From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44739) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTZbI-0004cu-9w for qemu-devel@nongnu.org; Thu, 05 Mar 2015 12:30:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YTZbH-0004Q2-8m for qemu-devel@nongnu.org; Thu, 05 Mar 2015 12:30:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:32841) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTZbH-0004Ps-2J for qemu-devel@nongnu.org; Thu, 05 Mar 2015 12:30:19 -0500 From: Andrea Arcangeli Date: Thu, 5 Mar 2015 18:17:46 +0100 Message-Id: <1425575884-2574-4-git-send-email-aarcange@redhat.com> In-Reply-To: <1425575884-2574-1-git-send-email-aarcange@redhat.com> References: <1425575884-2574-1-git-send-email-aarcange@redhat.com> Subject: [Qemu-devel] [PATCH 03/21] userfaultfd: uAPI List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, Android Kernel Team Cc: Robert Love , Dave Hansen , Jan Kara , Neil Brown , Stefan Hajnoczi , Andrew Jones , Sanidhya Kashyap , KOSAKI Motohiro , Michel Lespinasse , Taras Glek , zhang.zhanghailiang@huawei.com, Pavel Emelyanov , Hugh Dickins , Mel Gorman , Sasha Levin , "Dr. David Alan Gilbert" , "Huangpeng (Peter)" , Andres Lagar-Cavilla , Christopher Covington , Anthony Liguori , Paolo Bonzini , "Kirill A. Shutemov" , Keith Packard , Wenchao Xia , Juan Quintela , Andy Lutomirski , Minchan Kim , Dmitry Adamushko , Johannes Weiner , Mike Hommey , Andrew Morton , Linus Torvalds , Peter Feiner Defines the uAPI of the userfaultfd, notably the ioctl numbers and protocol. Signed-off-by: Andrea Arcangeli --- Documentation/ioctl/ioctl-number.txt | 1 + include/uapi/linux/userfaultfd.h | 81 ++++++++++++++++++++++++++++++++++++ 2 files changed, 82 insertions(+) create mode 100644 include/uapi/linux/userfaultfd.h diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index 8136e1f..be2d4a2 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -301,6 +301,7 @@ Code Seq#(hex) Include File Comments 0xA3 80-8F Port ACL in development: 0xA3 90-9F linux/dtlk.h +0xAA 00-3F linux/uapi/linux/userfaultfd.h 0xAB 00-1F linux/nbd.h 0xAC 00-1F linux/raw.h 0xAD 00 Netfilter device in development: diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h new file mode 100644 index 0000000..9a8cd56 --- /dev/null +++ b/include/uapi/linux/userfaultfd.h @@ -0,0 +1,81 @@ +/* + * include/linux/userfaultfd.h + * + * Copyright (C) 2007 Davide Libenzi + * Copyright (C) 2015 Red Hat, Inc. + * + */ + +#ifndef _LINUX_USERFAULTFD_H +#define _LINUX_USERFAULTFD_H + +#define UFFD_API ((__u64)0xAA) +/* FIXME: add "|UFFD_BIT_WP" to UFFD_API_BITS after implementing it */ +#define UFFD_API_BITS (UFFD_BIT_WRITE) +#define UFFD_API_IOCTLS \ + ((__u64)1 << _UFFDIO_REGISTER | \ + (__u64)1 << _UFFDIO_UNREGISTER | \ + (__u64)1 << _UFFDIO_API) +#define UFFD_API_RANGE_IOCTLS \ + ((__u64)1 << _UFFDIO_WAKE) + +/* + * Valid ioctl command number range with this API is from 0x00 to + * 0x3F. UFFDIO_API is the fixed number, everything else can be + * changed by implementing a different UFFD_API. If sticking to the + * same UFFD_API more ioctl can be added and userland will be aware of + * which ioctl the running kernel implements through the ioctl command + * bitmask written by the UFFDIO_API. + */ +#define _UFFDIO_REGISTER (0x00) +#define _UFFDIO_UNREGISTER (0x01) +#define _UFFDIO_WAKE (0x02) +#define _UFFDIO_API (0x3F) + +/* userfaultfd ioctl ids */ +#define UFFDIO 0xAA +#define UFFDIO_API _IOWR(UFFDIO, _UFFDIO_API, \ + struct uffdio_api) +#define UFFDIO_REGISTER _IOWR(UFFDIO, _UFFDIO_REGISTER, \ + struct uffdio_register) +#define UFFDIO_UNREGISTER _IOR(UFFDIO, _UFFDIO_UNREGISTER, \ + struct uffdio_range) +#define UFFDIO_WAKE _IOR(UFFDIO, _UFFDIO_WAKE, \ + struct uffdio_range) + +/* + * Valid bits below PAGE_SHIFT in the userfault address read through + * the read() syscall. + */ +#define UFFD_BIT_WRITE (1<<0) /* this was a write fault, MISSING or WP */ +#define UFFD_BIT_WP (1<<1) /* handle_userfault() reason VM_UFFD_WP */ +#define UFFD_BITS 2 /* two above bits used for UFFD_BIT_* mask */ + +struct uffdio_api { + /* userland asks for an API number */ + __u64 api; + + /* kernel answers below with the available features for the API */ + __u64 bits; + __u64 ioctls; +}; + +struct uffdio_range { + __u64 start; + __u64 len; +}; + +struct uffdio_register { + struct uffdio_range range; +#define UFFDIO_REGISTER_MODE_MISSING ((__u64)1<<0) +#define UFFDIO_REGISTER_MODE_WP ((__u64)1<<1) + __u64 mode; + + /* + * kernel answers which ioctl commands are available for the + * range, keep at the end as the last 8 bytes aren't read. + */ + __u64 ioctls; +}; + +#endif /* _LINUX_USERFAULTFD_H */