On Fri, Dec 10, 2021 at 5:51 AM Si-Wei Liu <si-wei.liu@xxxxxxxxxx> wrote:
>
>
>
> On 12/8/2021 9:36 PM, Jason Wang wrote:
> > On Thu, Dec 9, 2021 at 8:25 AM Si-Wei Liu <si-wei.liu@xxxxxxxxxx> wrote:
> >>
> >>
> >> On 12/8/2021 12:14 PM, Eli Cohen wrote:
> >>> Add netlink support to configure the max virtqueue pairs for a device.
> >>> At least one pair is required. The maximum is dictated by the device.
> >>>
> >>> Example:
> >>>
> >>> $ vdpa dev add name vdpa-a mgmtdev auxiliary/mlx5_core.sf.1 max_vqp 5
> >> Not this patch, but I think there should be a mega attribute defined
> >> ahead to specify the virtio class/type to create vdpa instance with.
> >> Like the existing ones e.g. mac_addr and mtu, max_vqp is also vdpa net
> >> specific attribute.
> > Probably, but this only works for the case when a single parent is
> > allowed to create different types of devices. It looks to me the
> > current model to have a per type parent.
> Yes, that is the current situation and implementation, although the
> model does allow multi-type parent through
> VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES.
Right, so I agree with you, we need to specify the class first.
> Regardless, even though with
> single-type parent, so far on vdpa creation there's no validation done
> yet against which class/type the parent can support. The max-vqp is
> essentially vdpa network device only, but command line users don't have
> a means to infer it is structured this way, and/or which vdpa parent may
> support this config attribute. That said, were the command line usage
> structured like below, I would have less worry.
>
> $ vdpa dev add name vdpa-a mgmtdev auxiliary/mlx5_core.sf.1 net.max_vqp 5
It might be easier to specify class as a dedicated parameter, since we
may want to specify mtu and mac.
Thanks
>
> Alternatively, if the goal is to keep the attribute flat, we may show
> the mapping for the parent capability and the supported class:
>
> $ vdpa mgmtdev capab show
> pci/0000:41:00.2:
> class: net
> mac: off
> mtu: on
> max_mtu: 9000
> max_vqp: 1
> auxiliary/mlx5_core.sf.1:
> class: net
> mac: on
> mtu: off
> max_mtu: 1500
> max_vqp: 256
>
> Thanks,
> -Siwei
>
> >
> > Thanks
> >
> >> -Siwei
> >>
> >>> Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
> >>> ---
> >>> v0 -> v1:
> >>> 1. fix typo
> >>> 2. move max_vq_pairs to net specific struct
> >>>
> >>> drivers/vdpa/vdpa.c | 14 +++++++++++++-
> >>> include/linux/vdpa.h | 1 +
> >>> 2 files changed, 14 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> >>> index c37d384c0f33..3bf016e03512 100644
> >>> --- a/drivers/vdpa/vdpa.c
> >>> +++ b/drivers/vdpa/vdpa.c
> >>> @@ -480,7 +480,8 @@ vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
> >>> }
> >>>
> >>> #define VDPA_DEV_NET_ATTRS_MASK ((1 << VDPA_ATTR_DEV_NET_CFG_MACADDR) | \
> >>> - (1 << VDPA_ATTR_DEV_NET_CFG_MTU))
> >>> + (1 << VDPA_ATTR_DEV_NET_CFG_MTU) | \
> >>> + (1 << VDPA_ATTR_DEV_NET_CFG_MAX_VQP))
> >>>
> >>> static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)
> >>> {
> >>> @@ -506,6 +507,17 @@ static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *i
> >>> nla_get_u16(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]);
> >>> config.mask |= (1 << VDPA_ATTR_DEV_NET_CFG_MTU);
> >>> }
> >>> + if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MAX_VQP]) {
> >>> + config.net.max_vq_pairs =
> >>> + nla_get_u16(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MAX_VQP]);
> >>> + if (!config.net.max_vq_pairs) {
> >>> + NL_SET_ERR_MSG_MOD(info->extack,
> >>> + "At least one pair of VQs is required");
> >>> + err = -EINVAL;
> >>> + goto err;
> >>> + }
> >>> + config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP);
> >>> + }
> >>>
> >>> /* Skip checking capability if user didn't prefer to configure any
> >>> * device networking attributes. It is likely that user might have used
> >>> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> >>> index db24317d61b6..b62032573780 100644
> >>> --- a/include/linux/vdpa.h
> >>> +++ b/include/linux/vdpa.h
> >>> @@ -99,6 +99,7 @@ struct vdpa_dev_set_config {
> >>> struct {
> >>> u8 mac[ETH_ALEN];
> >>> u16 mtu;
> >>> + u16 max_vq_pairs;
> >>> } net;
> >>> u64 mask;
> >>> };
>
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