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dataplane: replace internal thread with IOThread

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Today virtio-blk dataplane uses a 1:1 device-per-thread model.  Now that
IOThreads have been introduced we can generalize this to N:M devices per
threads.

This patch drops thread code from dataplane in favor of running inside
an IOThread AioContext.

As a bonus we solve the case where a guest keeps submitting I/O requests
while dataplane is trying to stop.  Previously the dataplane thread
would continue to process requests until the request gave it a break.
Now we can shut down in bounded time thanks to
aio_context_acquire/release.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2014-03-03 11:30:08 +01:00
parent 6e4a876b43
commit 48ff269272
2 changed files with 60 additions and 44 deletions
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8
include/hw/virtio/virtio-blk.h
View file

@ -16,6 +16,7 @@
#include "hw/virtio/virtio.h"
#include "hw/block/block.h"
#include "sysemu/iothread.h"
#define TYPE_VIRTIO_BLK "virtio-blk-device"
#define VIRTIO_BLK(obj) \
@ -106,6 +107,7 @@ struct virtio_scsi_inhdr
struct VirtIOBlkConf
{
BlockConf conf;
IOThread *iothread;
char *serial;
uint32_t scsi;
uint32_t config_wce;
@ -140,13 +142,15 @@ typedef struct VirtIOBlock {
DEFINE_BLOCK_CHS_PROPERTIES(_state, _field.conf), \
DEFINE_PROP_STRING("serial", _state, _field.serial), \
DEFINE_PROP_BIT("config-wce", _state, _field.config_wce, 0, true), \
DEFINE_PROP_BIT("scsi", _state, _field.scsi, 0, true)
DEFINE_PROP_BIT("scsi", _state, _field.scsi, 0, true), \
DEFINE_PROP_IOTHREAD("x-iothread", _state, _field.iothread)
#else
#define DEFINE_VIRTIO_BLK_PROPERTIES(_state, _field) \
DEFINE_BLOCK_PROPERTIES(_state, _field.conf), \
DEFINE_BLOCK_CHS_PROPERTIES(_state, _field.conf), \
DEFINE_PROP_STRING("serial", _state, _field.serial), \
DEFINE_PROP_BIT("config-wce", _state, _field.config_wce, 0, true)
DEFINE_PROP_BIT("config-wce", _state, _field.config_wce, 0, true), \
DEFINE_PROP_IOTHREAD("x-iothread", _state, _field.iothread)
#endif /* __linux__ */
void virtio_blk_set_conf(DeviceState *dev, VirtIOBlkConf *blk);