441ea695f9
The guest side must not manipulate the index for the used buffers. Instead, remember the state of the used buffer locally and wait until it has moved. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
165 lines
4.0 KiB
C
165 lines
4.0 KiB
C
/*
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* Virtio driver bits
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*
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* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or (at
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* your option) any later version. See the COPYING file in the top-level
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* directory.
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*/
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#ifndef VIRTIO_H
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#define VIRTIO_H
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#include "s390-ccw.h"
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/* Status byte for guest to report progress, and synchronize features. */
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/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
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#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
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/* We have found a driver for the device. */
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#define VIRTIO_CONFIG_S_DRIVER 2
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/* Driver has used its parts of the config, and is happy */
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#define VIRTIO_CONFIG_S_DRIVER_OK 4
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/* We've given up on this device. */
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#define VIRTIO_CONFIG_S_FAILED 0x80
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enum virtio_dev_type {
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VIRTIO_ID_NET = 1,
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VIRTIO_ID_BLOCK = 2,
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VIRTIO_ID_CONSOLE = 3,
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VIRTIO_ID_BALLOON = 5,
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};
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struct virtio_dev_header {
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enum virtio_dev_type type : 8;
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u8 num_vq;
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u8 feature_len;
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u8 config_len;
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u8 status;
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u8 vqconfig[];
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} __attribute__((packed));
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struct virtio_vqconfig {
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u64 token;
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u64 address;
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u16 num;
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u8 pad[6];
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} __attribute__((packed));
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struct vq_info_block {
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u64 queue;
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u32 align;
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u16 index;
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u16 num;
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} __attribute__((packed));
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struct vq_config_block {
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u16 index;
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u16 num;
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} __attribute__((packed));
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struct virtio_dev {
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struct virtio_dev_header *header;
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struct virtio_vqconfig *vqconfig;
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char *host_features;
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char *guest_features;
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char *config;
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};
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#define KVM_S390_VIRTIO_RING_ALIGN 4096
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#define VRING_USED_F_NO_NOTIFY 1
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/* This marks a buffer as continuing via the next field. */
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#define VRING_DESC_F_NEXT 1
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/* This marks a buffer as write-only (otherwise read-only). */
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#define VRING_DESC_F_WRITE 2
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/* This means the buffer contains a list of buffer descriptors. */
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#define VRING_DESC_F_INDIRECT 4
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/* Internal flag to mark follow-up segments as such */
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#define VRING_HIDDEN_IS_CHAIN 256
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/* Virtio ring descriptors: 16 bytes. These can chain together via "next". */
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struct vring_desc {
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/* Address (guest-physical). */
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u64 addr;
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/* Length. */
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u32 len;
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/* The flags as indicated above. */
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u16 flags;
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/* We chain unused descriptors via this, too */
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u16 next;
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} __attribute__((packed));
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struct vring_avail {
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u16 flags;
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u16 idx;
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u16 ring[];
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} __attribute__((packed));
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/* u32 is used here for ids for padding reasons. */
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struct vring_used_elem {
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/* Index of start of used descriptor chain. */
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u32 id;
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/* Total length of the descriptor chain which was used (written to) */
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u32 len;
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} __attribute__((packed));
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struct vring_used {
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u16 flags;
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u16 idx;
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struct vring_used_elem ring[];
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} __attribute__((packed));
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struct vring {
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unsigned int num;
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int next_idx;
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int used_idx;
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struct vring_desc *desc;
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struct vring_avail *avail;
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struct vring_used *used;
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struct subchannel_id schid;
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};
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/***********************************************
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* Virtio block *
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***********************************************/
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/*
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* Command types
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*
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* Usage is a bit tricky as some bits are used as flags and some are not.
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*
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* Rules:
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* VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
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* VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own
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* and may not be combined with any of the other flags.
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*/
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/* These two define direction. */
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#define VIRTIO_BLK_T_IN 0
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#define VIRTIO_BLK_T_OUT 1
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/* This bit says it's a scsi command, not an actual read or write. */
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#define VIRTIO_BLK_T_SCSI_CMD 2
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/* Cache flush command */
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#define VIRTIO_BLK_T_FLUSH 4
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/* Barrier before this op. */
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#define VIRTIO_BLK_T_BARRIER 0x80000000
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/* This is the first element of the read scatter-gather list. */
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struct virtio_blk_outhdr {
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/* VIRTIO_BLK_T* */
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u32 type;
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/* io priority. */
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u32 ioprio;
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/* Sector (ie. 512 byte offset) */
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u64 sector;
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};
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#endif /* VIRTIO_H */
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