Commit cf680fe4 authored by Changpeng Liu's avatar Changpeng Liu Committed by Darek Stojaczyk
Browse files

vhost_blk: set the maximum supported data segment based on bdev 



AIO backend requires aligned data buffers, and the maximum
IOVs supported in bdev module is defined to 32, there are
cases for Windows Guest which will send data segments more
than 32, SPDK can't process such cases, so here we can set
the 'seg_max' parameter based on bdev module capability.
Also set the maximum segment size for those requests.

Fix issue #625.

Change-Id: I0ff61e55872af17115c0b6b28425e70cb8769790
Signed-off-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/452378


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 69db40f6

lib/vhost/vhost_blk.c

+9 −3
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 


#include "spdk/env.h"

#include "spdk/bdev.h"

#include "spdk/bdev_module.h"

#include "spdk/conf.h"

#include "spdk/thread.h"

#include "spdk/likely.h"
@@ -896,6 +897,14 @@ spdk_vhost_blk_get_config(struct spdk_vhost_dev *vdev, uint8_t *config, 
	} else {

		blk_size = spdk_bdev_get_block_size(bdev);

		blkcnt = spdk_bdev_get_num_blocks(bdev);

		if (spdk_bdev_get_buf_align(bdev) > 1) {

			blkcfg.size_max = SPDK_BDEV_LARGE_BUF_MAX_SIZE;

			blkcfg.seg_max = spdk_min(SPDK_VHOST_IOVS_MAX - 2 - 1, BDEV_IO_NUM_CHILD_IOV - 2 - 1);

		} else {

			blkcfg.size_max = 131072;

			/*  -2 for REQ and RESP and -1 for region boundary splitting */

			blkcfg.seg_max = SPDK_VHOST_IOVS_MAX - 2 - 1;

		}

	}



	memset(&blkcfg, 0, sizeof(blkcfg));
@@ -904,9 +913,6 @@ spdk_vhost_blk_get_config(struct spdk_vhost_dev *vdev, uint8_t *config, 
	blkcfg.min_io_size = 1;

	/* expressed in 512 Bytes sectors */

	blkcfg.capacity = (blkcnt * blk_size) / 512;

	blkcfg.size_max = 131072;

	/*  -2 for REQ and RESP and -1 for region boundary splitting */

	blkcfg.seg_max = SPDK_VHOST_IOVS_MAX - 2 - 1;

	/* QEMU can overwrite this value when started */

	blkcfg.num_queues = SPDK_VHOST_MAX_VQUEUES;