From patchwork Tue Jul 28 17:36:36 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: 501320 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 09A2F1402AA for ; Wed, 29 Jul 2015 03:39:30 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=GIf17VO/; dkim-atps=neutral Received: from localhost ([::1]:60197 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZK8qe-00011k-5t for incoming@patchwork.ozlabs.org; Tue, 28 Jul 2015 13:39:28 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51420) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZK8oC-0004ku-UI for qemu-devel@nongnu.org; Tue, 28 Jul 2015 13:36:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZK8oB-0000wS-RH for qemu-devel@nongnu.org; Tue, 28 Jul 2015 13:36:56 -0400 Received: from mail-qk0-x233.google.com ([2607:f8b0:400d:c09::233]:35316) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZK8oB-0000wM-MF for qemu-devel@nongnu.org; Tue, 28 Jul 2015 13:36:55 -0400 Received: by qkbm65 with SMTP id m65so53835852qkb.2 for ; Tue, 28 Jul 2015 10:36:55 -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=3/W3Qz87e2GS1VdM7NTb+a3TehcKNhjLGGutji/ySoI=; b=GIf17VO/mn9UwlO1hK8LMAfGY3AYjtTv7zI4Zbr8CtWvcfDpThkROzwtYCG8NL/39T tssNxWBERvzJxHzs+gu+w4jK9gcpdhkfCoFzJUpKH/CG0k4zS7SOdyH9b47v8FKcHNNI TKtSeMc9HaPKX5ux5nRHF8hE9aj/w464VDVqhUH2SRg3oZSfH2p7rvnB04CSz0Jb4m4Y sdHA+luLLsMA7S2wMeoot9cqIovnjlvT6xuIiDmSRe8MibfnQDAfiIv5GsMzAbTwY3bj u0YVU7bySLKfOE0ct29txnwiHKYQLHzbHoZyo+aN9TbQE6xz+x0t0xTY+VnPOlhEf9ku nxsQ== X-Received: by 10.55.15.163 with SMTP id 35mr51830287qkp.84.1438105015279; Tue, 28 Jul 2015 10:36:55 -0700 (PDT) Received: from localhost (APoitiers-257-1-21-177.w90-38.abo.wanadoo.fr. [90.38.88.177]) by smtp.gmail.com with ESMTPSA id d8sm11581747qka.21.2015.07.28.10.36.53 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Jul 2015 10:36:54 -0700 (PDT) From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= To: qemu-devel@nongnu.org Date: Tue, 28 Jul 2015 19:36:36 +0200 Message-Id: <1438105003-29501-3-git-send-email-marcandre.lureau@redhat.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1438105003-29501-1-git-send-email-marcandre.lureau@redhat.com> References: <1438105003-29501-1-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). X-Received-From: 2607:f8b0:400d:c09::233 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 v2 2/9] posix: 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 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. Signed-off-by: Marc-André Lureau --- include/qemu/memfd.h | 20 +++++++++++++++++++ util/Makefile.objs | 2 +- util/memfd.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 77 insertions(+), 1 deletion(-) 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 114d657..84c5485 100644 --- a/util/Makefile.objs +++ b/util/Makefile.objs @@ -1,6 +1,6 @@ util-obj-y = osdep.o cutils.o unicode.o qemu-timer-common.o util-obj-$(CONFIG_WIN32) += oslib-win32.o qemu-thread-win32.o event_notifier-win32.o -util-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-thread-posix.o event_notifier-posix.o qemu-openpty.o +util-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-thread-posix.o event_notifier-posix.o qemu-openpty.o memfd.o util-obj-y += envlist.o path.o module.o util-obj-$(call lnot,$(CONFIG_INT128)) += host-utils.o util-obj-y += bitmap.o bitops.o hbitmap.o diff --git a/util/memfd.c b/util/memfd.c new file mode 100644 index 0000000..a98d57e --- /dev/null +++ b/util/memfd.c @@ -0,0 +1,56 @@ +/* + * 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 "config-host.h" + +#include "qemu/memfd.h" + +#ifdef CONFIG_MEMFD +#include +#elif defined CONFIG_LINUX +#include +#include +#include + +#ifndef MFD_CLOEXEC +#define MFD_CLOEXEC 0x0001U +#endif + +#ifndef MFD_ALLOW_SEALING +#define MFD_ALLOW_SEALING 0x0002U +#endif + +static inline int memfd_create(const char *name, unsigned int flags) +{ + return syscall(__NR_memfd_create, name, flags); +} +#else /* !LINUX */ +static inline int memfd_create(const char *name, unsigned int flags) +{ + return -1; +} +#endif