Received: by 2002:a05:6359:c8b:b0:c7:702f:21d4 with SMTP id go11csp574381rwb; Thu, 6 Oct 2022 01:07:19 -0700 (PDT) X-Google-Smtp-Source: AMsMyM7LbaLq2cCPzjf9ohDyszX8LPDbkNKaN5l7+B2/7w6+iBac7o7eeTgcPsqhkMVyw1tOd3rJ X-Received: by 2002:a63:6302:0:b0:458:85e:9e69 with SMTP id x2-20020a636302000000b00458085e9e69mr3330593pgb.165.1665043639708; Thu, 06 Oct 2022 01:07:19 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1665043639; cv=none; d=google.com; s=arc-20160816; b=P0wQV7/ypLtBMv1oO2PpYvVSO9bCB1vzxa4r3VPuWYS0OXUbcH66vUwpBGqwgkXzAY FGSQRID+m8+wBIxxHOqHM/E2oGIp8SircXOraBNqSaCJrruleSejoDHV1zdhBzZ/mZKh RAASaxCTh17i6naUTn8G/AXzTWkMa0M92jnYUdhI0R5btkbksZncQC4weDUEbPHYJOUJ a2kghi1l5IVDpSXo4hgXp8tomR3Sqjtg5/I8A/rM6778o0j9b67ye6d6oZVw3bmJuusm BdkK71WgiDed3rewds5uLJNr8Wdi/GtVFbsX9A33gI8i9BJPyZ7sD+cqx1p/RtxLxbxE 6fHQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:in-reply-to:from :references:cc:to:content-language:subject:user-agent:mime-version :date:message-id:dkim-signature; bh=0dtKZhkDgaoTTpO0pEO0vifhDrrgR+WBWj56fb3zUfQ=; b=hV+vI6ea3s9oxseeAtxAMS5oSldpyoDSs7vFti8U1N6lIecMr491tkNkKEYbOTzE4c MtGLhwdQanO8TRs3CyOMtMlwFtiAYJgqcDAJInPCh9SwIJpAndchb/M5myrnUMP6sIlQ 8GLQDoaSkrPFdTDDiIcFZmGmfkB/XKoQpWRFsCuKB5YjPfhyZMd/Cr6BvknXUS9N6gH4 znF10r5cYc1JqcqB4oOWAFiQUBdP5Ln5GcD8hyf4mTqiptxGRSeO1vG8l5LHDeRWYtPM H78rRnTY/VPXN9uJvLWM6aSSVwsoVZP0QBUYPiMR7/J1gVgFTMa7ZDylxJidKGcJ4/Wj 6wdA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=W4RsQkzM; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id s205-20020a632cd6000000b0043bed49f325si15244342pgs.13.2022.10.06.01.06.50; Thu, 06 Oct 2022 01:07:19 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=W4RsQkzM; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230342AbiJFHgO (ORCPT + 99 others); Thu, 6 Oct 2022 03:36:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230345AbiJFHgE (ORCPT ); Thu, 6 Oct 2022 03:36:04 -0400 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E67AB8F948 for ; Thu, 6 Oct 2022 00:35:56 -0700 (PDT) Received: by mail-ed1-x52e.google.com with SMTP id y100so1580069ede.6 for ; Thu, 06 Oct 2022 00:35:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=0dtKZhkDgaoTTpO0pEO0vifhDrrgR+WBWj56fb3zUfQ=; b=W4RsQkzM7QFWf+K5p/TTKfFKwP/3vAkl3ikvYa4UUzVSCyQMmyAeRgkZ3zuyYZpFrb JUftfdmSzmLcggX6184vSHPvABJxE6t2J+YpnX6SsIFxwAwXEBZHJz1clQrA4TEcDNcp F/UP6XNrSQdF3jmwDZJIiY6jYzl1VG8YHYwSh7yMcsn8QpUDtktNKWLzOhO+g1b1gzji Tg6FCYROjaPOCYA/xMQR80QNQxx236f2KBJIjghQPZv2gcnCVr7SVO411apqJ6LQ9fgO NabZd8+h219Pw2vTF3RwlVmH/tLPkTLRXpj1zjUQyJLEL3s0hKi7Ed8DZP7hF1qJ73ei OWVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=0dtKZhkDgaoTTpO0pEO0vifhDrrgR+WBWj56fb3zUfQ=; b=pPtck6i0462bPW3JGQ3zoSE9C/Q6pOrMngQpe+/nZ/i+Fb86Fa3+TxUndp0U0/X+Zh lLDkLB5NmJf0K69cOiReR/DxhUyc+tkt0+Vn22cN51t0bzgILMfAgNxsvh1nr6SKQKS1 j4GjzS+b1HTJQM3fMAJNNaGsYZU+z6T3YmEkDuypxnlhAIZyyOw0zMZPpc9dFHYmWjhr 2Dn8QlNCpalTVB79Ek0+AJJDtwbhdRCpHPhU2oXCXj6BJaMOQZoSZhj7Gp1S3j7oKayq q8LqtFhW/7vUBNw0l+KLBiBY1eSvl9u5yTTqeiIGRmWE8BYrLS+YKM7+AtDR/brSKV6G UM9Q== X-Gm-Message-State: ACrzQf2Qye/nWLO53ZMILkCb0dS+DMGRlVhmyXPB+PHGeimd4OLfsjgQ 37kG4zZHHVnVASZNFR/z9KInW8Nx+ZLLMg== X-Received: by 2002:a05:6402:3550:b0:451:473a:5ca3 with SMTP id f16-20020a056402355000b00451473a5ca3mr3365421edd.48.1665041755090; Thu, 06 Oct 2022 00:35:55 -0700 (PDT) Received: from [192.168.1.93] (adsl-75.176.58.241.tellas.gr. [176.58.241.75]) by smtp.gmail.com with ESMTPSA id w3-20020a1709062f8300b0072ed9efc9dfsm9879115eji.48.2022.10.06.00.35.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 Oct 2022 00:35:54 -0700 (PDT) Message-ID: <55a22602-3ae8-b09b-61c9-1fc7c01235fc@gmail.com> Date: Thu, 6 Oct 2022 10:35:53 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH 1/2] xen/virtio: Fix n_pages calculation in xen_grant_dma_map(unmap)_page() Content-Language: en-US To: Oleksandr Tyshchenko , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Oleksandr Tyshchenko , Stefano Stabellini , Juergen Gross References: <20221005174823.1800761-1-olekstysh@gmail.com> <20221005174823.1800761-2-olekstysh@gmail.com> From: Xenia Ragiadakou In-Reply-To: <20221005174823.1800761-2-olekstysh@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,NICE_REPLY_A, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/5/22 20:48, Oleksandr Tyshchenko wrote: > From: Oleksandr Tyshchenko > > Take page offset into the account when calculating the number of pages > to be granted. > > Signed-off-by: Oleksandr Tyshchenko > Fixes: d6aca3504c7d ("xen/grant-dma-ops: Add option to restrict memory access under Xen") > --- > drivers/xen/grant-dma-ops.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c > index 8973fc1e9ccc..1998d0e8ce82 100644 > --- a/drivers/xen/grant-dma-ops.c > +++ b/drivers/xen/grant-dma-ops.c > @@ -153,7 +153,7 @@ static dma_addr_t xen_grant_dma_map_page(struct device *dev, struct page *page, > unsigned long attrs) > { > struct xen_grant_dma_data *data; > - unsigned int i, n_pages = PFN_UP(size); > + unsigned int i, n_pages = PFN_UP(offset + size); Here, why do we use PFN_UP and not XEN_PFN_UP? Also, since the variable 'n_pages' seems to refer to the number of grants (unless I got it all entirely wrong ...), wouldn't it be more suitable to call explicitly gnttab_count_grant()? If the above questions have been already answered in the past, please ignore. > grant_ref_t grant; > dma_addr_t dma_handle; > > @@ -185,7 +185,8 @@ static void xen_grant_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, > unsigned long attrs) > { > struct xen_grant_dma_data *data; > - unsigned int i, n_pages = PFN_UP(size); > + unsigned long offset = dma_handle & (PAGE_SIZE - 1); > + unsigned int i, n_pages = PFN_UP(offset + size); > grant_ref_t grant; > > if (WARN_ON(dir == DMA_NONE)) -- Xenia