qemu-e2k/include/hw/virtio/virtio-blk.h
Fam Zheng 0793169870 virtio: Report real progress in VQ aio poll handler
In virtio_queue_host_notifier_aio_poll, not all "!virtio_queue_empty()"
cases are making true progress.

Currently the offending one is virtio-scsi event queue, whose handler
does nothing if no event is pending. As a result aio_poll() will spin on
the "non-empty" VQ and take 100% host CPU.

Fix this by reporting actual progress from virtio queue aio handlers.

Reported-by: Ed Swierk <eswierk@skyportsystems.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Tested-by: Ed Swierk <eswierk@skyportsystems.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-02-17 21:52:30 +02:00

86 lines
1.9 KiB
C

/*
* Virtio Block Device
*
* Copyright IBM, Corp. 2007
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#ifndef QEMU_VIRTIO_BLK_H
#define QEMU_VIRTIO_BLK_H
#include "standard-headers/linux/virtio_blk.h"
#include "hw/virtio/virtio.h"
#include "hw/block/block.h"
#include "sysemu/iothread.h"
#include "sysemu/block-backend.h"
#define TYPE_VIRTIO_BLK "virtio-blk-device"
#define VIRTIO_BLK(obj) \
OBJECT_CHECK(VirtIOBlock, (obj), TYPE_VIRTIO_BLK)
/* This is the last element of the write scatter-gather list */
struct virtio_blk_inhdr
{
unsigned char status;
};
struct VirtIOBlkConf
{
BlockConf conf;
IOThread *iothread;
char *serial;
uint32_t scsi;
uint32_t config_wce;
uint32_t request_merging;
uint16_t num_queues;
};
struct VirtIOBlockDataPlane;
struct VirtIOBlockReq;
typedef struct VirtIOBlock {
VirtIODevice parent_obj;
BlockBackend *blk;
void *rq;
QEMUBH *bh;
VirtIOBlkConf conf;
unsigned short sector_mask;
bool original_wce;
VMChangeStateEntry *change;
bool dataplane_disabled;
bool dataplane_started;
struct VirtIOBlockDataPlane *dataplane;
} VirtIOBlock;
typedef struct VirtIOBlockReq {
VirtQueueElement elem;
int64_t sector_num;
VirtIOBlock *dev;
VirtQueue *vq;
struct virtio_blk_inhdr *in;
struct virtio_blk_outhdr out;
QEMUIOVector qiov;
size_t in_len;
struct VirtIOBlockReq *next;
struct VirtIOBlockReq *mr_next;
BlockAcctCookie acct;
} VirtIOBlockReq;
#define VIRTIO_BLK_MAX_MERGE_REQS 32
typedef struct MultiReqBuffer {
VirtIOBlockReq *reqs[VIRTIO_BLK_MAX_MERGE_REQS];
unsigned int num_reqs;
bool is_write;
} MultiReqBuffer;
bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq);
#endif