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Message-ID: <0234bb73-4e05-2626-ec57-67454bf204ff@intel.com>
Date: Fri, 18 Oct 2019 14:36:25 +0800
From: "Zhu, Lingshan" <lingshan.zhu@...el.com>
To: Jason Wang <jasowang@...hat.com>, mst@...hat.com,
alex.williamson@...hat.com
Cc: linux-kernel@...r.kernel.org,
virtualization@...ts.linux-foundation.org, kvm@...r.kernel.org,
netdev@...r.kernel.org, dan.daly@...el.com,
cunming.liang@...el.com, tiwei.bie@...el.com, jason.zeng@...el.com,
zhiyuan.lv@...el.com
Subject: Re: [RFC 2/2] vhost: IFC VF vdpa layer
Hello Jason,
Thanks for your comments, I am on a conference travel, I will reply next
Monday.
Thanks,
BR
Zhu Lingshan
On 10/16/2019 6:19 PM, Jason Wang wrote:
>
> On 2019/10/16 上午9:30, 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@...el.com>
>> ---
>> 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);
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