, 6 Sep 2020 12:21:53 +0530 Message-Id: <1599375114-32360-1-git-send-email-jrdr.linux@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There seems to be a bug in the original code when gntdev_get_page() is called with writeable=true then the page needs to be marked dirty before being put. To address this, a bool writeable is added in gnt_dev_copy_batch, set it in gntdev_grant_copy_seg() (and drop `writeable` argument to gntdev_get_page()) and then, based on batch->writeable, use set_page_dirty_lock(). Fixes: a4cdb556cae0 (xen/gntdev: add ioctl for grant copy) Suggested-by: Boris Ostrovsky Signed-off-by: Souptick Joarder Cc: John Hubbard Cc: Boris Ostrovsky Cc: Juergen Gross Cc: David Vrabel --- drivers/xen/gntdev.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 64a9025a..5e1411b 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -720,17 +720,18 @@ struct gntdev_copy_batch { s16 __user *status[GNTDEV_COPY_BATCH]; unsigned int nr_ops; unsigned int nr_pages; + bool writeable; }; static int gntdev_get_page(struct gntdev_copy_batch *batch, void __user *virt, - bool writeable, unsigned long *gfn) + unsigned long *gfn) { unsigned long addr = (unsigned long)virt; struct page *page; unsigned long xen_pfn; int ret; - ret = get_user_pages_fast(addr, 1, writeable ? FOLL_WRITE : 0, &page); + ret = get_user_pages_fast(addr, 1, batch->writeable ? FOLL_WRITE : 0, &page); if (ret < 0) return ret; @@ -746,9 +747,13 @@ static void gntdev_put_pages(struct gntdev_copy_batch *batch) { unsigned int i; - for (i = 0; i < batch->nr_pages; i++) + for (i = 0; i < batch->nr_pages; i++) { + if (batch->writeable && !PageDirty(batch->pages[i])) + set_page_dirty_lock(batch->pages[i]); put_page(batch->pages[i]); + } batch->nr_pages = 0; + batch->writeable = false; } static int gntdev_copy(struct gntdev_copy_batch *batch) @@ -837,8 +842,9 @@ static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch, virt = seg->source.virt + copied; off = (unsigned long)virt & ~XEN_PAGE_MASK; len = min(len, (size_t)XEN_PAGE_SIZE - off); + batch->writeable = false; - ret = gntdev_get_page(batch, virt, false, &gfn); + ret = gntdev_get_page(batch, virt, &gfn); if (ret < 0) return ret; @@ -856,8 +862,9 @@ static int gntdev_grant_copy_seg(struct gntdev_copy_batch *batch, virt = seg->dest.virt + copied; off = (unsigned long)virt & ~XEN_PAGE_MASK; len = min(len, (size_t)XEN_PAGE_SIZE - off); + batch->writeable = true; - ret = gntdev_get_page(batch, virt, true, &gfn); + ret = gntdev_get_page(batch, virt, &gfn); if (ret < 0) return ret; -- 1.9.1