From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AF3BC43219 for ; Fri, 26 Apr 2019 05:01:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F676206C1 for ; Fri, 26 Apr 2019 05:01:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728352AbfDZFBt (ORCPT ); Fri, 26 Apr 2019 01:01:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45118 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727324AbfDZFBs (ORCPT ); Fri, 26 Apr 2019 01:01:48 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 016188831D; Fri, 26 Apr 2019 05:01:48 +0000 (UTC) Received: from dhcp201-121.englab.pnq.redhat.com (unknown [10.65.16.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id 19F9B60923; Fri, 26 Apr 2019 05:01:22 +0000 (UTC) From: Pankaj Gupta To: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-acpi@vger.kernel.org, qemu-devel@nongnu.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org Cc: dan.j.williams@intel.com, zwisler@kernel.org, vishal.l.verma@intel.com, dave.jiang@intel.com, mst@redhat.com, jasowang@redhat.com, willy@infradead.org, rjw@rjwysocki.net, hch@infradead.org, lenb@kernel.org, jack@suse.cz, tytso@mit.edu, adilger.kernel@dilger.ca, darrick.wong@oracle.com, lcapitulino@redhat.com, kwolf@redhat.com, imammedo@redhat.com, jmoyer@redhat.com, nilal@redhat.com, riel@surriel.com, stefanha@redhat.com, aarcange@redhat.com, david@redhat.com, david@fromorbit.com, cohuck@redhat.com, xiaoguangrong.eric@gmail.com, pbonzini@redhat.com, kilobyte@angband.pl, yuval.shaia@oracle.com, pagupta@redhat.com Subject: [PATCH v7 2/6] virtio-pmem: Add virtio pmem driver Date: Fri, 26 Apr 2019 10:30:35 +0530 Message-Id: <20190426050039.17460-3-pagupta@redhat.com> In-Reply-To: <20190426050039.17460-1-pagupta@redhat.com> References: <20190426050039.17460-1-pagupta@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 26 Apr 2019 05:01:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/nvdimm/virtio_pmem.c | 114 +++++++++++++++++++++++++++++ drivers/virtio/Kconfig | 10 +++ drivers/virtio/Makefile | 1 + drivers/virtio/pmem.c | 118 +++++++++++++++++++++++++++++++ include/linux/virtio_pmem.h | 60 ++++++++++++++++ include/uapi/linux/virtio_ids.h | 1 + include/uapi/linux/virtio_pmem.h | 10 +++ 7 files changed, 314 insertions(+) create mode 100644 drivers/nvdimm/virtio_pmem.c create mode 100644 drivers/virtio/pmem.c create mode 100644 include/linux/virtio_pmem.h create mode 100644 include/uapi/linux/virtio_pmem.h diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c new file mode 100644 index 000000000000..66b582f751a3 --- /dev/null +++ b/drivers/nvdimm/virtio_pmem.c @@ -0,0 +1,114 @@ +// 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 +#include "nd.h" + + /* The interrupt handler */ +void host_ack(struct virtqueue *vq) +{ + unsigned int len; + unsigned long flags; + struct virtio_pmem_request *req, *req_buf; + struct virtio_pmem *vpmem = vq->vdev->priv; + + spin_lock_irqsave(&vpmem->pmem_lock, flags); + while ((req = virtqueue_get_buf(vq, &len)) != NULL) { + req->done = true; + wake_up(&req->host_acked); + + if (!list_empty(&vpmem->req_list)) { + req_buf = list_first_entry(&vpmem->req_list, + struct virtio_pmem_request, list); + list_del(&vpmem->req_list); + req_buf->wq_buf_avail = true; + wake_up(&req_buf->wq_buf); + } + } + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); +} +EXPORT_SYMBOL_GPL(host_ack); + + /* The request submission function */ +int virtio_pmem_flush(struct nd_region *nd_region) +{ + int err; + unsigned long flags; + struct scatterlist *sgs[2], sg, ret; + struct virtio_device *vdev = nd_region->provider_data; + struct virtio_pmem *vpmem = vdev->priv; + struct virtio_pmem_request *req; + + might_sleep(); + req = kmalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return -ENOMEM; + + req->done = req->wq_buf_avail = false; + strcpy(req->name, "FLUSH"); + init_waitqueue_head(&req->host_acked); + init_waitqueue_head(&req->wq_buf); + sg_init_one(&sg, req->name, strlen(req->name)); + sgs[0] = &sg; + sg_init_one(&ret, &req->ret, sizeof(req->ret)); + sgs[1] = &ret; + + spin_lock_irqsave(&vpmem->pmem_lock, flags); + err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req, GFP_ATOMIC); + if (err) { + dev_err(&vdev->dev, "failed to send command to virtio pmem device\n"); + + list_add_tail(&vpmem->req_list, &req->list); + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); + + /* When host has read buffer, this completes via host_ack */ + wait_event(req->wq_buf, req->wq_buf_avail); + spin_lock_irqsave(&vpmem->pmem_lock, flags); + } + err = virtqueue_kick(vpmem->req_vq); + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); + + if (!err) { + err = -EIO; + goto ret; + } + /* When host has read buffer, this completes via host_ack */ + wait_event(req->host_acked, req->done); + err = req->ret; +ret: + kfree(req); + return err; +}; + + /* The asynchronous flush callback function */ +int async_pmem_flush(struct nd_region *nd_region, struct bio *bio) +{ + int rc = 0; + + /* 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); + } else { + if (virtio_pmem_flush(nd_region)) + rc = -EIO; + } + + return rc; +}; +EXPORT_SYMBOL_GPL(async_pmem_flush); +MODULE_LICENSE("GPL"); diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 35897649c24f..9f634a2ed638 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -42,6 +42,16 @@ 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 support for virtio based flushing interface + for persistent memory range. + + If unsure, say M. + config VIRTIO_BALLOON tristate "Virtio balloon driver" depends on VIRTIO diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile index 3a2b5c5dcf46..143ce91eabe9 100644 --- a/drivers/virtio/Makefile +++ b/drivers/virtio/Makefile @@ -6,3 +6,4 @@ virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o +obj-$(CONFIG_VIRTIO_PMEM) += pmem.o ../nvdimm/virtio_pmem.o diff --git a/drivers/virtio/pmem.c b/drivers/virtio/pmem.c new file mode 100644 index 000000000000..309788628e41 --- /dev/null +++ b/drivers/virtio/pmem.c @@ -0,0 +1,118 @@ +// 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 +#include <../../drivers/nvdimm/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, + 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) +{ + int err = 0; + struct resource res; + struct virtio_pmem *vpmem; + struct nd_region_desc ndr_desc = {}; + int nid = dev_to_node(&vdev->dev); + struct nd_region *nd_region; + + 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) + 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) + 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) + goto out_nd; + nd_region->provider_data = dev_to_virtio + (nd_region->dev.parent->parent); + return 0; +out_nd: + err = -ENXIO; + nvdimm_bus_unregister(vpmem->nvdimm_bus); +out_vq: + vdev->config->del_vqs(vdev); +out_err: + dev_err(&vdev->dev, "failed to register virtio pmem memory\n"); + 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"); diff --git a/include/linux/virtio_pmem.h b/include/linux/virtio_pmem.h new file mode 100644 index 000000000000..ab1da877575d --- /dev/null +++ b/include/linux/virtio_pmem.h @@ -0,0 +1,60 @@ +/* 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 +#include +#include +#include +#include +#include + +struct virtio_pmem_request { + /* Host return status corresponding to flush request */ + int ret; + + /* command name*/ + char name[16]; + + /* 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 */ + uint64_t start; + uint64_t size; +}; + +void host_ack(struct virtqueue *vq); +int async_pmem_flush(struct nd_region *nd_region, struct bio *bio); +#endif diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h index 6d5c3b2d4f4d..32b2f94d1f58 100644 --- a/include/uapi/linux/virtio_ids.h +++ b/include/uapi/linux/virtio_ids.h @@ -43,5 +43,6 @@ #define VIRTIO_ID_INPUT 18 /* virtio input */ #define VIRTIO_ID_VSOCK 19 /* virtio vsock transport */ #define VIRTIO_ID_CRYPTO 20 /* virtio crypto */ +#define VIRTIO_ID_PMEM 27 /* virtio pmem */ #endif /* _LINUX_VIRTIO_IDS_H */ diff --git a/include/uapi/linux/virtio_pmem.h b/include/uapi/linux/virtio_pmem.h new file mode 100644 index 000000000000..fa3f7d52717a --- /dev/null +++ b/include/uapi/linux/virtio_pmem.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _UAPI_LINUX_VIRTIO_PMEM_H +#define _UAPI_LINUX_VIRTIO_PMEM_H + +struct virtio_pmem_config { + __le64 start; + __le64 size; +}; +#endif -- 2.20.1