Michael S. Tsirkin
2021-Sep-09 13:57 UTC
[PATCH 6/6] vp_vdpa: introduce legacy virtio pci driver
On Wed, Sep 08, 2021 at 08:20:37PM +0800, Wu Zongyong wrote:> This patch implements a vdpa driver for legacy virtio-pci device. And > this has been tested with the ENI(Elastic Network Interface) which is a > hardware virtio network device in Alibaba ECS baremetal instance. > > Note that legacy device doesn't support to change the virtqueue size, so > users should use get_vq_num_unchangeable callback to check if the > virqueue size can be changed.Hmm isn't this implicit in this being a legacy device?> If not, users should get the virqueue size > first by the get_vq_num_max callback first then allocate same size > memory for the virtqueue otherwise the device won't work correctly. > > Signed-off-by: Wu Zongyong <wuzongyong at linux.alibaba.com> > --- > drivers/vdpa/Kconfig | 7 + > drivers/vdpa/virtio_pci/Makefile | 1 + > drivers/vdpa/virtio_pci/vp_vdpa_common.c | 5 + > drivers/vdpa/virtio_pci/vp_vdpa_common.h | 11 + > drivers/vdpa/virtio_pci/vp_vdpa_legacy.c | 346 +++++++++++++++++++++++ > 5 files changed, 370 insertions(+) > create mode 100644 drivers/vdpa/virtio_pci/vp_vdpa_legacy.c > > diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig > index a503c1b2bfd9..ccb4fdb11f0f 100644 > --- a/drivers/vdpa/Kconfig > +++ b/drivers/vdpa/Kconfig > @@ -67,4 +67,11 @@ config VP_VDPA > help > This kernel module bridges virtio PCI device to vDPA bus. > > +config VP_VDPA_LEGACY > + bool "Support legacy virtio pci device" > + depends on VP_VDPA > + select VIRTIO_PCI_LIB_LEGACY > + help > + This option enables bridges legacy virito PCI device to vDPA bus. > + > endif # VDPA > diff --git a/drivers/vdpa/virtio_pci/Makefile b/drivers/vdpa/virtio_pci/Makefile > index a772d86952b1..77c52dfb8b56 100644 > --- a/drivers/vdpa/virtio_pci/Makefile > +++ b/drivers/vdpa/virtio_pci/Makefile > @@ -1,4 +1,5 @@ > # SPDX-License-Identifier: GPL-2.0 > > vp_vdpa-y += vp_vdpa_common.o vp_vdpa_modern.o > +vp_vdpa-$(CONFIG_VP_VDPA_LEGACY) += vp_vdpa_legacy.o > obj-$(CONFIG_VP_VDPA) += vp_vdpa.o > diff --git a/drivers/vdpa/virtio_pci/vp_vdpa_common.c b/drivers/vdpa/virtio_pci/vp_vdpa_common.c > index 3ff24c9ad6e4..fa91dc153244 100644 > --- a/drivers/vdpa/virtio_pci/vp_vdpa_common.c > +++ b/drivers/vdpa/virtio_pci/vp_vdpa_common.c > @@ -8,6 +8,7 @@ > * Based on virtio_pci_modern.c. > */ > > +#include "linux/err.h" > #include <linux/irqreturn.h> > #include <linux/interrupt.h> > #include "vp_vdpa_common.h" > @@ -172,6 +173,10 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id) > return ret; > > vp_vdpa = vp_vdpa_modern_probe(pdev); > + if (PTR_ERR(vp_vdpa) == -ENODEV) { > + dev_info(&pdev->dev, "Tring legacy driver"); > + vp_vdpa = vp_vdpa_legacy_probe(pdev); > + } > if (IS_ERR(vp_vdpa)) > return PTR_ERR(vp_vdpa); > > diff --git a/drivers/vdpa/virtio_pci/vp_vdpa_common.h b/drivers/vdpa/virtio_pci/vp_vdpa_common.h > index 57886b55a2e9..39f241d8321b 100644 > --- a/drivers/vdpa/virtio_pci/vp_vdpa_common.h > +++ b/drivers/vdpa/virtio_pci/vp_vdpa_common.h > @@ -10,6 +10,7 @@ > #include <linux/virtio_ring.h> > #include <linux/virtio_pci.h> > #include <linux/virtio_pci_modern.h> > +#include <linux/virtio_pci_legacy.h> > > #define VP_VDPA_DRIVER_NAME "vp_vdpa" > #define VP_VDPA_NAME_SIZE 256 > @@ -26,6 +27,7 @@ struct vp_vdpa { > struct vdpa_device vdpa; > struct pci_dev *pci_dev; > struct virtio_pci_modern_device mdev; > + struct virtio_pci_legacy_device ldev; > struct vp_vring *vring; > struct vdpa_callback config_cb; > char msix_name[VP_VDPA_NAME_SIZE]; > @@ -53,4 +55,13 @@ void vp_vdpa_free_irq_vectors(void *data); > > struct vp_vdpa *vp_vdpa_modern_probe(struct pci_dev *pdev); > > +#if IS_ENABLED(CONFIG_VP_VDPA_LEGACY) > +struct vp_vdpa *vp_vdpa_legacy_probe(struct pci_dev *pdev); > +#else > +static inline struct vp_vdpa *vp_vdpa_legacy_probe(struct pci_dev *pdev) > +{ > + return ERR_PTR(-ENODEV); > +} > +#endif > + > #endif > diff --git a/drivers/vdpa/virtio_pci/vp_vdpa_legacy.c b/drivers/vdpa/virtio_pci/vp_vdpa_legacy.c > new file mode 100644 > index 000000000000..75a6879a27ca > --- /dev/null > +++ b/drivers/vdpa/virtio_pci/vp_vdpa_legacy.c > @@ -0,0 +1,346 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * vDPA bridge driver for legacy virtio-pci device > + * > + * Copyright (c) 2021, Alibaba Inc. All rights reserved. > + * Author: Wu Zongyong <wuzongyong at linux.alibaba.com> > + */ > + > +#include "linux/pci.h" > +#include "linux/virtio_byteorder.h" > +#include "linux/virtio_pci_legacy.h" > +#include <uapi/linux/virtio_net.h> > +#include <uapi/linux/virtio_blk.h> > +#include <linux/virtio_ids.h> > +#include <linux/virtio_pci.h> > +#include "vp_vdpa_common.h" > + > +static struct virtio_pci_legacy_device *vdpa_to_ldev(struct vdpa_device *vdpa) > +{ > + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); > + > + return &vp_vdpa->ldev; > +} > + > +static u64 vp_vdpa_get_features(struct vdpa_device *vdpa) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + return vp_legacy_get_features(ldev); > +} > + > +static int vp_vdpa_set_features(struct vdpa_device *vdpa, u64 features) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + vp_legacy_set_features(ldev, features); > + > + return 0; > +} > + > +static u8 vp_vdpa_get_status(struct vdpa_device *vdpa) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + return vp_legacy_get_status(ldev); > +} > + > +static int vp_vdpa_set_vq_state_split(struct vdpa_device *vdpa, > + const struct vdpa_vq_state *state) > +{ > + const struct vdpa_vq_state_split *split = &state->split; > + > + if (split->avail_index == 0) > + return 0; > + > + return -EOPNOTSUPP; > +} > + > +static int vp_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 qid, > + const struct vdpa_vq_state *state) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + /* Note that this is not supported by virtio specification. > + * But if the state is by chance equal to the device initial > + * state, we can let it go. > + */ > + if (!vp_legacy_get_queue_enable(ldev, qid)) > + return vp_vdpa_set_vq_state_split(vdpa, state); > + > + return -EOPNOTSUPP; > +} > + > +static void vp_vdpa_set_vq_ready(struct vdpa_device *vdpa, > + u16 qid, bool ready) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + /* Legacy devices can only be activated by setting vq address, > + * and queue_enable is not supported by specification. So for > + * legacy devices, we use @vp_vdpa_set_vq_address to set vq > + * ready instead. > + */ > + if (!ready) > + vp_legacy_set_queue_address(ldev, qid, 0); > +} > + > +static bool vp_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 qid) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + return vp_legacy_get_queue_enable(ldev, qid); > +} > + > +/* Legacy devices don't support set vq num by specification, > + * just report an error if someone try to set it. > + */ > +static void vp_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 qid, > + u32 num) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + dev_err(&ldev->pci_dev->dev, "legacy device don't support set vq num\n"); > +} > + > +static u16 vp_vdpa_get_vq_num_max(struct vdpa_device *vdpa) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + /* assume all virtqueues have the same size */ > + return vp_legacy_get_queue_size(ldev, 0); > +} > + > +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_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + vp_legacy_set_queue_address(ldev, qid, desc_area >> VIRTIO_PCI_QUEUE_ADDR_SHIFT); > + > + return 0; > +} > + > +static u32 vp_vdpa_get_device_id(struct vdpa_device *vdpa) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + return ldev->id.device; > +} > + > +static u32 vp_vdpa_get_vendor_id(struct vdpa_device *vdpa) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + > + return ldev->id.vendor; > +} > + > +static size_t vp_vdpa_get_config_size(struct vdpa_device *vdpa) > +{ > + struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa); > + size_t size; > + > + switch (ldev->id.device) { > + case VIRTIO_ID_NET: > + size = sizeof(struct virtio_net_config); > + break; > + case VIRTIO_ID_BLOCK: > + size = sizeof(struct virtio_blk_config); > + break; > + default: > + size = 0; > + dev_err(&ldev->pci_dev->dev, "VIRTIO ID %u not support\n", ldev->id.device); > + } > + > + return 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_legacy_device *ldev = &vp_vdpa->ldev; > + void __iomem *ioaddr = ldev->ioaddr + > + VIRTIO_PCI_CONFIG_OFF(vp_vdpa->vectors) + > + offset; > + u8 *p = buf; > + int i; > + > + /* legacy devices don't have a configuration generation field, > + * so we just read it once. > + */ > + for (i = 0; i < len; i++) > + *p++ = ioread8(ioaddr + i); > +} > + > +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_legacy_device *ldev = &vp_vdpa->ldev; > + void __iomem *ioaddr = ldev->ioaddr + > + VIRTIO_PCI_CONFIG_OFF(vp_vdpa->vectors) + > + offset; > + const u8 *p = buf; > + int i; > + > + for (i = 0; i < len; i++) > + iowrite8(*p++, ioaddr + i); > +} > + > +static void vp_vdpa_set_status(struct vdpa_device *vdpa, u8 status) > +{ > + struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa); > + struct virtio_pci_legacy_device *ldev = &vp_vdpa->ldev; > + 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_legacy_set_status(ldev, status); > + > + if (!(status & VIRTIO_CONFIG_S_DRIVER_OK) && > + (s & VIRTIO_CONFIG_S_DRIVER_OK)) { > + vp_vdpa_free_irq(vp_vdpa); > + } > +} > + > +static bool vp_vdpa_get_vq_num_unchangeable(struct vdpa_device *vdpa) > +{ > + return true; > +} > + > +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_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_size = vp_vdpa_get_config_size, > + .get_config = vp_vdpa_get_config, > + .set_config = vp_vdpa_set_config, > + .set_config_cb = vp_vdpa_set_config_cb, > + .get_vq_irq = vp_vdpa_get_vq_irq, > + .get_vq_num_unchangeable = vp_vdpa_get_vq_num_unchangeable, > +}; > + > +static u16 vp_vdpa_get_num_queues(struct vp_vdpa *vp_vdpa) > +{ > + struct virtio_pci_legacy_device *ldev = &vp_vdpa->ldev; > + u32 features = vp_legacy_get_features(ldev); > + u16 num; > + > + switch (ldev->id.device) { > + case VIRTIO_ID_NET: > + num = 2; > + if (features & VIRTIO_NET_F_MQ) { > + __virtio16 max_virtqueue_pairs; > + > + vp_vdpa_get_config(&vp_vdpa->vdpa, > + offsetof(struct virtio_net_config, max_virtqueue_pairs), > + &max_virtqueue_pairs, > + sizeof(max_virtqueue_pairs)); > + num = 2 * __virtio16_to_cpu(virtio_legacy_is_little_endian(), > + max_virtqueue_pairs); > + } > + > + if (features & VIRTIO_NET_F_CTRL_VQ) > + num += 1; > + break; > + case VIRTIO_ID_BLOCK: > + num = 1; > + break; > + default: > + num = 0; > + dev_err(&ldev->pci_dev->dev, "VIRTIO ID %u not support\n", ldev->id.device); > + } > + > + return num; > +} > + > +static u16 vp_vdpa_queue_vector(struct vp_vdpa *vp_vdpa, u16 idx, u16 vector) > +{ > + return vp_legacy_queue_vector(&vp_vdpa->ldev, idx, vector); > +} > + > +static u16 vp_vdpa_config_vector(struct vp_vdpa *vp_vdpa, u16 vector) > +{ > + return vp_legacy_config_vector(&vp_vdpa->ldev, vector); > +} > + > +struct vp_vdpa *vp_vdpa_legacy_probe(struct pci_dev *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct vp_vdpa *vp_vdpa; > + struct virtio_pci_legacy_device *ldev; > + int ret, i; > + > + 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 ERR_PTR(-ENOMEM); > + } > + > + ldev = &vp_vdpa->ldev; > + ldev->pci_dev = pdev; > + > + ret = vp_legacy_probe(ldev); > + if (ret) { > + dev_err(dev, "Failed to probe legacy 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_vdpa_get_num_queues(vp_vdpa); > + > + ret = devm_add_action_or_reset(dev, vp_vdpa_free_irq_vectors, pdev); > + if (ret) { > + dev_err(dev, > + "Failed for adding devres for freeing irq vectors\n"); > + goto err; > + } > + > + vp_vdpa->vring = devm_kcalloc(dev, vp_vdpa->queues, > + sizeof(*vp_vdpa->vring), > + GFP_KERNEL); > + if (!vp_vdpa->vring) { > + ret = -ENOMEM; > + dev_err(dev, "Fail to allocate virtqueues\n"); > + goto err; > + } > + > + for (i = 0; i < vp_vdpa->queues; i++) { > + vp_vdpa->vring[i].irq = VIRTIO_MSI_NO_VECTOR; > + vp_vdpa->vring[i].notify = ldev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY; > + vp_vdpa->vring[i].notify_pa = pci_resource_start(pdev, 0) + VIRTIO_PCI_QUEUE_NOTIFY; > + } > + vp_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR; > + > + vp_vdpa->queue_vector = vp_vdpa_queue_vector; > + vp_vdpa->config_vector = vp_vdpa_config_vector; > + > + return vp_vdpa; > + > +err: > + put_device(&vp_vdpa->vdpa.dev); > + return ERR_PTR(ret); > +} > -- > 2.31.1