Re: [RFC 2/2] vhost: IFC VF vdpa layer
From: Jason Wang
Date: Wed Oct 16 2019 - 06:20:18 EST
On 2019/10/16 äå9:30, Zhu Lingshan wrote:
This commit introduced IFC VF operations for vdpa, which complys to
vhost_mdev interfaces, handles IFC VF initialization,
configuration and removal.
Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
---
drivers/vhost/ifcvf/ifcvf_main.c | 541 +++++++++++++++++++++++++++++++++++++++
1 file changed, 541 insertions(+)
create mode 100644 drivers/vhost/ifcvf/ifcvf_main.c
diff --git a/drivers/vhost/ifcvf/ifcvf_main.c b/drivers/vhost/ifcvf/ifcvf_main.c
new file mode 100644
index 000000000000..c48a29969a85
--- /dev/null
+++ b/drivers/vhost/ifcvf/ifcvf_main.c
@@ -0,0 +1,541 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 Intel Corporation.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mdev.h>
+#include <linux/pci.h>
+#include <linux/sysfs.h>
+
+#include "ifcvf_base.h"
+
+#define VERSION_STRING "0.1"
+#define DRIVER_AUTHOR "Intel Corporation"
+#define IFCVF_DRIVER_NAME "ifcvf"
+
+static irqreturn_t ifcvf_intr_handler(int irq, void *arg)
+{
+ struct vring_info *vring = arg;
+
+ if (vring->cb.callback)
+ return vring->cb.callback(vring->cb.private);
+
+ return IRQ_HANDLED;
+}
+
+static u64 ifcvf_mdev_get_features(struct mdev_device *mdev)
+{
+ return IFC_SUPPORTED_FEATURES;
I would expect this should be done by querying the hw. Or IFC VF can't
get any update through its firmware?
+}
+
+static int ifcvf_mdev_set_features(struct mdev_device *mdev, u64 features)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ vf->req_features = features;
+
+ return 0;
+}
+
+static u64 ifcvf_mdev_get_vq_state(struct mdev_device *mdev, u16 qid)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ return vf->vring[qid].last_avail_idx;
Does this really work? I'd expect it should be fetched from hw since
it's an internal state.
+}
+
+static int ifcvf_mdev_set_vq_state(struct mdev_device *mdev, u16 qid, u64 num)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ vf->vring[qid].last_used_idx = num;
I fail to understand why last_used_idx is needed. It looks to me the
used idx in the used ring is sufficient.
+ vf->vring[qid].last_avail_idx = num;
Do we need a synchronization with hw immediately here?
+
+ return 0;
+}
+
+static int ifcvf_mdev_set_vq_address(struct mdev_device *mdev, u16 idx,
+ u64 desc_area, u64 driver_area,
+ u64 device_area)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ vf->vring[idx].desc = desc_area;
+ vf->vring[idx].avail = driver_area;
+ vf->vring[idx].used = device_area;
+
+ return 0;
+}
+
+static void ifcvf_mdev_set_vq_num(struct mdev_device *mdev, u16 qid, u32 num)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ vf->vring[qid].size = num;
+}
+
+static void ifcvf_mdev_set_vq_ready(struct mdev_device *mdev,
+ u16 qid, bool ready)
+{
+
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ vf->vring[qid].ready = ready;
+}
+
+static bool ifcvf_mdev_get_vq_ready(struct mdev_device *mdev, u16 qid)
+{
+
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ return vf->vring[qid].ready;
+}
+
+static void ifcvf_mdev_set_vq_cb(struct mdev_device *mdev, u16 idx,
+ struct virtio_mdev_callback *cb)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ vf->vring[idx].cb = *cb;
+}
+
+static void ifcvf_mdev_kick_vq(struct mdev_device *mdev, u16 idx)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ ifcvf_notify_queue(vf, idx);
+}
+
+static u8 ifcvf_mdev_get_status(struct mdev_device *mdev)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ return vf->status;
+}
+
+static u32 ifcvf_mdev_get_generation(struct mdev_device *mdev)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ return vf->generation;
+}
+
+static int ifcvf_mdev_get_version(struct mdev_device *mdev)
+{
+ return VIRTIO_MDEV_VERSION;
+}
+
+static u32 ifcvf_mdev_get_device_id(struct mdev_device *mdev)
+{
+ return IFCVF_DEVICE_ID;
+}
+
+static u32 ifcvf_mdev_get_vendor_id(struct mdev_device *mdev)
+{
+ return IFCVF_VENDOR_ID;
+}
+
+static u16 ifcvf_mdev_get_vq_align(struct mdev_device *mdev)
+{
+ return IFCVF_QUEUE_ALIGNMENT;
+}
+
+static int ifcvf_start_datapath(void *private)
+{
+ int i, ret;
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(private);
+
+ for (i = 0; i < (IFCVF_MAX_QUEUE_PAIRS * 2); i++) {
+ if (!vf->vring[i].ready)
+ break;
Looks like error should be returned here?
+
+ if (!vf->vring[i].size)
+ break;
+
+ if (!vf->vring[i].desc || !vf->vring[i].avail ||
+ !vf->vring[i].used)
+ break;
+ }
+ vf->nr_vring = i;
+
+ ret = ifcvf_start_hw(vf);
+ return ret;
+}
+
+static int ifcvf_stop_datapath(void *private)
+{
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(private);
+ int i;
+
+ for (i = 0; i < IFCVF_MAX_QUEUES; i++)
+ vf->vring[i].cb.callback = NULL;
Any synchronization is needed for the vq irq handler?
+
+ ifcvf_stop_hw(vf);
+
+ return 0;
+}
+
+static void ifcvf_reset_vring(struct ifcvf_adapter *adapter)
+{
+ int i;
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+ vf->vring[i].last_used_idx = 0;
+ vf->vring[i].last_avail_idx = 0;
+ vf->vring[i].desc = 0;
+ vf->vring[i].avail = 0;
+ vf->vring[i].used = 0;
+ vf->vring[i].ready = 0;
+ vf->vring->cb.callback = NULL;
+ vf->vring->cb.private = NULL;
+ }
+}
+
+static void ifcvf_mdev_set_status(struct mdev_device *mdev, u8 status)
+{
+ struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+ vf->status = status;
+
+ if (status == 0) {
+ ifcvf_stop_datapath(adapter);
+ ifcvf_reset_vring(adapter);
+ return;
+ }
+
+ if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
+ ifcvf_start_datapath(adapter);
+ return;
+ }
+}
+
+static u16 ifcvf_mdev_get_queue_max(struct mdev_device *mdev)
+{
+ return IFCVF_MAX_QUEUES;
The name is confusing, it was used to return the maximum queue size. In
new version of virtio-mdev, the callback was renamed as get_vq_num_max().
+}
+
+static struct virtio_mdev_device_ops ifc_mdev_ops = {
+ .get_features = ifcvf_mdev_get_features,
+ .set_features = ifcvf_mdev_set_features,
+ .get_status = ifcvf_mdev_get_status,
+ .set_status = ifcvf_mdev_set_status,
+ .get_queue_max = ifcvf_mdev_get_queue_max,
+ .get_vq_state = ifcvf_mdev_get_vq_state,
+ .set_vq_state = ifcvf_mdev_set_vq_state,
+ .set_vq_cb = ifcvf_mdev_set_vq_cb,
+ .set_vq_ready = ifcvf_mdev_set_vq_ready,
+ .get_vq_ready = ifcvf_mdev_get_vq_ready,
+ .set_vq_num = ifcvf_mdev_set_vq_num,
+ .set_vq_address = ifcvf_mdev_set_vq_address,
+ .kick_vq = ifcvf_mdev_kick_vq,
+ .get_generation = ifcvf_mdev_get_generation,
+ .get_version = ifcvf_mdev_get_version,
+ .get_device_id = ifcvf_mdev_get_device_id,
+ .get_vendor_id = ifcvf_mdev_get_vendor_id,
+ .get_vq_align = ifcvf_mdev_get_vq_align,
+};
set_config/get_config is missing. It looks to me they are not hard, just
implementing the access to dev_cfg. It's key to make kernel virtio
driver to work.
And in the new version of virito-mdev, features like _F_LOG_ALL should
be advertised through get_mdev_features.
+
+static int ifcvf_init_msix(struct ifcvf_adapter *adapter)
+{
+ int vector, i, ret, irq;
+ struct pci_dev *pdev = to_pci_dev(adapter->dev);
+ struct ifcvf_hw *vf = &adapter->vf;
+
+ ret = pci_alloc_irq_vectors(pdev, IFCVF_MAX_INTR,
+ IFCVF_MAX_INTR, PCI_IRQ_MSIX);
+ if (ret < 0) {
+ IFC_ERR(adapter->dev, "Failed to alloc irq vectors.\n");
+ return ret;
+ }
+
+ for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+ vector = i + IFCVF_MSI_QUEUE_OFF;
+ irq = pci_irq_vector(pdev, vector);
+ ret = request_irq(irq, ifcvf_intr_handler, 0,
+ pci_name(pdev), &vf->vring[i]);
+ if (ret) {
+ IFC_ERR(adapter->dev,
+ "Failed to request irq for vq %d.\n", i);
+ return ret;
+ }
+ }
Do we need to provide fallback when we can't do per vq MSIX?
+
+ return 0;
+}
+
+static void ifcvf_destroy_adapter(struct ifcvf_adapter *adapter)
+{
+ int i, vector, irq;
+ struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+ struct pci_dev *pdev = to_pci_dev(adapter->dev);
+
+ for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+ vector = i + IFCVF_MSI_QUEUE_OFF;
+ irq = pci_irq_vector(pdev, vector);
+ free_irq(irq, &vf->vring[i]);
+ }
+}
+
+static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ const char *name = "vhost accelerator (virtio ring compatible)";
+
+ return sprintf(buf, "%s\n", name);
+}
+MDEV_TYPE_ATTR_RO(name);
+
+static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
+ char *buf)
+{
+ return sprintf(buf, "%s\n", VIRTIO_MDEV_DEVICE_API_STRING);
+}
+MDEV_TYPE_ATTR_RO(device_api);
+
+static ssize_t available_instances_show(struct kobject *kobj,
+ struct device *dev, char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct ifcvf_adapter *adapter = pci_get_drvdata(pdev);
+
+ return sprintf(buf, "%d\n", adapter->mdev_count);
+}
+
+MDEV_TYPE_ATTR_RO(available_instances);
+
+static ssize_t type_show(struct kobject *kobj,
+ struct device *dev, char *buf)
+{
+ return sprintf(buf, "%s\n", "net");
+}
+
+MDEV_TYPE_ATTR_RO(type);
+
+
+static struct attribute *mdev_types_attrs[] = {
+ &mdev_type_attr_name.attr,
+ &mdev_type_attr_device_api.attr,
+ &mdev_type_attr_available_instances.attr,
+ &mdev_type_attr_type.attr,
+ NULL,
+};
+
+static struct attribute_group mdev_type_group = {
+ .name = "vdpa_virtio",
To be consistent, it should be "vhost" or "virtio".
+ .attrs = mdev_types_attrs,
+};
+
+static struct attribute_group *mdev_type_groups[] = {
+ &mdev_type_group,
+ NULL,
+};
+
+const struct attribute_group *mdev_dev_groups[] = {
+ NULL,
+};
+
+static int ifcvf_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
+{
+ struct device *dev = mdev_parent_dev(mdev);
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct ifcvf_adapter *adapter = pci_get_drvdata(pdev);
+ int ret = 0;
+
+ mutex_lock(&adapter->mdev_lock);
+
+ if (adapter->mdev_count < 1) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ mdev_set_class_id(mdev, MDEV_ID_VHOST);
+ mdev_set_dev_ops(mdev, &ifc_mdev_ops);
+
+ mdev_set_drvdata(mdev, adapter);
+ mdev_set_iommu_device(mdev_dev(mdev), dev);
+
+ INIT_LIST_HEAD(&adapter->dma_maps);
+ adapter->mdev_count--;
+
+out:
+ mutex_unlock(&adapter->mdev_lock);
+ return ret;
+}
+
+static int ifcvf_mdev_remove(struct mdev_device *mdev)
+{
+ struct device *dev = mdev_parent_dev(mdev);
+ struct pci_dev *pdev = to_pci_dev(dev);
+ struct ifcvf_adapter *adapter = pci_get_drvdata(pdev);
+
+ mutex_lock(&adapter->mdev_lock);
+ adapter->mdev_count++;
+ mutex_unlock(&adapter->mdev_lock);
+
+ return 0;
+}
+
+static struct mdev_parent_ops ifcvf_mdev_fops = {
+ .owner = THIS_MODULE,
+ .supported_type_groups = mdev_type_groups,
+ .mdev_attr_groups = mdev_dev_groups,
+ .create = ifcvf_mdev_create,
+ .remove = ifcvf_mdev_remove,
+};
+
+static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+ struct device *dev = &pdev->dev;
+ struct ifcvf_adapter *adapter;
+ struct ifcvf_hw *vf;
+ int ret, i;
+
+ adapter = kzalloc(sizeof(struct ifcvf_adapter), GFP_KERNEL);
+ if (adapter == NULL) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ mutex_init(&adapter->mdev_lock);
+ adapter->mdev_count = 1;
So this is per VF based vDPA implementation, which seems not convenient
for management. Anyhow we can control the creation in PF?
Thanks
+ adapter->dev = dev;
+
+ pci_set_drvdata(pdev, adapter);
+
+ ret = pci_enable_device(pdev);
+ if (ret) {
+ IFC_ERR(adapter->dev, "Failed to enable device.\n");
+ goto free_adapter;
+ }
+
+ ret = pci_request_regions(pdev, IFCVF_DRIVER_NAME);
+ if (ret) {
+ IFC_ERR(adapter->dev, "Failed to request MMIO region.\n");
+ goto disable_device;
+ }
+
+ pci_set_master(pdev);
+
+ ret = ifcvf_init_msix(adapter);
+ if (ret) {
+ IFC_ERR(adapter->dev, "Failed to initialize MSIX.\n");
+ goto free_msix;
+ }
+
+ vf = &adapter->vf;
+ for (i = 0; i < IFCVF_PCI_MAX_RESOURCE; i++) {
+ vf->mem_resource[i].phys_addr = pci_resource_start(pdev, i);
+ vf->mem_resource[i].len = pci_resource_len(pdev, i);
+ if (!vf->mem_resource[i].len) {
+ vf->mem_resource[i].addr = NULL;
+ continue;
+ }
+
+ vf->mem_resource[i].addr = pci_iomap_range(pdev, i, 0,
+ vf->mem_resource[i].len);
+ if (!vf->mem_resource[i].addr) {
+ IFC_ERR(adapter->dev, "Failed to map IO resource %d\n",
+ i);
+ return -1;
+ }
+ }
+
+ if (ifcvf_init_hw(vf, pdev) < 0)
+ return -1;
+
+ ret = mdev_register_device(dev, &ifcvf_mdev_fops);
+ if (ret) {
+ IFC_ERR(adapter->dev, "Failed to register mdev device\n");
+ goto destroy_adapter;
+ }
+
+ return 0;
+
+destroy_adapter:
+ ifcvf_destroy_adapter(adapter);
+free_msix:
+ pci_free_irq_vectors(pdev);
+ pci_release_regions(pdev);
+disable_device:
+ pci_disable_device(pdev);
+free_adapter:
+ kfree(adapter);
+fail:
+ return ret;
+}
+
+static void ifcvf_remove(struct pci_dev *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ifcvf_adapter *adapter = pci_get_drvdata(pdev);
+ struct ifcvf_hw *vf;
+ int i;
+
+ mdev_unregister_device(dev);
+
+ vf = &adapter->vf;
+ for (i = 0; i < IFCVF_PCI_MAX_RESOURCE; i++) {
+ if (vf->mem_resource[i].addr) {
+ pci_iounmap(pdev, vf->mem_resource[i].addr);
+ vf->mem_resource[i].addr = NULL;
+ }
+ }
+
+ ifcvf_destroy_adapter(adapter);
+ pci_free_irq_vectors(pdev);
+
+ pci_release_regions(pdev);
+ pci_disable_device(pdev);
+
+ kfree(adapter);
+}
+
+static struct pci_device_id ifcvf_pci_ids[] = {
+ { PCI_DEVICE_SUB(IFCVF_VENDOR_ID,
+ IFCVF_DEVICE_ID,
+ IFCVF_SUBSYS_VENDOR_ID,
+ IFCVF_SUBSYS_DEVICE_ID) },
+ { 0 },
+};
+MODULE_DEVICE_TABLE(pci, ifcvf_pci_ids);
+
+static struct pci_driver ifcvf_driver = {
+ .name = IFCVF_DRIVER_NAME,
+ .id_table = ifcvf_pci_ids,
+ .probe = ifcvf_probe,
+ .remove = ifcvf_remove,
+};
+
+static int __init ifcvf_init_module(void)
+{
+ int ret;
+
+ ret = pci_register_driver(&ifcvf_driver);
+ return ret;
+}
+
+static void __exit ifcvf_exit_module(void)
+{
+ pci_unregister_driver(&ifcvf_driver);
+}
+
+module_init(ifcvf_init_module);
+module_exit(ifcvf_exit_module);
+
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(VERSION_STRING);
+MODULE_AUTHOR(DRIVER_AUTHOR);