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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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6e84200c0a
This patch adds virtio-pmem driver for KVM guest. Guest reads the persistent memory range information from Qemu over VIRTIO and registers it on nvdimm_bus. It also creates a nd_region object with the persistent memory range information so that existing 'nvdimm/pmem' driver can reserve this into system memory map. This way 'virtio-pmem' driver uses existing functionality of pmem driver to register persistent memory compatible for DAX capable filesystems. This also provides function to perform guest flush over VIRTIO from 'pmem' driver when userspace performs flush on DAX memory range. Signed-off-by: Pankaj Gupta <pagupta@redhat.com> Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jakub Staron <jstaron@google.com> Tested-by: Jakub Staron <jstaron@google.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
122 lines
3 KiB
C
122 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* virtio_pmem.c: Virtio pmem Driver
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*
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* Discovers persistent memory range information
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* from host and registers the virtual pmem device
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* with libnvdimm core.
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*/
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#include "virtio_pmem.h"
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#include "nd.h"
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static struct virtio_device_id id_table[] = {
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{ VIRTIO_ID_PMEM, VIRTIO_DEV_ANY_ID },
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{ 0 },
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};
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/* Initialize virt queue */
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static int init_vq(struct virtio_pmem *vpmem)
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{
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/* single vq */
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vpmem->req_vq = virtio_find_single_vq(vpmem->vdev,
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virtio_pmem_host_ack, "flush_queue");
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if (IS_ERR(vpmem->req_vq))
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return PTR_ERR(vpmem->req_vq);
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spin_lock_init(&vpmem->pmem_lock);
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INIT_LIST_HEAD(&vpmem->req_list);
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return 0;
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};
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static int virtio_pmem_probe(struct virtio_device *vdev)
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{
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struct nd_region_desc ndr_desc = {};
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int nid = dev_to_node(&vdev->dev);
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struct nd_region *nd_region;
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struct virtio_pmem *vpmem;
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struct resource res;
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int err = 0;
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if (!vdev->config->get) {
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dev_err(&vdev->dev, "%s failure: config access disabled\n",
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__func__);
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return -EINVAL;
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}
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vpmem = devm_kzalloc(&vdev->dev, sizeof(*vpmem), GFP_KERNEL);
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if (!vpmem) {
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err = -ENOMEM;
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goto out_err;
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}
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vpmem->vdev = vdev;
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vdev->priv = vpmem;
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err = init_vq(vpmem);
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if (err) {
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dev_err(&vdev->dev, "failed to initialize virtio pmem vq's\n");
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goto out_err;
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}
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virtio_cread(vpmem->vdev, struct virtio_pmem_config,
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start, &vpmem->start);
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virtio_cread(vpmem->vdev, struct virtio_pmem_config,
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size, &vpmem->size);
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res.start = vpmem->start;
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res.end = vpmem->start + vpmem->size - 1;
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vpmem->nd_desc.provider_name = "virtio-pmem";
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vpmem->nd_desc.module = THIS_MODULE;
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vpmem->nvdimm_bus = nvdimm_bus_register(&vdev->dev,
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&vpmem->nd_desc);
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if (!vpmem->nvdimm_bus) {
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dev_err(&vdev->dev, "failed to register device with nvdimm_bus\n");
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err = -ENXIO;
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goto out_vq;
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}
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dev_set_drvdata(&vdev->dev, vpmem->nvdimm_bus);
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ndr_desc.res = &res;
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ndr_desc.numa_node = nid;
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ndr_desc.flush = async_pmem_flush;
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set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
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set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
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nd_region = nvdimm_pmem_region_create(vpmem->nvdimm_bus, &ndr_desc);
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if (!nd_region) {
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dev_err(&vdev->dev, "failed to create nvdimm region\n");
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err = -ENXIO;
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goto out_nd;
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}
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nd_region->provider_data = dev_to_virtio(nd_region->dev.parent->parent);
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return 0;
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out_nd:
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nvdimm_bus_unregister(vpmem->nvdimm_bus);
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out_vq:
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vdev->config->del_vqs(vdev);
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out_err:
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return err;
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}
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static void virtio_pmem_remove(struct virtio_device *vdev)
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{
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struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(&vdev->dev);
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nvdimm_bus_unregister(nvdimm_bus);
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vdev->config->del_vqs(vdev);
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vdev->config->reset(vdev);
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}
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static struct virtio_driver virtio_pmem_driver = {
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.driver.name = KBUILD_MODNAME,
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.driver.owner = THIS_MODULE,
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.id_table = id_table,
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.probe = virtio_pmem_probe,
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.remove = virtio_pmem_remove,
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};
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module_virtio_driver(virtio_pmem_driver);
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MODULE_DEVICE_TABLE(virtio, id_table);
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MODULE_DESCRIPTION("Virtio pmem driver");
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MODULE_LICENSE("GPL");
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