From patchwork Mon Jan 18 05:08:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shannon Zhao X-Patchwork-Id: 8052391 Return-Path: X-Original-To: patchwork-linux-arm@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 51C19BEEE5 for ; Mon, 18 Jan 2016 05:12:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 68AA420222 for ; Mon, 18 Jan 2016 05:12:26 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7090620204 for ; Mon, 18 Jan 2016 05:12:25 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aL25V-0000oj-NV; Mon, 18 Jan 2016 05:10:45 +0000 Received: from szxga03-in.huawei.com ([119.145.14.66]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aL25R-00081i-QS for linux-arm-kernel@lists.infradead.org; Mon, 18 Jan 2016 05:10:43 +0000 Received: from 172.24.1.48 (EHLO szxeml428-hub.china.huawei.com) ([172.24.1.48]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id BUS20098; Mon, 18 Jan 2016 13:09:04 +0800 (CST) Received: from [127.0.0.1] (10.177.16.142) by szxeml428-hub.china.huawei.com (10.82.67.183) with Microsoft SMTP Server id 14.3.235.1; Mon, 18 Jan 2016 13:08:54 +0800 Message-ID: <569C7363.80106@huawei.com> Date: Mon, 18 Jan 2016 13:08:51 +0800 From: Shannon Zhao User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Stefano Stabellini Subject: Re: [Xen-devel] [PATCH v2 03/16] Xen: xlate: Use page_to_xen_pfn instead of page_to_pfn References: <1452840929-19612-1-git-send-email-zhaoshenglong@huawei.com> <1452840929-19612-4-git-send-email-zhaoshenglong@huawei.com> In-Reply-To: X-Originating-IP: [10.177.16.142] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020205.569C7372.0089, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: a5a2cc0b0cbd41022bdccb1c0f636528 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160117_211042_276381_33B0CB54 X-CRM114-Status: GOOD ( 16.45 ) X-Spam-Score: -4.2 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, linux-efi@vger.kernel.org, ard.biesheuvel@linaro.org, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, xen-devel@lists.xen.org, julien.grall@citrix.com, stefano.stabellini@citrix.com, david.vrabel@citrix.com, peter.huangpeng@huawei.com, linux-arm-kernel@lists.infradead.org, shannon.zhao@linaro.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 On 2016/1/16 1:08, Stefano Stabellini wrote: > On Fri, 15 Jan 2016, Shannon Zhao wrote: >> From: Shannon Zhao >> >> Use page_to_xen_pfn in case of 64KB page. >> >> Signed-off-by: Shannon Zhao >> --- >> drivers/xen/xlate_mmu.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c >> index 9692656..b9fcc2c 100644 >> --- a/drivers/xen/xlate_mmu.c >> +++ b/drivers/xen/xlate_mmu.c >> @@ -227,7 +227,7 @@ int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt, >> return rc; >> } >> for (i = 0; i < nr_grant_frames; i++) >> - pfns[i] = page_to_pfn(pages[i]); >> + pfns[i] = page_to_xen_pfn(pages[i]); > > Shannon, thanks for the patch. > > Keeping in mind that in the 64K case, kernel pages are 64K but xen pages > are still 4K, I think you also need to allocate > (nr_grant_frames/XEN_PFN_PER_PAGE) kernel pages (assuming that they are > allocated contiguously): nr_grant_frames refers to 4K pages, while > xen_xlate_map_ballooned_pages is allocating pages on a 64K granularity > (sizeof(pages[0]) == 64K). > > Be careful that alloc_xenballooned_pages deals with 64K pages (because > it deals with kernel pages), while xen_pfn_t is always 4K based (because > it deals with Xen pfns). > > Please test it with and without CONFIG_ARM64_64K_PAGES. Thanks! > Stefano, thanks for your explanation. How about below patch? @@ -218,22 +221,25 @@ int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt, kfree(pages); return -ENOMEM; } - rc = alloc_xenballooned_pages(nr_grant_frames, pages); + rc = alloc_xenballooned_pages(nr_pages, pages); if (rc) { - pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__, - nr_grant_frames, rc); + pr_warn("%s Couldn't balloon alloc %ld pages rc:%d\n", __func__, + nr_pages, rc); kfree(pages); kfree(pfns); return rc; } - for (i = 0; i < nr_grant_frames; i++) - pfns[i] = page_to_pfn(pages[i]); + for (i = 0; i < nr_grant_frames; i++) { + if ((i % XEN_PFN_PER_PAGE) == 0) + xen_pfn = page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]); + pfns[i] = xen_pfn++; + } - vaddr = vmap(pages, nr_grant_frames, 0, PAGE_KERNEL); + vaddr = vmap(pages, nr_pages, 0, PAGE_KERNEL); if (!vaddr) { - pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__, - nr_grant_frames, rc); - free_xenballooned_pages(nr_grant_frames, pages); + pr_warn("%s Couldn't map %ld pages rc:%d\n", __func__, + nr_pages, rc); + free_xenballooned_pages(nr_pages, pages); kfree(pages); kfree(pfns); return -ENOMEM; diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c index 9692656..e1f7c95 100644 --- a/drivers/xen/xlate_mmu.c +++ b/drivers/xen/xlate_mmu.c @@ -207,9 +207,12 @@ int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt, void *vaddr; int rc; unsigned int i; + unsigned long nr_pages; + xen_pfn_t xen_pfn = 0; BUG_ON(nr_grant_frames == 0); - pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL); + nr_pages = DIV_ROUND_UP(nr_grant_frames, XEN_PFN_PER_PAGE); + pages = kcalloc(nr_pages, sizeof(pages[0]), GFP_KERNEL); if (!pages) return -ENOMEM;