From dcd042282d855edf70df90b7d61d33b515320b7a Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 8 May 2014 16:34:37 +0200 Subject: block: add bdrv_set_aio_context() Up until now all BlockDriverState instances have used the QEMU main loop for fd handlers, timers, and BHs. This is not scalable on SMP guests and hosts so we need to move to a model with multiple event loops on different host CPUs. bdrv_set_aio_context() assigns the AioContext event loop to use for a particular BlockDriverState. It first detaches the entire BlockDriverState graph from the current AioContext and then attaches to the new AioContext. This function will be used by virtio-blk data-plane to assign a BlockDriverState to its IOThread AioContext. Make bdrv_aio_set_context() public since data-plane should not include block_int.h. Signed-off-by: Stefan Hajnoczi --- include/block/block.h | 11 +++++++++++ include/block/block_int.h | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+) (limited to 'include') diff --git a/include/block/block.h b/include/block/block.h index faee3aa..292754f 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -574,4 +574,15 @@ int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag); int bdrv_debug_resume(BlockDriverState *bs, const char *tag); bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); +/** + * bdrv_set_aio_context: + * + * Changes the #AioContext used for fd handlers, timers, and BHs by this + * BlockDriverState and all its children. + * + * This function must be called from the old #AioContext or with a lock held so + * the old #AioContext is not executing. + */ +void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context); + #endif diff --git a/include/block/block_int.h b/include/block/block_int.h index f2e753f..93ec86f 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -247,6 +247,19 @@ struct BlockDriver { */ int (*bdrv_has_zero_init)(BlockDriverState *bs); + /* Remove fd handlers, timers, and other event loop callbacks so the event + * loop is no longer in use. Called with no in-flight requests and in + * depth-first traversal order with parents before child nodes. + */ + void (*bdrv_detach_aio_context)(BlockDriverState *bs); + + /* Add fd handlers, timers, and other event loop callbacks so I/O requests + * can be processed again. Called with no in-flight requests and in + * depth-first traversal order with child nodes before parent nodes. + */ + void (*bdrv_attach_aio_context)(BlockDriverState *bs, + AioContext *new_context); + QLIST_ENTRY(BlockDriver) list; }; @@ -297,6 +310,8 @@ struct BlockDriverState { const BlockDevOps *dev_ops; void *dev_opaque; + AioContext *aio_context; /* event loop used for fd handlers, timers, etc */ + char filename[1024]; char backing_file[1024]; /* if non zero, the image is a diff of this file image */ @@ -396,6 +411,27 @@ void bdrv_add_before_write_notifier(BlockDriverState *bs, */ AioContext *bdrv_get_aio_context(BlockDriverState *bs); +/** + * bdrv_detach_aio_context: + * + * May be called from .bdrv_detach_aio_context() to detach children from the + * current #AioContext. This is only needed by block drivers that manage their + * own children. Both ->file and ->backing_hd are automatically handled and + * block drivers should not call this function on them explicitly. + */ +void bdrv_detach_aio_context(BlockDriverState *bs); + +/** + * bdrv_attach_aio_context: + * + * May be called from .bdrv_attach_aio_context() to attach children to the new + * #AioContext. This is only needed by block drivers that manage their own + * children. Both ->file and ->backing_hd are automatically handled and block + * drivers should not call this function on them explicitly. + */ +void bdrv_attach_aio_context(BlockDriverState *bs, + AioContext *new_context); + #ifdef _WIN32 int is_windows_drive(const char *filename); #endif -- cgit v1.1 From 76ef2cf5493a215efc351f48ae7094d6c183fcac Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 8 May 2014 16:34:58 +0200 Subject: raw-posix: drop raw_get_aio_fd() since it is no longer used virtio-blk data-plane now uses the QEMU block layer for I/O. We do not need raw_get_aio_fd() anymore. It was a layering violation anyway, so let's get rid of it. Signed-off-by: Stefan Hajnoczi --- include/block/block.h | 9 --------- 1 file changed, 9 deletions(-) (limited to 'include') diff --git a/include/block/block.h b/include/block/block.h index 292754f..29ac56d 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -481,15 +481,6 @@ void bdrv_op_block_all(BlockDriverState *bs, Error *reason); void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason); bool bdrv_op_blocker_is_empty(BlockDriverState *bs); -#ifdef CONFIG_LINUX_AIO -int raw_get_aio_fd(BlockDriverState *bs); -#else -static inline int raw_get_aio_fd(BlockDriverState *bs) -{ - return -ENOTSUP; -} -#endif - enum BlockAcctType { BDRV_ACCT_READ, BDRV_ACCT_WRITE, -- cgit v1.1 From db519cba8713fb49aa5233e8debe61dccdd3a57f Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Thu, 15 May 2014 19:22:05 +0800 Subject: block: Move declaration of bdrv_get_aio_context to block.h block_int.h is for block layer and block drivers, other code shouldn't include it. But similar to bdrv_set_aio_context, bdrv_get_aio_context should also be accessible from outside of block layer. Move it. Signed-off-by: Fam Zheng Signed-off-by: Stefan Hajnoczi --- include/block/block.h | 7 +++++++ include/block/block_int.h | 7 ------- 2 files changed, 7 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/block/block.h b/include/block/block.h index 29ac56d..7d86e29 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -566,6 +566,13 @@ int bdrv_debug_resume(BlockDriverState *bs, const char *tag); bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); /** + * bdrv_get_aio_context: + * + * Returns: the currently bound #AioContext + */ +AioContext *bdrv_get_aio_context(BlockDriverState *bs); + +/** * bdrv_set_aio_context: * * Changes the #AioContext used for fd handlers, timers, and BHs by this diff --git a/include/block/block_int.h b/include/block/block_int.h index 93ec86f..8d58334 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -405,13 +405,6 @@ void bdrv_add_before_write_notifier(BlockDriverState *bs, NotifierWithReturn *notifier); /** - * bdrv_get_aio_context: - * - * Returns: the currently bound #AioContext - */ -AioContext *bdrv_get_aio_context(BlockDriverState *bs); - -/** * bdrv_detach_aio_context: * * May be called from .bdrv_detach_aio_context() to detach children from the -- cgit v1.1 From 5a05cbeeaaa2ec463d48c0026e8e6be243ea0bab Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Thu, 22 May 2014 16:22:42 +0800 Subject: virtio-blk: Factor out virtio_blk_handle_scsi_req from virtio_blk_handle_scsi The common logic to process a scsi request in a VirtQueueElement is extracted to a function to share with dataplane. This makes VirtIOBlockReq.scsi unused, so drop it. Signed-off-by: Fam Zheng Signed-off-by: Stefan Hajnoczi --- include/hw/virtio/virtio-blk.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index e4c41ff..4bc9b54 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -155,4 +155,7 @@ typedef struct VirtIOBlock { void virtio_blk_set_conf(DeviceState *dev, VirtIOBlkConf *blk); +int virtio_blk_handle_scsi_req(VirtIOBlock *blk, + VirtQueueElement *elem); + #endif -- cgit v1.1 From 13af91ebf08d463d3b025cd396d4d11caceac02d Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 14 May 2014 16:22:45 +0200 Subject: throttle: add throttle_detach/attach_aio_context() Block I/O throttling uses timers and currently always adds them to the main loop. Throttling will break if bdrv_set_aio_context() is used to move a BlockDriverState to a different AioContext. This patch adds throttle_detach/attach_aio_context() interfaces so the throttling timers and uses them to move timers to the new AioContext. Note that bdrv_set_aio_context() already drains all requests so we're sure no throttled requests are pending. The test cases need to be updated since the throttle_init() interface has changed. Signed-off-by: Stefan Hajnoczi Reviewed-by: Benoit Canet --- include/qemu/throttle.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/qemu/throttle.h b/include/qemu/throttle.h index ab29b0b..b890613 100644 --- a/include/qemu/throttle.h +++ b/include/qemu/throttle.h @@ -67,6 +67,11 @@ typedef struct ThrottleState { int64_t previous_leak; /* timestamp of the last leak done */ QEMUTimer * timers[2]; /* timers used to do the throttling */ QEMUClockType clock_type; /* the clock used */ + + /* Callbacks */ + QEMUTimerCB *read_timer_cb; + QEMUTimerCB *write_timer_cb; + void *timer_opaque; } ThrottleState; /* operations on single leaky buckets */ @@ -82,6 +87,7 @@ bool throttle_compute_timer(ThrottleState *ts, /* init/destroy cycle */ void throttle_init(ThrottleState *ts, + AioContext *aio_context, QEMUClockType clock_type, void (read_timer)(void *), void (write_timer)(void *), @@ -89,6 +95,10 @@ void throttle_init(ThrottleState *ts, void throttle_destroy(ThrottleState *ts); +void throttle_detach_aio_context(ThrottleState *ts); + +void throttle_attach_aio_context(ThrottleState *ts, AioContext *new_context); + bool throttle_have_timer(ThrottleState *ts); /* configuration */ -- cgit v1.1