From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38857) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebKRR-0007Kx-Qj for qemu-devel@nongnu.org; Tue, 16 Jan 2018 01:09:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebKRQ-0001Au-LI for qemu-devel@nongnu.org; Tue, 16 Jan 2018 01:09:49 -0500 From: Fam Zheng Date: Tue, 16 Jan 2018 14:08:56 +0800 Message-Id: <20180116060901.17413-5-famz@redhat.com> In-Reply-To: <20180116060901.17413-1-famz@redhat.com> References: <20180116060901.17413-1-famz@redhat.com> Subject: [Qemu-devel] [PATCH v6 4/9] block: Introduce buf register API List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Keith Busch , qemu-block@nongnu.org, Fam Zheng , Kevin Wolf , Max Reitz , Eric Blake , alex.williamson@redhat.com, Markus Armbruster , Stefan Hajnoczi , Karl Rister Allow block driver to map and unmap a buffer for later I/O, as a performance hint. Signed-off-by: Fam Zheng Message-Id: <20180110091846.10699-5-famz@redhat.com> Reviewed-by: Stefan Hajnoczi --- block/block-backend.c | 10 ++++++++++ block/io.c | 24 ++++++++++++++++++++++++ include/block/block.h | 11 ++++++++++- include/block/block_int.h | 9 +++++++++ include/sysemu/block-backend.h | 3 +++ 5 files changed, 56 insertions(+), 1 deletion(-) diff --git a/block/block-backend.c b/block/block-backend.c index baef8e7abc..f66349c2c9 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -2096,3 +2096,13 @@ static void blk_root_drained_end(BdrvChild *child) } } } + +void blk_register_buf(BlockBackend *blk, void *host, size_t size) +{ + bdrv_register_buf(blk_bs(blk), host, size); +} + +void blk_unregister_buf(BlockBackend *blk, void *host) +{ + bdrv_unregister_buf(blk_bs(blk), host); +} diff --git a/block/io.c b/block/io.c index 7ea402352e..89d0745e95 100644 --- a/block/io.c +++ b/block/io.c @@ -2825,3 +2825,27 @@ void bdrv_io_unplug(BlockDriverState *bs) bdrv_io_unplug(child->bs); } } + +void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size) +{ + BdrvChild *child; + + if (bs->drv && bs->drv->bdrv_register_buf) { + bs->drv->bdrv_register_buf(bs, host, size); + } + QLIST_FOREACH(child, &bs->children, next) { + bdrv_register_buf(child->bs, host, size); + } +} + +void bdrv_unregister_buf(BlockDriverState *bs, void *host) +{ + BdrvChild *child; + + if (bs->drv && bs->drv->bdrv_unregister_buf) { + bs->drv->bdrv_unregister_buf(bs, host); + } + QLIST_FOREACH(child, &bs->children, next) { + bdrv_unregister_buf(child->bs, host); + } +} diff --git a/include/block/block.h b/include/block/block.h index 9b12774ddf..2025d7ed19 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -631,5 +631,14 @@ void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, uint32_t granularity, Error **errp); - +/** + * + * bdrv_register_buf/bdrv_unregister_buf: + * + * Register/unregister a buffer for I/O. For example, VFIO drivers are + * interested to know the memory areas that would later be used for I/O, so + * that they can prepare IOMMU mapping etc., to get better performance. + */ +void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size); +void bdrv_unregister_buf(BlockDriverState *bs, void *host); #endif diff --git a/include/block/block_int.h b/include/block/block_int.h index 29cafa4236..99b9190627 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -446,6 +446,15 @@ struct BlockDriver { const char *name, Error **errp); + /** + * Register/unregister a buffer for I/O. For example, when the driver is + * interested to know the memory areas that will later be used in iovs, so + * that it can do IOMMU mapping with VFIO etc., in order to get better + * performance. In the case of VFIO drivers, this callback is used to do + * DMA mapping for hot buffers. + */ + void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size); + void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host); QLIST_ENTRY(BlockDriver) list; }; diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index c4e52a5fa3..92ab624fac 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -229,4 +229,7 @@ void blk_io_limits_enable(BlockBackend *blk, const char *group); void blk_io_limits_update_group(BlockBackend *blk, const char *group); void blk_set_force_allow_inactivate(BlockBackend *blk); +void blk_register_buf(BlockBackend *blk, void *host, size_t size); +void blk_unregister_buf(BlockBackend *blk, void *host); + #endif -- 2.14.3