Re: [PATCH v1] vdpa/vp_vdpa : add vdpa tool support in vp_vdpa

[Cindy Lu <lulu@redhat.com>]

On Wed, Apr 20, 2022 at 2:27 PM Cindy Lu <lulu@redhat.com> wrote:
>
>
>
> On Wed, Apr 20, 2022 at 11:21 AM Jason Wang <jasowang@redhat.com> wrote:
>>
>>
>> 在 2022/4/19 09:40, Cindy Lu 写道:
>> > this patch is to add the support for vdpa tool in vp_vdpa
>> > here is the example steps
>> > modprobe vp_vdpa
>> > modprobe vhost_vdpa
>> >
>> > echo 0000:00:06.0>/sys/bus/pci/drivers/virtio-pci/unbind
>> > echo 1af4 1041 > /sys/bus/pci/drivers/vp-vdpa/new_id
>> >
>> > vdpa dev add name vdpa1 mgmtdev pci/0000:00:06.0
>> >
>> > Signed-off-by: Cindy Lu <lulu@redhat.com>
>> > ---
>> >   drivers/vdpa/virtio_pci/vp_vdpa.c | 86 ++++++++++++++++++++++++++++---
>> >   1 file changed, 78 insertions(+), 8 deletions(-)
>> >
>> > diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
>> > index cce101e6a940..d8a1d2f8e9bb 100644
>> > --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
>> > +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
>> > @@ -17,6 +17,8 @@
>> >   #include <linux/virtio_ring.h>
>> >   #include <linux/virtio_pci.h>
>> >   #include <linux/virtio_pci_modern.h>
>> > +#include <uapi/linux/virtio_net.h>
>> > +#include <uapi/linux/vdpa.h>
>> >
>> >   #define VP_VDPA_QUEUE_MAX 256
>> >   #define VP_VDPA_DRIVER_NAME "vp_vdpa"
>> > @@ -41,6 +43,18 @@ struct vp_vdpa {
>> >       int vectors;
>> >   };
>> >
>> > +struct vp_vdpa_mgmtdev {
>> > +     struct vdpa_mgmt_dev mgtdev;
>> > +     struct vp_vdpa *vp_vdpa;
>> > +     struct pci_dev *pdev;
>> > +};
>> > +
>> > +#define VP_VDPA_NET_FEATURES                                                   \
>> > +     ((1ULL << VIRTIO_F_ANY_LAYOUT) | (1ULL << VIRTIO_F_VERSION_1) |        \
>> > +      (1ULL << VIRTIO_F_ACCESS_PLATFORM))
>> > +
>> > +#define VP_VDPA_NET_VQ_NUM 2
>>
>>
>> Let's not go backwards, e.g we've already support any kind of virtio
>> device with any kind of features. see the comment in vp_vdpa_probe().
>>
>>
> got it, I will fix this
>>
>> > +
>> >   static struct vp_vdpa *vdpa_to_vp(struct vdpa_device *vdpa)
>> >   {
>> >       return container_of(vdpa, struct vp_vdpa, vdpa);
>> > @@ -454,9 +468,14 @@ 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)
>> > +static int vp_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
>> > +                        const struct vdpa_dev_set_config *add_config)
>> >   {
>> > +     struct vp_vdpa_mgmtdev *vp_vdpa_mgtdev =
>> > +             container_of(v_mdev, struct vp_vdpa_mgmtdev, mgtdev);
>> > +
>> >       struct virtio_pci_modern_device *mdev;
>> > +     struct pci_dev *pdev = vp_vdpa_mgtdev->pdev;
>> >       struct device *dev = &pdev->dev;
>> >       struct vp_vdpa *vp_vdpa;
>> >       int ret, i;
>> > @@ -465,8 +484,9 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> >       if (ret)
>> >               return ret;
>> >
>> > -     vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
>> > -                                 dev, &vp_vdpa_ops, NULL, false);
>> > +     vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa, dev, &vp_vdpa_ops,
>> > +                                 name, false);
>>
>>
>> Nit: let's keep the line of vdpa_alloc_device() unchanged to reduce the
>> changeset.
>>
>>
> will fix this
>>
>> > +
>> >       if (IS_ERR(vp_vdpa)) {
>> >               dev_err(dev, "vp_vdpa: Failed to allocate vDPA structure\n");
>> >               return PTR_ERR(vp_vdpa);
>> > @@ -480,9 +500,10 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> >               dev_err(&pdev->dev, "Failed to probe modern PCI device\n");
>> >               goto err;
>> >       }
>> > +     vp_vdpa_mgtdev->vp_vdpa = vp_vdpa;
>> >
>> >       pci_set_master(pdev);
>> > -     pci_set_drvdata(pdev, vp_vdpa);
>> > +     pci_set_drvdata(pdev, vp_vdpa_mgtdev);
>> >
>> >       vp_vdpa->vdpa.dma_dev = &pdev->dev;
>> >       vp_vdpa->queues = vp_modern_get_num_queues(mdev);
>> > @@ -516,7 +537,8 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> >       }
>> >       vp_vdpa->config_irq = VIRTIO_MSI_NO_VECTOR;
>> >
>> > -     ret = vdpa_register_device(&vp_vdpa->vdpa, vp_vdpa->queues);
>> > +     vp_vdpa->vdpa.mdev = &vp_vdpa_mgtdev->mgtdev;
>> > +     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;
>> > @@ -529,12 +551,60 @@ static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> >       return ret;
>> >   }
>> >
>> > -static void vp_vdpa_remove(struct pci_dev *pdev)
>> > +static void vp_vdpa_dev_del(struct vdpa_mgmt_dev *v_mdev,
>> > +                         struct vdpa_device *dev)
>> >   {
>> > -     struct vp_vdpa *vp_vdpa = pci_get_drvdata(pdev);
>> > +     struct vp_vdpa_mgmtdev *vp_vdpa_mgtdev =
>> > +             container_of(v_mdev, struct vp_vdpa_mgmtdev, mgtdev);
>> > +
>> > +     struct vp_vdpa *vp_vdpa = vp_vdpa_mgtdev->vp_vdpa;
>> >
>> >       vp_modern_remove(&vp_vdpa->mdev);
>> > -     vdpa_unregister_device(&vp_vdpa->vdpa);
>> > +     _vdpa_unregister_device(&vp_vdpa->vdpa);
>> > +     vp_vdpa_mgtdev->vp_vdpa = NULL;
>> > +}
>> > +
>> > +static const struct vdpa_mgmtdev_ops vp_vdpa_mdev_ops = {
>> > +     .dev_add = vp_vdpa_dev_add,
>> > +     .dev_del = vp_vdpa_dev_del,
>> > +};
>> > +
>> > +static struct virtio_device_id vp_vdpa_id_table[] = {
>> > +     { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
>> > +     { 0 },
>> > +};
>>
>>
>> Let's not limit the vp_vdpa to net, it can support all other virtio devices.
>>
>>
> sure, will fix this
>>
>> > +
>> > +static int vp_vdpa_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>> > +{
>> > +     struct vp_vdpa_mgmtdev *vp_vdpa_mgtdev;
>> > +     struct vdpa_mgmt_dev *mgtdev;
>> > +     struct device *dev = &pdev->dev;
>> > +     int err;
>> > +
>> > +     vp_vdpa_mgtdev = kzalloc(sizeof(*vp_vdpa_mgtdev), GFP_KERNEL);
>> > +     if (!vp_vdpa_mgtdev)
>> > +             return -ENOMEM;
>> > +     mgtdev = &vp_vdpa_mgtdev->mgtdev;
>> > +
>> > +     mgtdev->ops = &vp_vdpa_mdev_ops;
>> > +     mgtdev->device = dev;
>> > +     mgtdev->id_table = vp_vdpa_id_table;
>> > +     vp_vdpa_mgtdev->pdev = pdev;
>> > +
>> > +     mgtdev->max_supported_vqs = VP_VDPA_NET_VQ_NUM;
>>
>>
>> Let's read this from the device instead of using the hard-coded value.
>>
>>
>> > +     mgtdev->supported_features = VP_VDPA_NET_FEATURES;
>>
>>
>> Let's read this from the device.
>>
> sure will fix this
HI Jason, I have check the code, maybe we can't read these
informations from device here,
because the  virtio_pci_modern_device   was inited in vp_vdpa_dev_add(),
if we want to read these information in vp_vdpa_probe(). maybe we need
to change the struct in vp_vdpa. and separate the
struct virtio_pci_modern_device  from struct vp_vdpa. I'm not sure if
this is ok to do?

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;
};
Thanks
cindy
>>
>>
>> > +
>> > +     err = vdpa_mgmtdev_register(mgtdev);
>>
>>
>> Do we need to free the vp_vdpa_mgtdev here?
>>
> will add the this
>>
>> Thanks
>>
>>
>> > +
>> > +     return err;
>> > +}
>> > +
>> > +static void vp_vdpa_remove(struct pci_dev *pdev)
>> > +{
>> > +     struct vp_vdpa_mgmtdev *vp_vdpa_mgtdev = pci_get_drvdata(pdev);
>> > +
>> > +     vdpa_mgmtdev_unregister(&vp_vdpa_mgtdev->mgtdev);
>> > +     kfree(vp_vdpa_mgtdev);
>> >   }
>> >
>> >   static struct pci_driver vp_vdpa_driver = {
>>