Re: [RFC 2/2] vhost: IFC VF vdpa layer

["Zhu, Lingshan" <lingshan.zhu@intel.com>]

On 10/22/2019 2:53 PM, Zhu Lingshan wrote:
>
> On 10/21/2019 6:19 PM, Jason Wang wrote:
>>
>> On 2019/10/21 下午5:53, Zhu, Lingshan wrote:
>>>
>>> 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@intel.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?
>>>
>>> Hi Jason,
>>>
>>> Thanks for your comments, for now driver just support these features.
>>
>>
>> Ok, it should work but less flexible, we can change it in the future.
> sure!
>>
>>
>>>
>>>>
>>>>
>>>>> +}
>>>>> +
>>>>> +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.
>>> for now, it's working, we intend to support LM in next version drivers.
>>
>>
>> I'm not sure I understand here, I don't see any synchronization 
>> between the hardware and last_avail_idx, so last_avail_idx should not 
>> change.
>>
>> Btw, what did "LM" mean :) ?
>
> I can add bar IO operations here, LM = live migration, sorry for the 
> abbreviation.
>
>>
>>
>>>>
>>>>
>>>>> +}
>>>>> +
>>>>> +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.
>>> I will remove it.
>>>>
>>>>
>>>>> + 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?
>>> agreed!
>>>>
>>>>
>>>>> +
>>>>> +        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?
>>> I think even we set callback = NULL, the code is still there, 
>>> on-going routines would not be effected.
>>
>>
>> Ok I think you mean when ifcvf_stop_hw() return, hardware will not 
>> respond to e.g kick and other events etc.
> Yes, ifcvf_stop_hw() would disable the hw.
>>
>>
>>>>
>>>>
>>>>> +
>>>>> +    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().
>>> will change that.
>>>>
>>>>
>>>>> +}
>>>>> +
>>>>> +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.
>>> IMHO, currently the driver can work without set/get_config, 
>>> vhost_mdev doesn't call them for now.
>>
>>
>> Yes, but it was required by virtio_mdev for host driver to work, and 
>> it looks to me it's not hard to add them. If possible please add them 
>> and "virtio" type then we can use the ops for both the case of VM and 
>> containers.
> sure

Hello Jason,

Just want to double confirm the implementation of set/get_config, for 
now, dev_cfg only contains mac[6], status and max_virtqueue_pairs, is 
that enough to support virtio_mdev?

THanks!

>>
>>
>>>>
>>>>
>>>>> +
>>>>> +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?
>>> I think it would be very rarely that can not get enough vectors.
>>
>>
>> Right.
>>
>>
>>>>
>>>>
>>>>> +
>>>>> +    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".
>>> agreed!
>>>>
>>>>
>>>>> +    .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
>>> the driver scope for now doesn't support that, we can add these 
>>> feature in next releases.
>>
>>
>> Not a must for this series, but to have a better interaction with 
>> management like libvirt, it's better.
>>
>> Btw, do you have the plan to post PF drivers?
>>
>> Thanks
> Maybe we can workout PF driver in next release :)
> THanks,
> BR
> Zhu Lingshan
>>
>>