Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755817AbaJWQU6 (ORCPT ); Thu, 23 Oct 2014 12:20:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61735 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753121AbaJWQU4 (ORCPT ); Thu, 23 Oct 2014 12:20:56 -0400 Date: Thu, 23 Oct 2014 19:24:03 +0300 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Rusty Russell , Greg Kroah-Hartman , "David S. Miller" , Alexei Starovoitov , Geert Uytterhoeven , Mauro Carvalho Chehab , Bjarke Istrup Pedersen , Anup Patel , =?us-ascii?B?PT9VVEYtOD9xP1Bpb3RyPTIwS3I9QzM9QjNsPz0=?= , virtualization@lists.linux-foundation.org, linux-api@vger.kernel.org Subject: [PATCH RFC v4 01/17] virtio: memory access APIs Message-ID: <1414081380-14623-2-git-send-email-mst@redhat.com> References: <1414081380-14623-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1414081380-14623-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org virtio 1.0 makes all memory structures LE, so we need APIs to conditionally do a byteswap on BE architectures. To make it easier to check code statically, add virtio specific types for multi-byte integers in memory. Add low level wrappers that do a byteswap conditionally, these will be useful e.g. for vhost. Add high level wrappers that will (in the future) query device endian-ness and act accordingly. At the moment, stub them out and assume native endian-ness everywhere. Signed-off-by: Michael S. Tsirkin --- include/linux/virtio_byteorder.h | 59 +++++++++++++++++++++++++++++++++++++++ include/linux/virtio_config.h | 42 ++++++++++++++++++++++++++++ include/uapi/linux/virtio_ring.h | 45 ++++++++++++++--------------- include/uapi/linux/virtio_types.h | 48 +++++++++++++++++++++++++++++++ include/uapi/linux/Kbuild | 1 + 5 files changed, 173 insertions(+), 22 deletions(-) create mode 100644 include/linux/virtio_byteorder.h create mode 100644 include/uapi/linux/virtio_types.h diff --git a/include/linux/virtio_byteorder.h b/include/linux/virtio_byteorder.h new file mode 100644 index 0000000..824ed0b --- /dev/null +++ b/include/linux/virtio_byteorder.h @@ -0,0 +1,59 @@ +#ifndef _LINUX_VIRTIO_BYTEORDER_H +#define _LINUX_VIRTIO_BYTEORDER_H +#include +#include + +/* + * Memory accessors for handling virtio in modern little endian and in + * compatibility native endian format. + */ + +static inline u16 __virtio16_to_cpu(bool little_endian, __virtio16 val) +{ + if (little_endian) + return le16_to_cpu((__force __le16)val); + else + return (__force u16)val; +} + +static inline __virtio16 __cpu_to_virtio16(bool little_endian, u16 val) +{ + if (little_endian) + return (__force __virtio16)cpu_to_le16(val); + else + return (__force __virtio16)val; +} + +static inline u32 __virtio32_to_cpu(bool little_endian, __virtio32 val) +{ + if (little_endian) + return le32_to_cpu((__force __le32)val); + else + return (__force u32)val; +} + +static inline __virtio32 __cpu_to_virtio32(bool little_endian, u32 val) +{ + if (little_endian) + return (__force __virtio32)cpu_to_le32(val); + else + return (__force __virtio32)val; +} + +static inline u64 __virtio64_to_cpu(bool little_endian, __virtio64 val) +{ + if (little_endian) + return le64_to_cpu((__force __le64)val); + else + return (__force u64)val; +} + +static inline __virtio64 __cpu_to_virtio64(bool little_endian, u64 val) +{ + if (little_endian) + return (__force __virtio64)cpu_to_le64(val); + else + return (__force __virtio64)val; +} + +#endif /* _LINUX_VIRTIO_BYTEORDER */ diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 7f4ef66..93c2b617 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -4,6 +4,7 @@ #include #include #include +#include #include /** @@ -152,6 +153,47 @@ int virtqueue_set_affinity(struct virtqueue *vq, int cpu) return 0; } +/* Memory accessors */ +#define DEFINE_VIRTIO_XX_TO_CPU(bits) \ +static inline u##bits virtio##bits##_to_cpu(struct virtio_device *vdev, __virtio##bits val) \ +{ \ + return __virtio##bits##_to_cpu(false, val); \ +} \ +static inline __virtio##bits cpu_to_virtio##bits(struct virtio_device *vdev, u##bits val) \ +{ \ + return __cpu_to_virtio##bits(false, val); \ +} + +static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val) +{ + return __virtio16_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val); +} + +static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val) +{ + return __cpu_to_virtio16(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val); +} + +static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val) +{ + return __virtio32_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val); +} + +static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val) +{ + return __cpu_to_virtio32(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val); +} + +static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val) +{ + return __virtio64_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val); +} + +static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val) +{ + return __cpu_to_virtio64(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val); +} + /* Config space accessors. */ #define virtio_cread(vdev, structname, member, ptr) \ do { \ diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h index a99f9b7..61c818a 100644 --- a/include/uapi/linux/virtio_ring.h +++ b/include/uapi/linux/virtio_ring.h @@ -32,6 +32,7 @@ * * Copyright Rusty Russell IBM Corporation 2007. */ #include +#include /* This marks a buffer as continuing via the next field. */ #define VRING_DESC_F_NEXT 1 @@ -61,32 +62,32 @@ /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ struct vring_desc { /* Address (guest-physical). */ - __u64 addr; + __virtio64 addr; /* Length. */ - __u32 len; + __virtio32 len; /* The flags as indicated above. */ - __u16 flags; + __virtio16 flags; /* We chain unused descriptors via this, too */ - __u16 next; + __virtio16 next; }; struct vring_avail { - __u16 flags; - __u16 idx; - __u16 ring[]; + __virtio16 flags; + __virtio16 idx; + __virtio16 ring[]; }; /* u32 is used here for ids for padding reasons. */ struct vring_used_elem { /* Index of start of used descriptor chain. */ - __u32 id; + __virtio32 id; /* Total length of the descriptor chain which was used (written to) */ - __u32 len; + __virtio32 len; }; struct vring_used { - __u16 flags; - __u16 idx; + __virtio16 flags; + __virtio16 idx; struct vring_used_elem ring[]; }; @@ -109,25 +110,25 @@ struct vring { * struct vring_desc desc[num]; * * // A ring of available descriptor heads with free-running index. - * __u16 avail_flags; - * __u16 avail_idx; - * __u16 available[num]; - * __u16 used_event_idx; + * __virtio16 avail_flags; + * __virtio16 avail_idx; + * __virtio16 available[num]; + * __virtio16 used_event_idx; * * // Padding to the next align boundary. * char pad[]; * * // A ring of used descriptor heads with free-running index. - * __u16 used_flags; - * __u16 used_idx; + * __virtio16 used_flags; + * __virtio16 used_idx; * struct vring_used_elem used[num]; - * __u16 avail_event_idx; + * __virtio16 avail_event_idx; * }; */ /* We publish the used event index at the end of the available ring, and vice * versa. They are at the end for backwards compatibility. */ #define vring_used_event(vr) ((vr)->avail->ring[(vr)->num]) -#define vring_avail_event(vr) (*(__u16 *)&(vr)->used->ring[(vr)->num]) +#define vring_avail_event(vr) (*(__virtio16 *)&(vr)->used->ring[(vr)->num]) static inline void vring_init(struct vring *vr, unsigned int num, void *p, unsigned long align) @@ -135,15 +136,15 @@ static inline void vring_init(struct vring *vr, unsigned int num, void *p, vr->num = num; vr->desc = p; vr->avail = p + num*sizeof(struct vring_desc); - vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__u16) + vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__virtio16) + align-1) & ~(align - 1)); } static inline unsigned vring_size(unsigned int num, unsigned long align) { - return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (3 + num) + return ((sizeof(struct vring_desc) * num + sizeof(__virtio16) * (3 + num) + align - 1) & ~(align - 1)) - + sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * num; + + sizeof(__virtio16) * 3 + sizeof(struct vring_used_elem) * num; } /* The following is used with USED_EVENT_IDX and AVAIL_EVENT_IDX */ diff --git a/include/uapi/linux/virtio_types.h b/include/uapi/linux/virtio_types.h new file mode 100644 index 0000000..b90385f --- /dev/null +++ b/include/uapi/linux/virtio_types.h @@ -0,0 +1,48 @@ +#ifndef _UAPI_LINUX_VIRTIO_TYPES_H +#define _UAPI_LINUX_VIRTIO_TYPES_H +/* An interface for efficient virtio implementation, currently for use by KVM + * and lguest, but hopefully others soon. Do NOT change this since it will + * break existing servers and clients. + * + * This header is BSD licensed so anyone can use the definitions to implement + * compatible drivers/servers. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of IBM nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * Copyright (C) 2014 Red Hat, Inc. + * Author: Michael S. Tsirkin + */ +#include + +/* + * __virtio{16,32,64} have the following meaning: + * - __u{16,32,64} for virtio devices in legacy mode, accessed in native endian + * - __le{16,32,64} for standard-compliant virtio devices + */ + +typedef __u16 __bitwise__ __virtio16; +typedef __u32 __bitwise__ __virtio32; +typedef __u64 __bitwise__ __virtio64; + +#endif /* _UAPI_LINUX_VIRTIO_TYPES_H */ diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild index 6cad974..39c161a 100644 --- a/include/uapi/linux/Kbuild +++ b/include/uapi/linux/Kbuild @@ -419,6 +419,7 @@ header-y += virtio_blk.h header-y += virtio_config.h header-y += virtio_console.h header-y += virtio_ids.h +header-y += virtio_types.h header-y += virtio_net.h header-y += virtio_pci.h header-y += virtio_ring.h -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/