From patchwork Fri Oct 9 15:17:19 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marc-Andr=C3=A9_Lureau?= X-Patchwork-Id: 528504 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from eggs.gnu.org (eggs.gnu.org [IPv6:2001:4830:134:3::10]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 91011140E41 for ; Sat, 10 Oct 2015 13:48:39 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=T1s2An+n; dkim-atps=neutral Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZkkD5-000880-Eb for incoming@patchwork.ozlabs.org; Fri, 09 Oct 2015 22:48:37 -0400 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on eggs.gnu.org X-Spam-Level: X-Spam-Status: No, score=0.8 required=5.0 tests=BAYES_50,T_DKIM_INVALID autolearn=disabled version=3.3.2 Received: from lists.gnu.org ([2001:4830:134:3::11]:44246) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZkbkX-0007aV-5u for incoming@patchwork.ozlabs.org; Fri, 09 Oct 2015 13:46:33 -0400 Received: from localhost ([::1]:40376 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZkbUH-0004lR-FW for incoming@patchwork.ozlabs.org; Fri, 09 Oct 2015 13:29:45 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36298) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZkZQs-0001qg-F2 for qemu-devel@nongnu.org; Fri, 09 Oct 2015 11:18:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZkZQr-0007pL-CB for qemu-devel@nongnu.org; Fri, 09 Oct 2015 11:18:06 -0400 Received: from mail-qg0-x232.google.com ([2607:f8b0:400d:c04::232]:33094) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZkZQr-0007pF-7S for qemu-devel@nongnu.org; Fri, 09 Oct 2015 11:18:05 -0400 Received: by qgew37 with SMTP id w37so12668437qge.0 for ; Fri, 09 Oct 2015 08:18:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-type:content-transfer-encoding; bh=X7U3TX+F611j5i2NxpsX+gytKjM6GDUIp0AUbNLFe2I=; b=T1s2An+nYx3s3T89Vu1taPbqOYat8OnANsRmqPlbZVeOk3lxyjn3c6nidnKgH96V6o FQVa4yVuc5U2WTcARV8aVsfSn1ICPY/Nanaz1D2tL+QT6Us75iYvxX21+2OEiLvcfvdI Oqxdp+jtaVg4r2/GySnJVy198eYqU+f4pzc4mjtwyN5HhrD/27h1jzSKHi2e7HzL+R2x 3XE0UZGIaAVTlYmGvykbQvogBYuS4C2ipVSx1e8Gh0Cl7NLYIhbtMvt5vAj5vuehAo+l kDhH3bIYMGtKroZdLKzUxrZnqxl9pK9iJfYcK1HevrHFVS4Rt7DdehA/Hvk/vnYVpEdQ Jf3Q== X-Received: by 10.140.235.210 with SMTP id g201mr16642979qhc.89.1444403884837; Fri, 09 Oct 2015 08:18:04 -0700 (PDT) Received: from localhost (bne75-h02-31-39-163-232.dsl.sta.abo.bbox.fr. [31.39.163.232]) by smtp.gmail.com with ESMTPSA id w138sm820078qkw.40.2015.10.09.08.18.03 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 09 Oct 2015 08:18:04 -0700 (PDT) From: marcandre.lureau@redhat.com To: qemu-devel@nongnu.org Date: Fri, 9 Oct 2015 17:17:19 +0200 Message-Id: <1444403861-3240-6-git-send-email-marcandre.lureau@redhat.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1444403861-3240-1-git-send-email-marcandre.lureau@redhat.com> References: <1444403861-3240-1-git-send-email-marcandre.lureau@redhat.com> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). Cc: haifeng.lin@huawei.com, mst@redhat.com, thibaut.collet@6wind.com, jasowang@redhat.com, pbonzini@redhat.com, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Subject: [Qemu-devel] [PATCH v8 05/27] util: add linux-only memfd fallback X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2001:4830:134:3::11 From: Marc-André Lureau Implement memfd_create() fallback if not available in system libc. memfd_create() is still not included in glibc today, atlhough it's been available since Linux 3.17 in Oct 2014. memfd has numerous advantages over traditional shm/mmap for ipc memory sharing with fd handler, which we are going to make use of for vhost-user logging memory in following patches. The next patches are going to introduce helpers to use best practices of memfd usage and provide some compatibility fallback. memfd.c is thus temporarily useless and eventually empty if memfd_create() is provided by the system. Signed-off-by: Marc-André Lureau --- include/qemu/memfd.h | 20 +++++++++++++++++++ util/Makefile.objs | 1 + util/memfd.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 75 insertions(+) create mode 100644 include/qemu/memfd.h create mode 100644 util/memfd.c diff --git a/include/qemu/memfd.h b/include/qemu/memfd.h new file mode 100644 index 0000000..8b1fe6a --- /dev/null +++ b/include/qemu/memfd.h @@ -0,0 +1,20 @@ +#ifndef QEMU_MEMFD_H +#define QEMU_MEMFD_H + +#include "config-host.h" + +#ifndef F_LINUX_SPECIFIC_BASE +#define F_LINUX_SPECIFIC_BASE 1024 +#endif + +#ifndef F_ADD_SEALS +#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9) +#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10) + +#define F_SEAL_SEAL 0x0001 /* prevent further seals from being set */ +#define F_SEAL_SHRINK 0x0002 /* prevent file from shrinking */ +#define F_SEAL_GROW 0x0004 /* prevent file from growing */ +#define F_SEAL_WRITE 0x0008 /* prevent writes */ +#endif + +#endif /* QEMU_MEMFD_H */ diff --git a/util/Makefile.objs b/util/Makefile.objs index f217901..bab1722 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -6,6 +6,7 @@ util-obj-$(CONFIG_POSIX) += oslib-posix.o util-obj-$(CONFIG_POSIX) += qemu-openpty.o util-obj-$(CONFIG_POSIX) += qemu-thread-posix.o util-obj-$(CONFIG_WIN32) += event_notifier-win32.o +util-obj-$(CONFIG_POSIX) += memfd.o util-obj-$(CONFIG_WIN32) += oslib-win32.o util-obj-$(CONFIG_WIN32) += qemu-thread-win32.o util-obj-y += envlist.o path.o module.o diff --git a/util/memfd.c b/util/memfd.c new file mode 100644 index 0000000..c509692 --- /dev/null +++ b/util/memfd.c @@ -0,0 +1,54 @@ +/* + * memfd.c + * + * Copyright (c) 2015 Red Hat, Inc. + * + * QEMU library functions on POSIX which are shared between QEMU and + * the QEMU tools. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "qemu/osdep.h" + +#include "qemu/memfd.h" + +#ifdef CONFIG_MEMFD +#include +#elif defined CONFIG_LINUX +#include +#include + +inline static int memfd_create(const char *name, unsigned int flags) +{ +#ifdef __NR_memfd_create + return syscall(__NR_memfd_create, name, flags); +#else + return -1; +#endif +} +#endif + +#ifndef MFD_CLOEXEC +#define MFD_CLOEXEC 0x0001U +#endif + +#ifndef MFD_ALLOW_SEALING +#define MFD_ALLOW_SEALING 0x0002U +#endif