Michael S. Tsirkin
2019-Apr-10 13:12 UTC
[PATCH v5 2/5] virtio-pmem: Add virtio pmem driver
On Wed, Apr 10, 2019 at 09:38:22AM +0530, Pankaj Gupta wrote:> 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 at redhat.com> > --- > drivers/nvdimm/virtio_pmem.c | 88 ++++++++++++++++++++++ > drivers/virtio/Kconfig | 10 +++ > drivers/virtio/Makefile | 1 + > drivers/virtio/pmem.c | 124 +++++++++++++++++++++++++++++++ > include/linux/virtio_pmem.h | 60 +++++++++++++++ > include/uapi/linux/virtio_ids.h | 1 + > include/uapi/linux/virtio_pmem.h | 10 +++ > 7 files changed, 294 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..01044cc2f3a3 > --- /dev/null > +++ b/drivers/nvdimm/virtio_pmem.c > @@ -0,0 +1,88 @@ > +// 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 <linux/virtio_pmem.h> > +#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; > +}; > +EXPORT_SYMBOL_GPL(virtio_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..cc9de9589d56 > --- /dev/null > +++ b/drivers/virtio/pmem.c > @@ -0,0 +1,124 @@ > +// 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 <linux/virtio_pmem.h> > +#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) > +{ > + struct virtqueue *vq; > + > + /* single vq */ > + vpmem->req_vq = vq = virtio_find_single_vq(vpmem->vdev, > + host_ack, "flush_queue"); > + if (IS_ERR(vq)) > + return PTR_ERR(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 nvdimm_bus *nvdimm_bus; > + 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 disabled\n", > + __func__); > + return -EINVAL; > + } > + > + vdev->priv = vpmem = devm_kzalloc(&vdev->dev, sizeof(*vpmem), > + GFP_KERNEL); > + if (!vpmem) { > + err = -ENOMEM; > + goto out_err; > + } > + > + vpmem->vdev = vdev; > + 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 = nvdimm_bus_register(&vdev->dev, > + &vpmem->nd_desc); > + if (!nvdimm_bus) > + goto out_vq; > + > + dev_set_drvdata(&vdev->dev, nvdimm_bus); > + > + ndr_desc.res = &res; > + ndr_desc.numa_node = nid; > + ndr_desc.flush = virtio_pmem_flush; > + set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags); > + set_bit(ND_REGION_ASYNC, &ndr_desc.flags); > + nd_region = nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc); > + nd_region->provider_data = dev_to_virtio > + (nd_region->dev.parent->parent); > + > + if (!nd_region) > + goto out_nd; > + > + return 0; > +out_nd: > + err = -ENXIO; > + nvdimm_bus_unregister(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 virtio_pmem *vpmem = vdev->priv; > + struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(&vdev->dev); > + > + nvdimm_bus_unregister(nvdimm_bus); > + vdev->config->del_vqs(vdev); > + vdev->config->reset(vdev); > + kfree(vpmem); > +} > + > +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..224f9d934be6 > --- /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 <linux/virtio_ids.h> > +#include <linux/module.h> > +#include <linux/virtio_config.h> > +#include <uapi/linux/virtio_pmem.h> > +#include <linux/libnvdimm.h> > +#include <linux/spinlock.h> > + > +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 virtio_pmem_flush(struct nd_region *nd_region); > +#endif > diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h > index 6d5c3b2d4f4d..346389565ac1 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 25 /* virtio pmem */ > > #endif /* _LINUX_VIRTIO_IDS_H */Didn't Paolo point out someone is using 25 for audio? Please, reserve an ID with the Virtio TC before using it.> 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
Pankaj Gupta
2019-Apr-10 14:03 UTC
[Qemu-devel] [PATCH v5 2/5] virtio-pmem: Add virtio pmem driver
> > On Wed, Apr 10, 2019 at 09:38:22AM +0530, Pankaj Gupta wrote: > > 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 at redhat.com> > > --- > > drivers/nvdimm/virtio_pmem.c | 88 ++++++++++++++++++++++ > > drivers/virtio/Kconfig | 10 +++ > > drivers/virtio/Makefile | 1 + > > drivers/virtio/pmem.c | 124 +++++++++++++++++++++++++++++++ > > include/linux/virtio_pmem.h | 60 +++++++++++++++ > > include/uapi/linux/virtio_ids.h | 1 + > > include/uapi/linux/virtio_pmem.h | 10 +++ > > 7 files changed, 294 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..01044cc2f3a3 > > --- /dev/null > > +++ b/drivers/nvdimm/virtio_pmem.c > > @@ -0,0 +1,88 @@ > > +// 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 <linux/virtio_pmem.h> > > +#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; > > +}; > > +EXPORT_SYMBOL_GPL(virtio_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..cc9de9589d56 > > --- /dev/null > > +++ b/drivers/virtio/pmem.c > > @@ -0,0 +1,124 @@ > > +// 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 <linux/virtio_pmem.h> > > +#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) > > +{ > > + struct virtqueue *vq; > > + > > + /* single vq */ > > + vpmem->req_vq = vq = virtio_find_single_vq(vpmem->vdev, > > + host_ack, "flush_queue"); > > + if (IS_ERR(vq)) > > + return PTR_ERR(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 nvdimm_bus *nvdimm_bus; > > + 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 disabled\n", > > + __func__); > > + return -EINVAL; > > + } > > + > > + vdev->priv = vpmem = devm_kzalloc(&vdev->dev, sizeof(*vpmem), > > + GFP_KERNEL); > > + if (!vpmem) { > > + err = -ENOMEM; > > + goto out_err; > > + } > > + > > + vpmem->vdev = vdev; > > + 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 = nvdimm_bus_register(&vdev->dev, > > + &vpmem->nd_desc); > > + if (!nvdimm_bus) > > + goto out_vq; > > + > > + dev_set_drvdata(&vdev->dev, nvdimm_bus); > > + > > + ndr_desc.res = &res; > > + ndr_desc.numa_node = nid; > > + ndr_desc.flush = virtio_pmem_flush; > > + set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags); > > + set_bit(ND_REGION_ASYNC, &ndr_desc.flags); > > + nd_region = nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc); > > + nd_region->provider_data = dev_to_virtio > > + (nd_region->dev.parent->parent); > > + > > + if (!nd_region) > > + goto out_nd; > > + > > + return 0; > > +out_nd: > > + err = -ENXIO; > > + nvdimm_bus_unregister(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 virtio_pmem *vpmem = vdev->priv; > > + struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(&vdev->dev); > > + > > + nvdimm_bus_unregister(nvdimm_bus); > > + vdev->config->del_vqs(vdev); > > + vdev->config->reset(vdev); > > + kfree(vpmem); > > +} > > + > > +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..224f9d934be6 > > --- /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 <linux/virtio_ids.h> > > +#include <linux/module.h> > > +#include <linux/virtio_config.h> > > +#include <uapi/linux/virtio_pmem.h> > > +#include <linux/libnvdimm.h> > > +#include <linux/spinlock.h> > > + > > +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 virtio_pmem_flush(struct nd_region *nd_region); > > +#endif > > diff --git a/include/uapi/linux/virtio_ids.h > > b/include/uapi/linux/virtio_ids.h > > index 6d5c3b2d4f4d..346389565ac1 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 25 /* virtio pmem */ > > > > #endif /* _LINUX_VIRTIO_IDS_H */ > > Didn't Paolo point out someone is using 25 for audio?Sorry! I did not notice this.> > Please, reserve an ID with the Virtio TC before using it.I thought I requested[1] ID 25. [1] https://github.com/oasis-tcs/virtio-spec/issues/38 [2] https://lists.oasis-open.org/archives/virtio-dev/201805/threads.html In that case I will send request for next available ID i.e 26? Thanks, Pankaj> > > 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 > >
Cornelia Huck
2019-Apr-10 14:31 UTC
[Qemu-devel] [PATCH v5 2/5] virtio-pmem: Add virtio pmem driver
On Wed, 10 Apr 2019 10:03:01 -0400 (EDT) Pankaj Gupta <pagupta at redhat.com> wrote:> > > > On Wed, Apr 10, 2019 at 09:38:22AM +0530, Pankaj Gupta wrote: > > > 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 at redhat.com>> > > diff --git a/include/uapi/linux/virtio_ids.h > > > b/include/uapi/linux/virtio_ids.h > > > index 6d5c3b2d4f4d..346389565ac1 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 25 /* virtio pmem */ > > > > > > #endif /* _LINUX_VIRTIO_IDS_H */ > > > > Didn't Paolo point out someone is using 25 for audio? > > > Sorry! I did not notice this. > > > > > Please, reserve an ID with the Virtio TC before using it. > > I thought I requested[1] ID 25. > > [1] https://github.com/oasis-tcs/virtio-spec/issues/38 > [2] https://lists.oasis-open.org/archives/virtio-dev/201805/threads.html > > In that case I will send request for next available ID i.e 26?Have the folks using this for audio sent a reservation request as well? If not, I'd say the first requester should get the id... (And yes, we need to be quicker with voting on/applying id reservations :/)