Similar to the PCI version, just calling into virtio instead.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/Kconfig | 5 ++++
block/Makefile | 1 +
block/blk-mq-virtio.c | 54 +++++++++++++++++++++++++++++++++++++++++++
include/linux/blk-mq-virtio.h | 10 ++++++++
4 files changed, 70 insertions(+)
create mode 100644 block/blk-mq-virtio.c
create mode 100644 include/linux/blk-mq-virtio.h
diff --git a/block/Kconfig b/block/Kconfig
index 8bf114a3858a..3523b4f0cd8b 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -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
diff --git a/block/Makefile b/block/Makefile
index a827f988c4e6..60691949d28d 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -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
diff --git a/block/blk-mq-virtio.c b/block/blk-mq-virtio.c
new file mode 100644
index 000000000000..c3afbca11299
--- /dev/null
+++ b/block/blk-mq-virtio.c
@@ -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);
diff --git a/include/linux/blk-mq-virtio.h b/include/linux/blk-mq-virtio.h
new file mode 100644
index 000000000000..b1ef6e14744f
--- /dev/null
+++ b/include/linux/blk-mq-virtio.h
@@ -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 */
--
2.11.0
