On Tue, Sep 23, 2025 at 09:19:13AM -0500, Daniel Jurgens wrote:
> When probing a virtnet device, attempt to read the flow filter
> capabilities. In order to use the feature the caps must also
> be set. For now setting what was read is sufficient.
>
> Signed-off-by: Daniel Jurgens <[email protected]>
> Reviewed-by: Parav Pandit <[email protected]>
> Reviewed-by: Shahar Shitrit <[email protected]>
> ---
> drivers/net/virtio_net/Makefile | 2 +-
> drivers/net/virtio_net/virtio_net_ff.c | 145 +++++++++++++++++++++++
> drivers/net/virtio_net/virtio_net_ff.h | 22 ++++
> drivers/net/virtio_net/virtio_net_main.c | 7 ++
> include/linux/virtio_admin.h | 1 +
> include/uapi/linux/virtio_net_ff.h | 55 +++++++++
> 6 files changed, 231 insertions(+), 1 deletion(-)
> create mode 100644 drivers/net/virtio_net/virtio_net_ff.c
> create mode 100644 drivers/net/virtio_net/virtio_net_ff.h
> create mode 100644 include/uapi/linux/virtio_net_ff.h
>
> diff --git a/drivers/net/virtio_net/Makefile b/drivers/net/virtio_net/Makefile
> index c0a4725ddd69..c41a587ffb5b 100644
> --- a/drivers/net/virtio_net/Makefile
> +++ b/drivers/net/virtio_net/Makefile
> @@ -5,4 +5,4 @@
>
> obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
>
> -virtio_net-objs := virtio_net_main.o
> +virtio_net-objs := virtio_net_main.o virtio_net_ff.o
> diff --git a/drivers/net/virtio_net/virtio_net_ff.c
> b/drivers/net/virtio_net/virtio_net_ff.c
> new file mode 100644
> index 000000000000..61cb45331c97
> --- /dev/null
> +++ b/drivers/net/virtio_net/virtio_net_ff.c
> @@ -0,0 +1,145 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <linux/virtio_admin.h>
> +#include <linux/virtio.h>
> +#include <net/ipv6.h>
> +#include <net/ip.h>
> +#include "virtio_net_ff.h"
> +
> +static size_t get_mask_size(u16 type)
> +{
> + switch (type) {
> + case VIRTIO_NET_FF_MASK_TYPE_ETH:
> + return sizeof(struct ethhdr);
> + case VIRTIO_NET_FF_MASK_TYPE_IPV4:
> + return sizeof(struct iphdr);
> + case VIRTIO_NET_FF_MASK_TYPE_IPV6:
> + return sizeof(struct ipv6hdr);
> + case VIRTIO_NET_FF_MASK_TYPE_TCP:
> + return sizeof(struct tcphdr);
> + case VIRTIO_NET_FF_MASK_TYPE_UDP:
> + return sizeof(struct udphdr);
> + }
> +
> + return 0;
> +}
> +
> +void virtnet_ff_init(struct virtnet_ff *ff, struct virtio_device *vdev)
> +{
> + struct virtio_admin_cmd_query_cap_id_result *cap_id_list __free(kfree)
> = NULL;
> + size_t ff_mask_size = sizeof(struct virtio_net_ff_cap_mask_data) +
> + sizeof(struct virtio_net_ff_selector) *
> + VIRTIO_NET_FF_MASK_TYPE_MAX;
> + struct virtio_net_ff_selector *sel;
> + int err;
> + int i;
> +
> + cap_id_list = kzalloc(sizeof(*cap_id_list), GFP_KERNEL);
> + if (!cap_id_list)
> + return;
> +
> + err = virtio_device_cap_id_list_query(vdev, cap_id_list);
> + if (err)
> + return;
> +
> + if (!(VIRTIO_CAP_IN_LIST(cap_id_list,
> + VIRTIO_NET_FF_RESOURCE_CAP) &&
> + VIRTIO_CAP_IN_LIST(cap_id_list,
> + VIRTIO_NET_FF_SELECTOR_CAP) &&
> + VIRTIO_CAP_IN_LIST(cap_id_list,
> + VIRTIO_NET_FF_ACTION_CAP)))
> + return;
> +
> + ff->ff_caps = kzalloc(sizeof(*ff->ff_caps), GFP_KERNEL);
> + if (!ff->ff_caps)
> + return;
> +
> + err = virtio_device_cap_get(vdev,
> + VIRTIO_NET_FF_RESOURCE_CAP,
> + ff->ff_caps,
> + sizeof(*ff->ff_caps));
> +
> + if (err)
> + goto err_ff;
> +
> + /* VIRTIO_NET_FF_MASK_TYPE start at 1 */
> + for (i = 1; i <= VIRTIO_NET_FF_MASK_TYPE_MAX; i++)
> + ff_mask_size += get_mask_size(i);
> +
> + ff->ff_mask = kzalloc(ff_mask_size, GFP_KERNEL);
> + if (!ff->ff_mask)
> + goto err_ff;
> +
> + err = virtio_device_cap_get(vdev,
> + VIRTIO_NET_FF_SELECTOR_CAP,
> + ff->ff_mask,
> + ff_mask_size);
> +
> + if (err)
> + goto err_ff_mask;
> +
> + ff->ff_actions = kzalloc(sizeof(*ff->ff_actions) +
> + VIRTIO_NET_FF_ACTION_MAX,
> + GFP_KERNEL);
> + if (!ff->ff_actions)
> + goto err_ff_mask;
> +
> + err = virtio_device_cap_get(vdev,
> + VIRTIO_NET_FF_ACTION_CAP,
> + ff->ff_actions,
> + sizeof(*ff->ff_actions) +
> VIRTIO_NET_FF_ACTION_MAX);
> +
> + if (err)
> + goto err_ff_action;
> +
> + err = virtio_device_cap_set(vdev,
> + VIRTIO_NET_FF_RESOURCE_CAP,
> + ff->ff_caps,
> + sizeof(*ff->ff_caps));
> + if (err)
> + goto err_ff_action;
> +
> + ff_mask_size = sizeof(struct virtio_net_ff_cap_mask_data);
> + sel = &ff->ff_mask->selectors[0];
> +
> + for (int i = 0; i < ff->ff_mask->count; i++) {
I do not think kernel style allows this int inside loop.
I think you need to declare it at the beginning of the block.
> + ff_mask_size += sizeof(struct virtio_net_ff_selector) +
> sel->length;
> + sel = (struct virtio_net_ff_selector *)((u8 *)sel +
> sizeof(*sel) + sel->length);
> + }
> +
> + err = virtio_device_cap_set(vdev,
> + VIRTIO_NET_FF_SELECTOR_CAP,
> + ff->ff_mask,
> + ff_mask_size);
> + if (err)
> + goto err_ff_action;
> +
> + err = virtio_device_cap_set(vdev,
> + VIRTIO_NET_FF_ACTION_CAP,
> + ff->ff_actions,
> + sizeof(*ff->ff_actions) +
> VIRTIO_NET_FF_ACTION_MAX);
> + if (err)
> + goto err_ff_action;
> +
> + ff->vdev = vdev;
> + ff->ff_supported = true;
> +
> + return;
> +
> +err_ff_action:
> + kfree(ff->ff_actions);
> +err_ff_mask:
> + kfree(ff->ff_mask);
> +err_ff:
> + kfree(ff->ff_caps);
> +}
> +
> +void virtnet_ff_cleanup(struct virtnet_ff *ff)
> +{
> + if (!ff->ff_supported)
> + return;
> +
> + kfree(ff->ff_actions);
> + kfree(ff->ff_mask);
> + kfree(ff->ff_caps);
> +}
> diff --git a/drivers/net/virtio_net/virtio_net_ff.h
> b/drivers/net/virtio_net/virtio_net_ff.h
> new file mode 100644
> index 000000000000..4aac0bd08b63
> --- /dev/null
> +++ b/drivers/net/virtio_net/virtio_net_ff.h
> @@ -0,0 +1,22 @@
> +/* SPDX-License-Identifier: GPL-2.0-only
> + *
> + * Header file for virtio_net flow filters
> + */
> +#include <linux/virtio_admin.h>
> +
> +#ifndef _VIRTIO_NET_FF_H
> +#define _VIRTIO_NET_FF_H
> +
> +struct virtnet_ff {
> + struct virtio_device *vdev;
> + bool ff_supported;
> + struct virtio_net_ff_cap_data *ff_caps;
> + struct virtio_net_ff_cap_mask_data *ff_mask;
> + struct virtio_net_ff_actions *ff_actions;
> +};
> +
> +void virtnet_ff_init(struct virtnet_ff *ff, struct virtio_device *vdev);
> +
> +void virtnet_ff_cleanup(struct virtnet_ff *ff);
> +
> +#endif /* _VIRTIO_NET_FF_H */
> diff --git a/drivers/net/virtio_net/virtio_net_main.c
> b/drivers/net/virtio_net/virtio_net_main.c
> index 7da5a37917e9..ebf3e5db0d64 100644
> --- a/drivers/net/virtio_net/virtio_net_main.c
> +++ b/drivers/net/virtio_net/virtio_net_main.c
> @@ -26,6 +26,7 @@
> #include <net/netdev_rx_queue.h>
> #include <net/netdev_queues.h>
> #include <net/xdp_sock_drv.h>
> +#include "virtio_net_ff.h"
>
> static int napi_weight = NAPI_POLL_WEIGHT;
> module_param(napi_weight, int, 0444);
> @@ -493,6 +494,8 @@ struct virtnet_info {
> struct failover *failover;
>
> u64 device_stats_cap;
> +
> + struct virtnet_ff ff;
> };
>
> struct padded_vnet_hdr {
> @@ -7116,6 +7119,8 @@ static int virtnet_probe(struct virtio_device *vdev)
> }
> vi->guest_offloads_capable = vi->guest_offloads;
>
> + virtnet_ff_init(&vi->ff, vi->vdev);
> +
> rtnl_unlock();
>
> err = virtnet_cpu_notif_add(vi);
> @@ -7131,6 +7136,7 @@ static int virtnet_probe(struct virtio_device *vdev)
>
> free_unregister_netdev:
> unregister_netdev(dev);
> + virtnet_ff_cleanup(&vi->ff);
> free_failover:
> net_failover_destroy(vi->failover);
> free_vqs:
> @@ -7180,6 +7186,7 @@ static void virtnet_remove(struct virtio_device *vdev)
> virtnet_free_irq_moder(vi);
>
> unregister_netdev(vi->dev);
> + virtnet_ff_cleanup(&vi->ff);
>
> net_failover_destroy(vi->failover);
>
> diff --git a/include/linux/virtio_admin.h b/include/linux/virtio_admin.h
> index cc6b82461c9f..f8f1369d1175 100644
> --- a/include/linux/virtio_admin.h
> +++ b/include/linux/virtio_admin.h
> @@ -3,6 +3,7 @@
> * Header file for virtio admin operations
> */
> #include <uapi/linux/virtio_pci.h>
> +#include <uapi/linux/virtio_net_ff.h>
>
> #ifndef _LINUX_VIRTIO_ADMIN_H
> #define _LINUX_VIRTIO_ADMIN_H
> diff --git a/include/uapi/linux/virtio_net_ff.h
> b/include/uapi/linux/virtio_net_ff.h
> new file mode 100644
> index 000000000000..a35533bf8377
> --- /dev/null
> +++ b/include/uapi/linux/virtio_net_ff.h
> @@ -0,0 +1,55 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
> + *
> + * Header file for virtio_net flow filters
> + */
> +#ifndef _LINUX_VIRTIO_NET_FF_H
> +#define _LINUX_VIRTIO_NET_FF_H
> +
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +
> +#define VIRTIO_NET_FF_RESOURCE_CAP 0x800
> +#define VIRTIO_NET_FF_SELECTOR_CAP 0x801
> +#define VIRTIO_NET_FF_ACTION_CAP 0x802
> +
> +struct virtio_net_ff_cap_data {
> + __le32 groups_limit;
> + __le32 classifiers_limit;
> + __le32 rules_limit;
> + __le32 rules_per_group_limit;
> + __u8 last_rule_priority;
> + __u8 selectors_per_classifier_limit;
> +};
> +
> +struct virtio_net_ff_selector {
> + __u8 type;
> + __u8 flags;
> + __u8 reserved[2];
> + __u8 length;
> + __u8 reserved1[3];
> + __u8 mask[];
> +};
> +
> +#define VIRTIO_NET_FF_MASK_TYPE_ETH 1
> +#define VIRTIO_NET_FF_MASK_TYPE_IPV4 2
> +#define VIRTIO_NET_FF_MASK_TYPE_IPV6 3
> +#define VIRTIO_NET_FF_MASK_TYPE_TCP 4
> +#define VIRTIO_NET_FF_MASK_TYPE_UDP 5
> +#define VIRTIO_NET_FF_MASK_TYPE_MAX VIRTIO_NET_FF_MASK_TYPE_UDP
> +
> +struct virtio_net_ff_cap_mask_data {
> + __u8 count;
> + __u8 reserved[7];
> + struct virtio_net_ff_selector selectors[];
> +};
> +#define VIRTIO_NET_FF_MASK_F_PARTIAL_MASK (1 << 0)
> +
> +#define VIRTIO_NET_FF_ACTION_DROP 1
> +#define VIRTIO_NET_FF_ACTION_RX_VQ 2
> +#define VIRTIO_NET_FF_ACTION_MAX VIRTIO_NET_FF_ACTION_RX_VQ
> +struct virtio_net_ff_actions {
> + __u8 count;
> + __u8 reserved[7];
> + __u8 actions[];
> +};
> +#endif
> --
> 2.45.0
