From 64b9f64f80a6f4b7ea51bf0510119cb15e801dc6 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Tue, 23 Feb 2021 14:19:05 +0800 Subject: [PATCH] vdpa: introduce virtio pci driver This patch introduce a vDPA driver for virtio-pci device. It bridges the virtio-pci control command to the vDPA bus. This will be used for features prototyping and testing. Note that get/restore virtqueue state is not supported which needs extension on the virtio specification. Signed-off-by: Jason Wang Link: https://lore.kernel.org/r/20210223061905.422659-4-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin --- drivers/Makefile | 1 + drivers/vdpa/Kconfig | 7 + drivers/vdpa/Makefile | 1 + drivers/vdpa/virtio_pci/Makefile | 2 + drivers/vdpa/virtio_pci/vp_vdpa.c | 458 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 469 insertions(+) create mode 100644 drivers/vdpa/virtio_pci/Makefile create mode 100644 drivers/vdpa/virtio_pci/vp_vdpa.c diff --git a/drivers/Makefile b/drivers/Makefile index 6fba7daba591..5ba932437869 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -42,6 +42,7 @@ obj-$(CONFIG_DMADEVICES) += dma/ obj-y += soc/ obj-$(CONFIG_VIRTIO) += virtio/ +obj-$(CONFIG_VIRTIO_PCI_LIB) += virtio/ obj-$(CONFIG_VDPA) += vdpa/ obj-$(CONFIG_XEN) += xen/ diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig index ffd1e098bfd2..a245809c99d0 100644 --- a/drivers/vdpa/Kconfig +++ b/drivers/vdpa/Kconfig @@ -52,4 +52,11 @@ config MLX5_VDPA_NET be executed by the hardware. It also supports a variety of stateless offloads depending on the actual device used and firmware version. +config VP_VDPA + tristate "Virtio PCI bridge vDPA driver" + select VIRTIO_PCI_LIB + depends on PCI_MSI + help + This kernel module bridges virtio PCI device to vDPA bus. + endif # VDPA diff --git a/drivers/vdpa/Makefile b/drivers/vdpa/Makefile index d160e9b63a66..67fe7f3d6943 100644 --- a/drivers/vdpa/Makefile +++ b/drivers/vdpa/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_VDPA) += vdpa.o obj-$(CONFIG_VDPA_SIM) += vdpa_sim/ obj-$(CONFIG_IFCVF) += ifcvf/ obj-$(CONFIG_MLX5_VDPA) += mlx5/ +obj-$(CONFIG_VP_VDPA) += virtio_pci/ diff --git a/drivers/vdpa/virtio_pci/Makefile b/drivers/vdpa/virtio_pci/Makefile new file mode 100644 index 000000000000..231088d3af7d --- /dev/null +++ b/drivers/vdpa/virtio_pci/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_VP_VDPA) += vp_vdpa.o diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c new file mode 100644 index 000000000000..1321a2fcd088 --- /dev/null +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c @@ -0,0 +1,458 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vDPA bridge driver for modern virtio-pci device + * + * Copyright (c) 2020, Red Hat Inc. All rights reserved. + * Author: Jason Wang + * + * Based on virtio_pci_modern.c. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define VP_VDPA_QUEUE_MAX 256 +#define VP_VDPA_DRIVER_NAME "vp_vdpa" +#define VP_VDPA_NAME_SIZE 256 + +struct vp_vring { + void __iomem *notify; + char msix_name[VP_VDPA_NAME_SIZE]; + struct vdpa_callback cb; + int irq; +}; + +struct vp_vdpa { + struct vdpa_device vdpa; + struct virtio_pci_modern_device mdev; + struct vp_vring *vring; + struct vdpa_callback config_cb; + char msix_name[VP_VDPA_NAME_SIZE]; + int config_irq; + int queues; + int vectors; +}; + +static struct vp_vdpa *vdpa_to_vp(struct vdpa_device *vdpa) +{ + return container_of(vdpa, struct vp_vdpa, vdpa); +} + +static struct virtio_pci_modern_device *vdpa_to_mdev(struct vdpa_device *vdpa) +{ + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); + + return &vp_vdpa->mdev; +} + +static u64 vp_vdpa_get_features(struct vdpa_device *vdpa) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + return vp_modern_get_features(mdev); +} + +static int vp_vdpa_set_features(struct vdpa_device *vdpa, u64 features) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + vp_modern_set_features(mdev, features); + + return 0; +} + +static u8 vp_vdpa_get_status(struct vdpa_device *vdpa) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + return vp_modern_get_status(mdev); +} + +static void vp_vdpa_free_irq(struct vp_vdpa *vp_vdpa) +{ + struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev; + struct pci_dev *pdev = mdev->pci_dev; + int i; + + for (i = 0; i < vp_vdpa->queues; i++) { + if (vp_vdpa->vring[i].irq != VIRTIO_MSI_NO_VECTOR) { + vp_modern_queue_vector(mdev, i, VIRTIO_MSI_NO_VECTOR); + devm_free_irq(&pdev->dev, vp_vdpa->vring[i].irq, + &vp_vdpa->vring[i]); + vp_vdpa->vring[i].irq = VIRTIO_MSI_NO_VECTOR; + } + } + + if (vp_vdpa->config_irq != VIRTIO_MSI_NO_VECTOR) { + vp_modern_config_vector(mdev, VIRTIO_MSI_NO_VECTOR); + devm_free_irq(&pdev->dev, vp_vdpa->config_irq, vp_vdpa); + vp_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR; + } + + if (vp_vdpa->vectors) { + pci_free_irq_vectors(pdev); + vp_vdpa->vectors = 0; + } +} + +static irqreturn_t vp_vdpa_vq_handler(int irq, void *arg) +{ + struct vp_vring *vring = arg; + + if (vring->cb.callback) + return vring->cb.callback(vring->cb.private); + + return IRQ_HANDLED; +} + +static irqreturn_t vp_vdpa_config_handler(int irq, void *arg) +{ + struct vp_vdpa *vp_vdpa = arg; + + if (vp_vdpa->config_cb.callback) + return vp_vdpa->config_cb.callback(vp_vdpa->config_cb.private); + + return IRQ_HANDLED; +} + +static int vp_vdpa_request_irq(struct vp_vdpa *vp_vdpa) +{ + struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev; + struct pci_dev *pdev = mdev->pci_dev; + int i, ret, irq; + int queues = vp_vdpa->queues; + int vectors = queues + 1; + + ret = pci_alloc_irq_vectors(pdev, vectors, vectors, PCI_IRQ_MSIX); + if (ret != vectors) { + dev_err(&pdev->dev, + "vp_vdpa: fail to allocate irq vectors want %d but %d\n", + vectors, ret); + return ret; + } + + vp_vdpa->vectors = vectors; + + for (i = 0; i < queues; i++) { + snprintf(vp_vdpa->vring[i].msix_name, VP_VDPA_NAME_SIZE, + "vp-vdpa[%s]-%d\n", pci_name(pdev), i); + irq = pci_irq_vector(pdev, i); + ret = devm_request_irq(&pdev->dev, irq, + vp_vdpa_vq_handler, + 0, vp_vdpa->vring[i].msix_name, + &vp_vdpa->vring[i]); + if (ret) { + dev_err(&pdev->dev, + "vp_vdpa: fail to request irq for vq %d\n", i); + goto err; + } + vp_modern_queue_vector(mdev, i, i); + vp_vdpa->vring[i].irq = irq; + } + + snprintf(vp_vdpa->msix_name, VP_VDPA_NAME_SIZE, "vp-vdpa[%s]-config\n", + pci_name(pdev)); + irq = pci_irq_vector(pdev, queues); + ret = devm_request_irq(&pdev->dev, irq, vp_vdpa_config_handler, 0, + vp_vdpa->msix_name, vp_vdpa); + if (ret) { + dev_err(&pdev->dev, + "vp_vdpa: fail to request irq for vq %d\n", i); + goto err; + } + vp_modern_config_vector(mdev, queues); + vp_vdpa->config_irq = irq; + + return 0; +err: + vp_vdpa_free_irq(vp_vdpa); + return ret; +} + +static void vp_vdpa_set_status(struct vdpa_device *vdpa, u8 status) +{ + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); + struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev; + u8 s = vp_vdpa_get_status(vdpa); + + if (status & VIRTIO_CONFIG_S_DRIVER_OK && + !(s & VIRTIO_CONFIG_S_DRIVER_OK)) { + vp_vdpa_request_irq(vp_vdpa); + } + + vp_modern_set_status(mdev, status); + + if (!(status & VIRTIO_CONFIG_S_DRIVER_OK) && + (s & VIRTIO_CONFIG_S_DRIVER_OK)) + vp_vdpa_free_irq(vp_vdpa); +} + +static u16 vp_vdpa_get_vq_num_max(struct vdpa_device *vdpa) +{ + return VP_VDPA_QUEUE_MAX; +} + +static int vp_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 qid, + struct vdpa_vq_state *state) +{ + /* Note that this is not supported by virtio specification, so + * we return -EOPNOTSUPP here. This means we can't support live + * migration, vhost device start/stop. + */ + return -EOPNOTSUPP; +} + +static int vp_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid, + const struct vdpa_vq_state *state) +{ + /* Note that this is not supported by virtio specification, so + * we return -ENOPOTSUPP here. This means we can't support live + * migration, vhost device start/stop. + */ + return -EOPNOTSUPP; +} + +static void vp_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 qid, + struct vdpa_callback *cb) +{ + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); + + vp_vdpa->vring[qid].cb = *cb; +} + +static void vp_vdpa_set_vq_ready(struct vdpa_device *vdpa, + u16 qid, bool ready) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + vp_modern_set_queue_enable(mdev, qid, ready); +} + +static bool vp_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 qid) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + return vp_modern_get_queue_enable(mdev, qid); +} + +static void vp_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 qid, + u32 num) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + vp_modern_set_queue_size(mdev, qid, num); +} + +static int vp_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 qid, + u64 desc_area, u64 driver_area, + u64 device_area) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + vp_modern_queue_address(mdev, qid, desc_area, + driver_area, device_area); + + return 0; +} + +static void vp_vdpa_kick_vq(struct vdpa_device *vdpa, u16 qid) +{ + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); + + vp_iowrite16(qid, vp_vdpa->vring[qid].notify); +} + +static u32 vp_vdpa_get_generation(struct vdpa_device *vdpa) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + return vp_modern_generation(mdev); +} + +static u32 vp_vdpa_get_device_id(struct vdpa_device *vdpa) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + return mdev->id.device; +} + +static u32 vp_vdpa_get_vendor_id(struct vdpa_device *vdpa) +{ + struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa); + + return mdev->id.vendor; +} + +static u32 vp_vdpa_get_vq_align(struct vdpa_device *vdpa) +{ + return PAGE_SIZE; +} + +static void vp_vdpa_get_config(struct vdpa_device *vdpa, + unsigned int offset, + void *buf, unsigned int len) +{ + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); + struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev; + u8 old, new; + u8 *p; + int i; + + do { + old = vp_ioread8(&mdev->common->config_generation); + p = buf; + for (i = 0; i < len; i++) + *p++ = vp_ioread8(mdev->device + offset + i); + + new = vp_ioread8(&mdev->common->config_generation); + } while (old != new); +} + +static void vp_vdpa_set_config(struct vdpa_device *vdpa, + unsigned int offset, const void *buf, + unsigned int len) +{ + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); + struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev; + const u8 *p = buf; + int i; + + for (i = 0; i < len; i++) + vp_iowrite8(*p++, mdev->device + offset + i); +} + +static void vp_vdpa_set_config_cb(struct vdpa_device *vdpa, + struct vdpa_callback *cb) +{ + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); + + vp_vdpa->config_cb = *cb; +} + +static const struct vdpa_config_ops vp_vdpa_ops = { + .get_features = vp_vdpa_get_features, + .set_features = vp_vdpa_set_features, + .get_status = vp_vdpa_get_status, + .set_status = vp_vdpa_set_status, + .get_vq_num_max = vp_vdpa_get_vq_num_max, + .get_vq_state = vp_vdpa_get_vq_state, + .set_vq_state = vp_vdpa_set_vq_state, + .set_vq_cb = vp_vdpa_set_vq_cb, + .set_vq_ready = vp_vdpa_set_vq_ready, + .get_vq_ready = vp_vdpa_get_vq_ready, + .set_vq_num = vp_vdpa_set_vq_num, + .set_vq_address = vp_vdpa_set_vq_address, + .kick_vq = vp_vdpa_kick_vq, + .get_generation = vp_vdpa_get_generation, + .get_device_id = vp_vdpa_get_device_id, + .get_vendor_id = vp_vdpa_get_vendor_id, + .get_vq_align = vp_vdpa_get_vq_align, + .get_config = vp_vdpa_get_config, + .set_config = vp_vdpa_set_config, + .set_config_cb = vp_vdpa_set_config_cb, +}; + +static void vp_vdpa_free_irq_vectors(void *data) +{ + pci_free_irq_vectors(data); +} + +static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id) +{ + struct virtio_pci_modern_device *mdev; + struct device *dev = &pdev->dev; + struct vp_vdpa *vp_vdpa; + u16 notify_off; + int ret, i; + + ret = pcim_enable_device(pdev); + if (ret) + return ret; + + vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa, + dev, &vp_vdpa_ops, NULL); + if (vp_vdpa == NULL) { + dev_err(dev, "vp_vdpa: Failed to allocate vDPA structure\n"); + return -ENOMEM; + } + + mdev = &vp_vdpa->mdev; + mdev->pci_dev = pdev; + + ret = vp_modern_probe(mdev); + if (ret) { + dev_err(&pdev->dev, "Failed to probe modern PCI device\n"); + goto err; + } + + pci_set_master(pdev); + pci_set_drvdata(pdev, vp_vdpa); + + vp_vdpa->vdpa.dma_dev = &pdev->dev; + vp_vdpa->queues = vp_modern_get_num_queues(mdev); + + ret = devm_add_action_or_reset(dev, vp_vdpa_free_irq_vectors, pdev); + if (ret) { + dev_err(&pdev->dev, + "Failed for adding devres for freeing irq vectors\n"); + goto err; + } + + vp_vdpa->vring = devm_kcalloc(&pdev->dev, vp_vdpa->queues, + sizeof(*vp_vdpa->vring), + GFP_KERNEL); + if (!vp_vdpa->vring) { + ret = -ENOMEM; + dev_err(&pdev->dev, "Fail to allocate virtqueues\n"); + goto err; + } + + for (i = 0; i < vp_vdpa->queues; i++) { + notify_off = vp_modern_get_queue_notify_off(mdev, i); + vp_vdpa->vring[i].irq = VIRTIO_MSI_NO_VECTOR; + vp_vdpa->vring[i].notify = mdev->notify_base + + notify_off * mdev->notify_offset_multiplier; + } + vp_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR; + + ret = vdpa_register_device(&vp_vdpa->vdpa, vp_vdpa->queues); + if (ret) { + dev_err(&pdev->dev, "Failed to register to vdpa bus\n"); + goto err; + } + + return 0; + +err: + put_device(&vp_vdpa->vdpa.dev); + return ret; +} + +static void vp_vdpa_remove(struct pci_dev *pdev) +{ + struct vp_vdpa *vp_vdpa = pci_get_drvdata(pdev); + + vdpa_unregister_device(&vp_vdpa->vdpa); + vp_modern_remove(&vp_vdpa->mdev); +} + +static struct pci_driver vp_vdpa_driver = { + .name = "vp-vdpa", + .id_table = NULL, /* only dynamic ids */ + .probe = vp_vdpa_probe, + .remove = vp_vdpa_remove, +}; + +module_pci_driver(vp_vdpa_driver); + +MODULE_AUTHOR("Jason Wang "); +MODULE_DESCRIPTION("vp-vdpa"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("1"); -- 2.11.0