37b06f8d46
This patch adds the support of DISCARD and WRITE_ZEROES commands, that have been introduced in the virtio-blk protocol to have better performance when using SSD backend. We support only one segment per request since multiple segments are not widely used and there are no userspace APIs that allow applications to submit multiple segments in a single call. Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Message-id: 20190221103314.58500-7-sgarzare@redhat.com Message-Id: <20190221103314.58500-7-sgarzare@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
89 lines
2 KiB
C
89 lines
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 request_merging;
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uint16_t num_queues;
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uint16_t queue_size;
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uint32_t max_discard_sectors;
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uint32_t max_write_zeroes_sectors;
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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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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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bool dataplane_disabled;
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bool dataplane_started;
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struct VirtIOBlockDataPlane *dataplane;
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uint64_t host_features;
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size_t config_size;
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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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VirtQueue *vq;
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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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bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq);
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#endif
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