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- virtio_pmem: The new virtio_pmem facility introduces a paravirtualized

Browse source 
persistent memory device that allows a guest VM to use DAX mechanisms to
   access a host-file with host-page-cache. It arranges for MAP_SYNC to
   be disabled and instead triggers a host fsync() when a 'write-cache
   flush' command is sent to the virtual disk device.
 
 - Miscellaneous small fixups.
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Merge tag 'libnvdimm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "Primarily just the virtio_pmem driver:

   - virtio_pmem

     The new virtio_pmem facility introduces a paravirtualized
     persistent memory device that allows a guest VM to use DAX
     mechanisms to access a host-file with host-page-cache. It arranges
     for MAP_SYNC to be disabled and instead triggers a host fsync()
     when a 'write-cache flush' command is sent to the virtual disk
     device.

   - Miscellaneous small fixups"

* tag 'libnvdimm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  virtio_pmem: fix sparse warning
  xfs: disable map_sync for async flush
  ext4: disable map_sync for async flush
  dax: check synchronous mapping is supported
  dm: enable synchronous dax
  libnvdimm: add dax_dev sync flag
  virtio-pmem: Add virtio pmem driver
  libnvdimm: nd_region flush callback support
  libnvdimm, namespace: Drop uuid_t implementation detail
This commit is contained in:
Linus Torvalds 2019-07-18 10:52:08 -07:00
parent d77e9e4e18 8c2e408e73
commit f8c3500cd1
23 changed files with 508 additions and 38 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
drivers/acpi/nfit/core.c
View file

@ -2426,7 +2426,7 @@ static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw,
offset = to_interleave_offset(offset, mmio);
writeq(cmd, mmio->addr.base + offset);
nvdimm_flush(nfit_blk->nd_region);
nvdimm_flush(nfit_blk->nd_region, NULL);
if (nfit_blk->dimm_flags & NFIT_BLK_DCR_LATCH)
readq(mmio->addr.base + offset);
@ -2475,7 +2475,7 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
}
if (rw)
nvdimm_flush(nfit_blk->nd_region);
nvdimm_flush(nfit_blk->nd_region, NULL);
rc = read_blk_stat(nfit_blk, lane) ? -EIO : 0;
return rc;

2
drivers/dax/bus.c
View file

@ -388,7 +388,7 @@ struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id,
* No 'host' or dax_operations since there is no access to this
* device outside of mmap of the resulting character device.
*/
dax_dev = alloc_dax(dev_dax, NULL, NULL);
dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC);
if (!dax_dev)
goto err;

19
drivers/dax/super.c
View file

@ -195,6 +195,8 @@ enum dax_device_flags {
DAXDEV_ALIVE,
/* gate whether dax_flush() calls the low level flush routine */
DAXDEV_WRITE_CACHE,
/* flag to check if device supports synchronous flush */
DAXDEV_SYNC,
};
/**
@ -372,6 +374,18 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev)
}
EXPORT_SYMBOL_GPL(dax_write_cache_enabled);
bool __dax_synchronous(struct dax_device *dax_dev)
{
return test_bit(DAXDEV_SYNC, &dax_dev->flags);
}
EXPORT_SYMBOL_GPL(__dax_synchronous);
void __set_dax_synchronous(struct dax_device *dax_dev)
{
set_bit(DAXDEV_SYNC, &dax_dev->flags);
}
EXPORT_SYMBOL_GPL(__set_dax_synchronous);
bool dax_alive(struct dax_device *dax_dev)
{
lockdep_assert_held(&dax_srcu);
@ -526,7 +540,7 @@ static void dax_add_host(struct dax_device *dax_dev, const char *host)
}
struct dax_device *alloc_dax(void *private, const char *__host,
const struct dax_operations *ops)
const struct dax_operations *ops, unsigned long flags)
{
struct dax_device *dax_dev;
const char *host;
@ -549,6 +563,9 @@ struct dax_device *alloc_dax(void *private, const char *__host,
dax_add_host(dax_dev, host);
dax_dev->ops = ops;
dax_dev->private = private;
if (flags & DAXDEV_F_SYNC)
set_dax_synchronous(dax_dev);
return dax_dev;
err_dev:

24
drivers/md/dm-table.c
View file

@ -881,7 +881,7 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
EXPORT_SYMBOL_GPL(dm_table_set_type);
/* validate the dax capability of the target device span */
static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
int blocksize = *(int *) data;
@ -890,7 +890,15 @@ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
start, len);
}
bool dm_table_supports_dax(struct dm_table *t, int blocksize)
/* Check devices support synchronous DAX */
static int device_synchronous(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
return dax_synchronous(dev->dax_dev);
}
bool dm_table_supports_dax(struct dm_table *t,
iterate_devices_callout_fn iterate_fn, int *blocksize)
{
struct dm_target *ti;
unsigned i;
@ -903,8 +911,7 @@ bool dm_table_supports_dax(struct dm_table *t, int blocksize)
return false;
if (!ti->type->iterate_devices ||
!ti->type->iterate_devices(ti, device_supports_dax,
&blocksize))
!ti->type->iterate_devices(ti, iterate_fn, blocksize))
return false;
}
@ -940,6 +947,7 @@ static int dm_table_determine_type(struct dm_table *t)
struct dm_target *tgt;
struct list_head *devices = dm_table_get_devices(t);
enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
int page_size = PAGE_SIZE;
if (t->type != DM_TYPE_NONE) {
/* target already set the table's type */
@ -984,7 +992,7 @@ static int dm_table_determine_type(struct dm_table *t)
verify_bio_based:
/* We must use this table as bio-based */
t->type = DM_TYPE_BIO_BASED;
if (dm_table_supports_dax(t, PAGE_SIZE) ||
if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||
(list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
t->type = DM_TYPE_DAX_BIO_BASED;
} else {
@ -1883,6 +1891,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits)
{
bool wc = false, fua = false;
int page_size = PAGE_SIZE;
/*
* Copy table's limits to the DM device's request_queue
@ -1910,8 +1919,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
}
blk_queue_write_cache(q, wc, fua);
if (dm_table_supports_dax(t, PAGE_SIZE))
if (dm_table_supports_dax(t, device_supports_dax, &page_size)) {
blk_queue_flag_set(QUEUE_FLAG_DAX, q);
if (dm_table_supports_dax(t, device_synchronous, NULL))
set_dax_synchronous(t->md->dax_dev);
}
else
blk_queue_flag_clear(QUEUE_FLAG_DAX, q);

5
drivers/md/dm.c
View file

@ -1117,7 +1117,7 @@ static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bd
if (!map)
return false;
ret = dm_table_supports_dax(map, blocksize);
ret = dm_table_supports_dax(map, device_supports_dax, &blocksize);
dm_put_live_table(md, srcu_idx);
@ -1989,7 +1989,8 @@ static struct mapped_device *alloc_dev(int minor)
sprintf(md->disk->disk_name, "dm-%d", minor);
if (IS_ENABLED(CONFIG_DAX_DRIVER)) {
md->dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
md->dax_dev = alloc_dax(md, md->disk->disk_name,
&dm_dax_ops, 0);
if (!md->dax_dev)
goto bad;
}

5
drivers/md/dm.h
View file

@ -72,7 +72,10 @@ bool dm_table_bio_based(struct dm_table *t);
bool dm_table_request_based(struct dm_table *t);
void dm_table_free_md_mempools(struct dm_table *t);
struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
bool dm_table_supports_dax(struct dm_table *t, int blocksize);
bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn,
int *blocksize);
int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data);
void dm_lock_md_type(struct mapped_device *md);
void dm_unlock_md_type(struct mapped_device *md);

1
drivers/nvdimm/Makefile
View file

@ -5,6 +5,7 @@ obj-$(CONFIG_ND_BTT) += nd_btt.o
obj-$(CONFIG_ND_BLK) += nd_blk.o
obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
obj-$(CONFIG_OF_PMEM) += of_pmem.o
obj-$(CONFIG_VIRTIO_PMEM) += virtio_pmem.o nd_virtio.o
nd_pmem-y := pmem.o

6
drivers/nvdimm/claim.c
View file

@ -255,7 +255,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
sector_t sector = offset >> 9;
int rc = 0;
int rc = 0, ret = 0;
if (unlikely(!size))
return 0;
@ -293,7 +293,9 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
}
memcpy_flushcache(nsio->addr + offset, buf, size);
nvdimm_flush(to_nd_region(ndns->dev.parent));
ret = nvdimm_flush(to_nd_region(ndns->dev.parent), NULL);
if (ret)
rc = ret;
return rc;
}

8
drivers/nvdimm/namespace_devs.c
View file

@ -1822,8 +1822,8 @@ static bool has_uuid_at_pos(struct nd_region *nd_region, u8 *uuid,
&& !guid_equal(&nd_set->type_guid,
&nd_label->type_guid)) {
dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n",
nd_set->type_guid.b,
nd_label->type_guid.b);
&nd_set->type_guid,
&nd_label->type_guid);
continue;
}
@ -2227,8 +2227,8 @@ static struct device *create_namespace_blk(struct nd_region *nd_region,
if (namespace_label_has(ndd, type_guid)) {
if (!guid_equal(&nd_set->type_guid, &nd_label->type_guid)) {
dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n",
nd_set->type_guid.b,
nd_label->type_guid.b);
&nd_set->type_guid,
&nd_label->type_guid);
return ERR_PTR(-EAGAIN);
}

1
drivers/nvdimm/nd.h
View file

@ -155,6 +155,7 @@ struct nd_region {
struct badblocks bb;
struct nd_interleave_set *nd_set;
struct nd_percpu_lane __percpu *lane;
int (*flush)(struct nd_region *nd_region, struct bio *bio);
struct nd_mapping mapping[0];
};

125
drivers/nvdimm/nd_virtio.c Normal file
View file

@ -0,0 +1,125 @@
// SPDX-License-Identifier: GPL-2.0
/*
* virtio_pmem.c: Virtio pmem Driver
*
* Discovers persistent memory range information
* from host and provides a virtio based flushing
* interface.
*/
#include "virtio_pmem.h"
#include "nd.h"
/* The interrupt handler */
void virtio_pmem_host_ack(struct virtqueue *vq)
{
struct virtio_pmem *vpmem = vq->vdev->priv;
struct virtio_pmem_request *req_data, *req_buf;
unsigned long flags;
unsigned int len;
spin_lock_irqsave(&vpmem->pmem_lock, flags);
while ((req_data = virtqueue_get_buf(vq, &len)) != NULL) {
req_data->done = true;
wake_up(&req_data->host_acked);
if (!list_empty(&vpmem->req_list)) {
req_buf = list_first_entry(&vpmem->req_list,
struct virtio_pmem_request, list);
req_buf->wq_buf_avail = true;
wake_up(&req_buf->wq_buf);
list_del(&req_buf->list);
}
}
spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
}
EXPORT_SYMBOL_GPL(virtio_pmem_host_ack);
/* The request submission function */
static int virtio_pmem_flush(struct nd_region *nd_region)
{
struct virtio_device *vdev = nd_region->provider_data;
struct virtio_pmem *vpmem = vdev->priv;
struct virtio_pmem_request *req_data;
struct scatterlist *sgs[2], sg, ret;
unsigned long flags;
int err, err1;
might_sleep();
req_data = kmalloc(sizeof(*req_data), GFP_KERNEL);
if (!req_data)
return -ENOMEM;
req_data->done = false;
init_waitqueue_head(&req_data->host_acked);
init_waitqueue_head(&req_data->wq_buf);
INIT_LIST_HEAD(&req_data->list);
req_data->req.type = cpu_to_le32(VIRTIO_PMEM_REQ_TYPE_FLUSH);
sg_init_one(&sg, &req_data->req, sizeof(req_data->req));
sgs[0] = &sg;
sg_init_one(&ret, &req_data->resp.ret, sizeof(req_data->resp));
sgs[1] = &ret;
spin_lock_irqsave(&vpmem->pmem_lock, flags);
/*
* If virtqueue_add_sgs returns -ENOSPC then req_vq virtual
* queue does not have free descriptor. We add the request
* to req_list and wait for host_ack to wake us up when free
* slots are available.
*/
while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req_data,
GFP_ATOMIC)) == -ENOSPC) {
dev_info(&vdev->dev, "failed to send command to virtio pmem device, no free slots in the virtqueue\n");
req_data->wq_buf_avail = false;
list_add_tail(&req_data->list, &vpmem->req_list);
spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
/* A host response results in "host_ack" getting called */
wait_event(req_data->wq_buf, req_data->wq_buf_avail);
spin_lock_irqsave(&vpmem->pmem_lock, flags);
}
err1 = virtqueue_kick(vpmem->req_vq);
spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
/*
* virtqueue_add_sgs failed with error different than -ENOSPC, we can't
* do anything about that.
*/
if (err || !err1) {
dev_info(&vdev->dev, "failed to send command to virtio pmem device\n");
err = -EIO;
} else {
/* A host repsonse results in "host_ack" getting called */
wait_event(req_data->host_acked, req_data->done);
err = le32_to_cpu(req_data->resp.ret);
}
kfree(req_data);
return err;
};
/* The asynchronous flush callback function */
int async_pmem_flush(struct nd_region *nd_region, struct bio *bio)
{
/*
* Create child bio for asynchronous flush and chain with
* parent bio. Otherwise directly call nd_region flush.
*/
if (bio && bio->bi_iter.bi_sector != -1) {
struct bio *child = bio_alloc(GFP_ATOMIC, 0);
if (!child)
return -ENOMEM;
bio_copy_dev(child, bio);
child->bi_opf = REQ_PREFLUSH;
child->bi_iter.bi_sector = -1;
bio_chain(child, bio);
submit_bio(child);
return 0;
}
if (virtio_pmem_flush(nd_region))
return -EIO;
return 0;
};
EXPORT_SYMBOL_GPL(async_pmem_flush);
MODULE_LICENSE("GPL");

18
drivers/nvdimm/pmem.c
View file

@ -184,6 +184,7 @@ static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
{
int ret = 0;
blk_status_t rc = 0;
bool do_acct;
unsigned long start;
@ -193,7 +194,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
struct nd_region *nd_region = to_region(pmem);
if (bio->bi_opf & REQ_PREFLUSH)
nvdimm_flush(nd_region);
ret = nvdimm_flush(nd_region, bio);
do_acct = nd_iostat_start(bio, &start);
bio_for_each_segment(bvec, bio, iter) {
@ -208,7 +209,10 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
nd_iostat_end(bio, start);
if (bio->bi_opf & REQ_FUA)
nvdimm_flush(nd_region);
ret = nvdimm_flush(nd_region, bio);
if (ret)
bio->bi_status = errno_to_blk_status(ret);
bio_endio(bio);
return BLK_QC_T_NONE;
@ -362,6 +366,7 @@ static int pmem_attach_disk(struct device *dev,
struct gendisk *disk;
void *addr;
int rc;
unsigned long flags = 0UL;
pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
if (!pmem)
@ -457,14 +462,15 @@ static int pmem_attach_disk(struct device *dev,
nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
disk->bb = &pmem->bb;
dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
if (is_nvdimm_sync(nd_region))
flags = DAXDEV_F_SYNC;
dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, flags);
if (!dax_dev) {
put_disk(disk);
return -ENOMEM;
}
dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
pmem->dax_dev = dax_dev;
gendev = disk_to_dev(disk);
gendev->groups = pmem_attribute_groups;
@ -522,14 +528,14 @@ static int nd_pmem_remove(struct device *dev)
sysfs_put(pmem->bb_state);
pmem->bb_state = NULL;
}
nvdimm_flush(to_nd_region(dev->parent));
nvdimm_flush(to_nd_region(dev->parent), NULL);
return 0;
}
static void nd_pmem_shutdown(struct device *dev)
{
nvdimm_flush(to_nd_region(dev->parent));
nvdimm_flush(to_nd_region(dev->parent), NULL);
}
static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)

33
drivers/nvdimm/region_devs.c
View file

@ -287,7 +287,9 @@ static ssize_t deep_flush_store(struct device *dev, struct device_attribute *att
return rc;
if (!flush)
return -EINVAL;
nvdimm_flush(nd_region);
rc = nvdimm_flush(nd_region, NULL);
if (rc)
return rc;
return len;
}
@ -1077,6 +1079,11 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
dev->of_node = ndr_desc->of_node;
nd_region->ndr_size = resource_size(ndr_desc->res);
nd_region->ndr_start = ndr_desc->res->start;
if (ndr_desc->flush)
nd_region->flush = ndr_desc->flush;
else
nd_region->flush = NULL;
nd_device_register(dev);
return nd_region;
@ -1117,11 +1124,24 @@ struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
}
EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
{
int rc = 0;
if (!nd_region->flush)
rc = generic_nvdimm_flush(nd_region);
else {
if (nd_region->flush(nd_region, bio))
rc = -EIO;
}
return rc;
}
/**
* nvdimm_flush - flush any posted write queues between the cpu and pmem media
* @nd_region: blk or interleaved pmem region
*/
void nvdimm_flush(struct nd_region *nd_region)
int generic_nvdimm_flush(struct nd_region *nd_region)
{
struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
int i, idx;
@ -1145,6 +1165,8 @@ void nvdimm_flush(struct nd_region *nd_region)
if (ndrd_get_flush_wpq(ndrd, i, 0))
writeq(1, ndrd_get_flush_wpq(ndrd, i, idx));
wmb();
return 0;
}
EXPORT_SYMBOL_GPL(nvdimm_flush);
@ -1189,6 +1211,13 @@ int nvdimm_has_cache(struct nd_region *nd_region)
}
EXPORT_SYMBOL_GPL(nvdimm_has_cache);
bool is_nvdimm_sync(struct nd_region *nd_region)
{
return is_nd_pmem(&nd_region->dev) &&
!test_bit(ND_REGION_ASYNC, &nd_region->flags);
}
EXPORT_SYMBOL_GPL(is_nvdimm_sync);
struct conflict_context {
struct nd_region *nd_region;
resource_size_t start, size;

122
drivers/nvdimm/virtio_pmem.c Normal file
View file

@ -0,0 +1,122 @@
// SPDX-License-Identifier: GPL-2.0
/*
* virtio_pmem.c: Virtio pmem Driver
*
* Discovers persistent memory range information
* from host and registers the virtual pmem device
* with libnvdimm core.
*/
#include "virtio_pmem.h"
#include "nd.h"
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_PMEM, VIRTIO_DEV_ANY_ID },
{ 0 },
};
/* Initialize virt queue */
static int init_vq(struct virtio_pmem *vpmem)
{
/* single vq */
vpmem->req_vq = virtio_find_single_vq(vpmem->vdev,
virtio_pmem_host_ack, "flush_queue");
if (IS_ERR(vpmem->req_vq))
return PTR_ERR(vpmem->req_vq);
spin_lock_init(&vpmem->pmem_lock);
INIT_LIST_HEAD(&vpmem->req_list);
return 0;
};
static int virtio_pmem_probe(struct virtio_device *vdev)
{
struct nd_region_desc ndr_desc = {};
int nid = dev_to_node(&vdev->dev);
struct nd_region *nd_region;
struct virtio_pmem *vpmem;
struct resource res;
int err = 0;
if (!vdev->config->get) {
dev_err(&vdev->dev, "%s failure: config access disabled\n",
__func__);
return -EINVAL;
}
vpmem = devm_kzalloc(&vdev->dev, sizeof(*vpmem), GFP_KERNEL);
if (!vpmem) {
err = -ENOMEM;
goto out_err;
}
vpmem->vdev = vdev;
vdev->priv = vpmem;
err = init_vq(vpmem);
if (err) {
dev_err(&vdev->dev, "failed to initialize virtio pmem vq's\n");
goto out_err;
}
virtio_cread(vpmem->vdev, struct virtio_pmem_config,
start, &vpmem->start);
virtio_cread(vpmem->vdev, struct virtio_pmem_config,
size, &vpmem->size);
res.start = vpmem->start;
res.end = vpmem->start + vpmem->size - 1;
vpmem->nd_desc.provider_name = "virtio-pmem";
vpmem->nd_desc.module = THIS_MODULE;
vpmem->nvdimm_bus = nvdimm_bus_register(&vdev->dev,
&vpmem->nd_desc);
if (!vpmem->nvdimm_bus) {
dev_err(&vdev->dev, "failed to register device with nvdimm_bus\n");
err = -ENXIO;
goto out_vq;
}
dev_set_drvdata(&vdev->dev, vpmem->nvdimm_bus);
ndr_desc.res = &res;
ndr_desc.numa_node = nid;
ndr_desc.flush = async_pmem_flush;
set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
nd_region = nvdimm_pmem_region_create(vpmem->nvdimm_bus, &ndr_desc);
if (!nd_region) {
dev_err(&vdev->dev, "failed to create nvdimm region\n");
err = -ENXIO;
goto out_nd;
}
nd_region->provider_data = dev_to_virtio(nd_region->dev.parent->parent);
return 0;
out_nd:
nvdimm_bus_unregister(vpmem->nvdimm_bus);
out_vq:
vdev->config->del_vqs(vdev);
out_err:
return err;
}
static void virtio_pmem_remove(struct virtio_device *vdev)
{
struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(&vdev->dev);
nvdimm_bus_unregister(nvdimm_bus);
vdev->config->del_vqs(vdev);
vdev->config->reset(vdev);
}
static struct virtio_driver virtio_pmem_driver = {
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.probe = virtio_pmem_probe,
.remove = virtio_pmem_remove,
};
module_virtio_driver(virtio_pmem_driver);
MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio pmem driver");
MODULE_LICENSE("GPL");

55
drivers/nvdimm/virtio_pmem.h Normal file
View file

@ -0,0 +1,55 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* virtio_pmem.h: virtio pmem Driver
*
* Discovers persistent memory range information
* from host and provides a virtio based flushing
* interface.
**/
#ifndef _LINUX_VIRTIO_PMEM_H
#define _LINUX_VIRTIO_PMEM_H
#include <linux/module.h>
#include <uapi/linux/virtio_pmem.h>
#include <linux/libnvdimm.h>
#include <linux/spinlock.h>
struct virtio_pmem_request {
struct virtio_pmem_req req;
struct virtio_pmem_resp resp;
/* Wait queue to process deferred work after ack from host */
wait_queue_head_t host_acked;
bool done;
/* Wait queue to process deferred work after virt queue buffer avail */
wait_queue_head_t wq_buf;
bool wq_buf_avail;
struct list_head list;
};
struct virtio_pmem {
struct virtio_device *vdev;
/* Virtio pmem request queue */
struct virtqueue *req_vq;
/* nvdimm bus registers virtio pmem device */
struct nvdimm_bus *nvdimm_bus;
struct nvdimm_bus_descriptor nd_desc;
/* List to store deferred work if virtqueue is full */
struct list_head req_list;
/* Synchronize virtqueue data */
spinlock_t pmem_lock;
/* Memory region information */
__u64 start;
__u64 size;
};
void virtio_pmem_host_ack(struct virtqueue *vq);
int async_pmem_flush(struct nd_region *nd_region, struct bio *bio);
#endif

2
drivers/s390/block/dcssblk.c
View file

@ -679,7 +679,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
goto put_dev;
dev_info->dax_dev = alloc_dax(dev_info, dev_info->gd->disk_name,
&dcssblk_dax_ops);
&dcssblk_dax_ops, DAXDEV_F_SYNC);
if (!dev_info->dax_dev) {
rc = -ENOMEM;
goto put_dev;

11
drivers/virtio/Kconfig
View file

@ -43,6 +43,17 @@ config VIRTIO_PCI_LEGACY
If unsure, say Y.
config VIRTIO_PMEM
tristate "Support for virtio pmem driver"
depends on VIRTIO
depends on LIBNVDIMM
help
This driver provides access to virtio-pmem devices, storage devices
that are mapped into the physical address space - similar to NVDIMMs
- with a virtio-based flushing interface.
If unsure, say Y.
config VIRTIO_BALLOON
tristate "Virtio balloon driver"
depends on VIRTIO

10
fs/ext4/file.c
View file

@ -371,15 +371,17 @@ static const struct vm_operations_struct ext4_file_vm_ops = {
static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *inode = file->f_mapping->host;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct dax_device *dax_dev = sbi->s_daxdev;
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
if (unlikely(ext4_forced_shutdown(sbi)))
return -EIO;
/*
* We don't support synchronous mappings for non-DAX files. At least
* until someone comes with a sensible use case.
* We don't support synchronous mappings for non-DAX files and
* for DAX files if underneath dax_device is not synchronous.
*/
if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
if (!daxdev_mapping_supported(vma, dax_dev))
return -EOPNOTSUPP;
file_accessed(file);

9
fs/xfs/xfs_file.c
View file

@ -1197,11 +1197,14 @@ xfs_file_mmap(
struct file *filp,
struct vm_area_struct *vma)
{
struct dax_device *dax_dev;
dax_dev = xfs_find_daxdev_for_inode(file_inode(filp));
/*
* We don't support synchronous mappings for non-DAX files. At least
* until someone comes with a sensible use case.
* We don't support synchronous mappings for non-DAX files and
* for DAX files if underneath dax_device is not synchronous.
*/
if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
if (!daxdev_mapping_supported(vma, dax_dev))
return -EOPNOTSUPP;
file_accessed(filp);

41
include/linux/dax.h
View file

@ -7,6 +7,9 @@
#include <linux/radix-tree.h>
#include <asm/pgtable.h>
/* Flag for synchronous flush */
#define DAXDEV_F_SYNC (1UL << 0)
typedef unsigned long dax_entry_t;
struct iomap_ops;
@ -38,18 +41,40 @@ extern struct attribute_group dax_attribute_group;
#if IS_ENABLED(CONFIG_DAX)
struct dax_device *dax_get_by_host(const char *host);
struct dax_device *alloc_dax(void *private, const char *host,
const struct dax_operations *ops);
const struct dax_operations *ops, unsigned long flags);
void put_dax(struct dax_device *dax_dev);
void kill_dax(struct dax_device *dax_dev);
void dax_write_cache(struct dax_device *dax_dev, bool wc);
bool dax_write_cache_enabled(struct dax_device *dax_dev);
bool __dax_synchronous(struct dax_device *dax_dev);
static inline bool dax_synchronous(struct dax_device *dax_dev)
{
return __dax_synchronous(dax_dev);
}
void __set_dax_synchronous(struct dax_device *dax_dev);
static inline void set_dax_synchronous(struct dax_device *dax_dev)
{
__set_dax_synchronous(dax_dev);
}
/*
* Check if given mapping is supported by the file / underlying device.
*/
static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
struct dax_device *dax_dev)
{
if (!(vma->vm_flags & VM_SYNC))
return true;
if (!IS_DAX(file_inode(vma->vm_file)))
return false;
return dax_synchronous(dax_dev);
}
#else
static inline struct dax_device *dax_get_by_host(const char *host)
{
return NULL;
}
static inline struct dax_device *alloc_dax(void *private, const char *host,
const struct dax_operations *ops)
const struct dax_operations *ops, unsigned long flags)
{
/*
* Callers should check IS_ENABLED(CONFIG_DAX) to know if this
@ -70,6 +95,18 @@ static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
{
return false;
}
static inline bool dax_synchronous(struct dax_device *dax_dev)
{
return true;
}
static inline void set_dax_synchronous(struct dax_device *dax_dev)
{
}
static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
struct dax_device *dax_dev)
{
return !(vma->vm_flags & VM_SYNC);
}
#endif
struct writeback_control;

10
include/linux/libnvdimm.h
View file

@ -11,6 +11,7 @@
#include <linux/types.h>
#include <linux/uuid.h>
#include <linux/spinlock.h>
#include <linux/bio.h>
struct badrange_entry {
u64 start;
@ -57,6 +58,9 @@ enum {
*/
ND_REGION_PERSIST_MEMCTRL = 2,
/* Platform provides asynchronous flush mechanism */
ND_REGION_ASYNC = 3,
/* mark newly adjusted resources as requiring a label update */
DPA_RESOURCE_ADJUSTED = 1 << 0,
};
@ -113,6 +117,7 @@ struct nd_mapping_desc {
int position;
};
struct nd_region;
struct nd_region_desc {
struct resource *res;
struct nd_mapping_desc *mapping;
@ -125,6 +130,7 @@ struct nd_region_desc {
int target_node;
unsigned long flags;
struct device_node *of_node;
int (*flush)(struct nd_region *nd_region, struct bio *bio);
};
struct device;
@ -252,10 +258,12 @@ unsigned long nd_blk_memremap_flags(struct nd_blk_region *ndbr);
unsigned int nd_region_acquire_lane(struct nd_region *nd_region);
void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane);
u64 nd_fletcher64(void *addr, size_t len, bool le);
void nvdimm_flush(struct nd_region *nd_region);
int nvdimm_flush(struct nd_region *nd_region, struct bio *bio);
int generic_nvdimm_flush(struct nd_region *nd_region);
int nvdimm_has_flush(struct nd_region *nd_region);
int nvdimm_has_cache(struct nd_region *nd_region);
int nvdimm_in_overwrite(struct nvdimm *nvdimm);
bool is_nvdimm_sync(struct nd_region *nd_region);
static inline int nvdimm_ctl(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
unsigned int buf_len, int *cmd_rc)

1
include/uapi/linux/virtio_ids.h
View file

@ -44,5 +44,6 @@
#define VIRTIO_ID_VSOCK 19 /* virtio vsock transport */
#define VIRTIO_ID_CRYPTO 20 /* virtio crypto */
#define VIRTIO_ID_IOMMU 23 /* virtio IOMMU */
#define VIRTIO_ID_PMEM 27 /* virtio pmem */
#endif /* _LINUX_VIRTIO_IDS_H */

34
include/uapi/linux/virtio_pmem.h Normal file
View file

@ -0,0 +1,34 @@
/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
/*
* Definitions for virtio-pmem devices.
*
* Copyright (C) 2019 Red Hat, Inc.
*
* Author(s): Pankaj Gupta <pagupta@redhat.com>
*/
#ifndef _UAPI_LINUX_VIRTIO_PMEM_H
#define _UAPI_LINUX_VIRTIO_PMEM_H
#include <linux/types.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
struct virtio_pmem_config {
__u64 start;
__u64 size;
};
#define VIRTIO_PMEM_REQ_TYPE_FLUSH 0
struct virtio_pmem_resp {
/* Host return status corresponding to flush request */
__le32 ret;
};
struct virtio_pmem_req {
/* command type */
__le32 type;
};
#endif