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In disabled mode, virtio-blk dataplane seems to be enabled, but flow actually goes through the normal virtio path. This patch simplifies a bit the handling of disabled mode. In disabled mode, virtio_blk_handle_output might be called even if s->dataplane is not NULL. This is a bit tricky, because the current check for s->dataplane will always trigger, causing a continuous stream of calls to virtio_blk_data_plane_start. Unfortunately, these calls will not do anything. To fix this, set the "started" flag even in disabled mode, and skip virtio_blk_data_plane_start if the started flag is true. The resulting changes also prepare the code for the next patch, were virtio-blk dataplane will reuse the same virtio_blk_handle_output function as "regular" virtio-blk. Because struct VirtIOBlockDataPlane is opaque in virtio-blk.c, we have to move s->dataplane->started inside struct VirtIOBlock. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
91 lines
2.2 KiB
C
91 lines
2.2 KiB
C
/*
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* Virtio Block Device
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*
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* Copyright IBM, Corp. 2007
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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*/
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#ifndef _QEMU_VIRTIO_BLK_H
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#define _QEMU_VIRTIO_BLK_H
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#include "standard-headers/linux/virtio_blk.h"
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#include "hw/virtio/virtio.h"
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#include "hw/block/block.h"
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#include "sysemu/iothread.h"
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#include "sysemu/block-backend.h"
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#define TYPE_VIRTIO_BLK "virtio-blk-device"
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#define VIRTIO_BLK(obj) \
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OBJECT_CHECK(VirtIOBlock, (obj), TYPE_VIRTIO_BLK)
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/* This is the last element of the write scatter-gather list */
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struct virtio_blk_inhdr
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{
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unsigned char status;
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};
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struct VirtIOBlkConf
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{
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BlockConf conf;
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IOThread *iothread;
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char *serial;
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uint32_t scsi;
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uint32_t config_wce;
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uint32_t request_merging;
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};
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struct VirtIOBlockDataPlane;
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struct VirtIOBlockReq;
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typedef struct VirtIOBlock {
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VirtIODevice parent_obj;
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BlockBackend *blk;
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VirtQueue *vq;
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void *rq;
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QEMUBH *bh;
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VirtIOBlkConf conf;
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unsigned short sector_mask;
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bool original_wce;
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VMChangeStateEntry *change;
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/* Function to push to vq and notify guest */
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void (*complete_request)(struct VirtIOBlockReq *req, unsigned char status);
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Notifier migration_state_notifier;
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bool dataplane_started;
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struct VirtIOBlockDataPlane *dataplane;
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} VirtIOBlock;
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typedef struct VirtIOBlockReq {
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VirtQueueElement elem;
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int64_t sector_num;
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VirtIOBlock *dev;
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struct virtio_blk_inhdr *in;
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struct virtio_blk_outhdr out;
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QEMUIOVector qiov;
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size_t in_len;
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struct VirtIOBlockReq *next;
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struct VirtIOBlockReq *mr_next;
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BlockAcctCookie acct;
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} VirtIOBlockReq;
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#define VIRTIO_BLK_MAX_MERGE_REQS 32
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typedef struct MultiReqBuffer {
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VirtIOBlockReq *reqs[VIRTIO_BLK_MAX_MERGE_REQS];
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unsigned int num_reqs;
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bool is_write;
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} MultiReqBuffer;
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void virtio_blk_init_request(VirtIOBlock *s, VirtIOBlockReq *req);
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void virtio_blk_free_request(VirtIOBlockReq *req);
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void virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb);
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void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb);
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#endif
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