From patchwork Tue Jun 6 07:22:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haozhong Zhang X-Patchwork-Id: 9768179 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 D2C916035D for ; Tue, 6 Jun 2017 07:26:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C6F6926E39 for ; Tue, 6 Jun 2017 07:26:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BBCCA28358; Tue, 6 Jun 2017 07:26:14 +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=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3E4F026E39 for ; Tue, 6 Jun 2017 07:26:14 +0000 (UTC) Received: from localhost ([::1]:36575 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dI8sX-0002rZ-CJ for patchwork-qemu-devel@patchwork.kernel.org; Tue, 06 Jun 2017 03:26:13 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38906) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dI8pM-0000nD-Ub for qemu-devel@nongnu.org; Tue, 06 Jun 2017 03:22:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dI8pL-0005NA-Se for qemu-devel@nongnu.org; Tue, 06 Jun 2017 03:22:56 -0400 Received: from mga03.intel.com ([134.134.136.65]:58638) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dI8pL-0005K6-Jx for qemu-devel@nongnu.org; Tue, 06 Jun 2017 03:22:55 -0400 Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Jun 2017 00:22:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,305,1493708400"; d="scan'208";a="111383321" Received: from hz-desktop.sh.intel.com (HELO localhost) ([10.239.159.149]) by fmsmga006.fm.intel.com with ESMTP; 06 Jun 2017 00:22:53 -0700 From: Haozhong Zhang To: qemu-devel@nongnu.org Date: Tue, 6 Jun 2017 15:22:29 +0800 Message-Id: <20170606072229.9302-5-haozhong.zhang@intel.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170606072229.9302-1-haozhong.zhang@intel.com> References: <20170606072229.9302-1-haozhong.zhang@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.65 Subject: [Qemu-devel] [PATCH v2 4/4] util/mmap-alloc: account for DAX device in qemu_fd_getpagesize X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Haozhong Zhang , "Michael S. Tsirkin" , Stefan Hajnoczi , Xiao Guangrong , Igor Mammedov , Dan Williams Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP A DAX device may require a page size different than getpagesize(). Signed-off-by: Haozhong Zhang Reviewed-by: Stefan Hajnoczi --- include/qemu/osdep.h | 10 ++++++++++ util/mmap-alloc.c | 6 ++++++ util/osdep.c | 23 +++++++++++++++++++++++ 3 files changed, 39 insertions(+) diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 7f26af371e..51aca88f0d 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -479,4 +479,14 @@ pid_t qemu_fork(Error **errp); */ bool qemu_fd_is_dev_dax(int fd); +/** + * qemu_get_dev_dax_align: + * + * Get the suggested alignment of a DAX device descried by @fd. + * + * Return a non-zero suggested alignment on success; return 0 if @fd + * does not describe a DAX device, or if it fails to get alignment + * of the DAX device. + */ +size_t qemu_get_dev_dax_align(int fd); #endif diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 3ec029a9ea..2d8af64b44 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -25,8 +25,14 @@ size_t qemu_fd_getpagesize(int fd) #ifdef CONFIG_LINUX struct statfs fs; int ret; + size_t align; if (fd != -1) { + align = qemu_get_dev_dax_align(fd); + if (align) { + return align; + } + do { ret = fstatfs(fd, &fs); } while (ret != 0 && errno == EINTR); diff --git a/util/osdep.c b/util/osdep.c index 02881f96bc..e7837d30b4 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -532,3 +532,26 @@ bool qemu_fd_is_dev_dax(int fd) return is_dax; } + +size_t qemu_get_dev_dax_align(int fd) +{ + size_t align = 0; + +#ifdef __linux__ + char buf[12]; + ssize_t len; + + if (!qemu_fd_is_dev_dax(fd)) { + return 0; + } + len = qemu_dev_dax_sysfs_read(fd, "device/align", buf, sizeof(buf)); + if (len <= 0) { + return 0; + } + if (qemu_strtosz(buf, NULL, &align) < 0) { + align = 0; + } +#endif /* __linux__ */ + + return align; +}