blk-mq: provide a default queue mapping for virtio device

Similar to the PCI version, just calling into virtio instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Christoph Hellwig 2017-02-05 18:15:24 +01:00 committed by Michael S. Tsirkin
parent bbaba47956
commit 73473427bb
4 changed files with 70 additions and 0 deletions

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@ -165,4 +165,9 @@ config BLK_MQ_PCI
depends on BLOCK && PCI
default y
config BLK_MQ_VIRTIO
bool
depends on BLOCK && VIRTIO
default y
source block/Kconfig.iosched

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@ -23,5 +23,6 @@ obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
obj-$(CONFIG_BLK_CMDLINE_PARSER) += cmdline-parser.o
obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
obj-$(CONFIG_BLK_MQ_PCI) += blk-mq-pci.o
obj-$(CONFIG_BLK_MQ_VIRTIO) += blk-mq-virtio.o
obj-$(CONFIG_BLK_DEV_ZONED) += blk-zoned.o
obj-$(CONFIG_BLK_WBT) += blk-wbt.o

54
block/blk-mq-virtio.c Normal file
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@ -0,0 +1,54 @@
/*
* Copyright (c) 2016 Christoph Hellwig.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/device.h>
#include <linux/blk-mq.h>
#include <linux/blk-mq-virtio.h>
#include <linux/virtio_config.h>
#include <linux/module.h>
#include "blk-mq.h"
/**
* blk_mq_virtio_map_queues - provide a default queue mapping for virtio device
* @set: tagset to provide the mapping for
* @vdev: virtio device associated with @set.
* @first_vec: first interrupt vectors to use for queues (usually 0)
*
* This function assumes the virtio device @vdev has at least as many available
* interrupt vetors as @set has queues. It will then queuery the vector
* corresponding to each queue for it's affinity mask and built queue mapping
* that maps a queue to the CPUs that have irq affinity for the corresponding
* vector.
*/
int blk_mq_virtio_map_queues(struct blk_mq_tag_set *set,
struct virtio_device *vdev, int first_vec)
{
const struct cpumask *mask;
unsigned int queue, cpu;
if (!vdev->config->get_vq_affinity)
goto fallback;
for (queue = 0; queue < set->nr_hw_queues; queue++) {
mask = vdev->config->get_vq_affinity(vdev, first_vec + queue);
if (!mask)
goto fallback;
for_each_cpu(cpu, mask)
set->mq_map[cpu] = queue;
}
return 0;
fallback:
return blk_mq_map_queues(set);
}
EXPORT_SYMBOL_GPL(blk_mq_virtio_map_queues);

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@ -0,0 +1,10 @@
#ifndef _LINUX_BLK_MQ_VIRTIO_H
#define _LINUX_BLK_MQ_VIRTIO_H
struct blk_mq_tag_set;
struct virtio_device;
int blk_mq_virtio_map_queues(struct blk_mq_tag_set *set,
struct virtio_device *vdev, int first_vec);
#endif /* _LINUX_BLK_MQ_VIRTIO_H */