From: Jason Wang <jasow...@redhat.com> This change is a part of XDP offload feature. It handles offloading of eBPF map from the guest.
A command handler for VIRTIO_NET_CTRL_EBPF now checks for subcommand VIRTIO_NET_CTRL_EBPF_MAP and. The control buffer consists of struct virtio_net_ctrl_ebpf_map followed by map key/value or key/key pair. Map manipulation is done using libbpf APIs. Signed-off-by: Jason Wang <jasow...@redhat.com> Co-developed-by: Prashant Bhole <prashantbhole.li...@gmail.com> Signed-off-by: Prashant Bhole <prashantbhole.li...@gmail.com> --- hw/net/Makefile.objs | 2 + hw/net/virtio-net.c | 88 +++++++++++++++++++++ include/standard-headers/linux/virtio_net.h | 23 ++++++ 3 files changed, 113 insertions(+) diff --git a/hw/net/Makefile.objs b/hw/net/Makefile.objs index 7907d2c199..5928497a01 100644 --- a/hw/net/Makefile.objs +++ b/hw/net/Makefile.objs @@ -52,3 +52,5 @@ common-obj-$(CONFIG_ROCKER) += rocker/rocker.o rocker/rocker_fp.o \ obj-$(call lnot,$(CONFIG_ROCKER)) += rocker/qmp-norocker.o common-obj-$(CONFIG_CAN_BUS) += can/ + +virtio-net.o-libs := $(LIBBPF_LIBS) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 7cc1bd1654..3c49273796 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1011,6 +1011,92 @@ static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd, } } +static int virtio_net_handle_ebpf_map(VirtIONet *n, struct iovec *iov, + unsigned int iov_cnt) +{ +#ifdef CONFIG_LIBBPF + struct virtio_net_ctrl_ebpf_map *ctrl = NULL; + struct bpf_create_map_attr map_attr = {}; + uint8_t *key, *val; + uint32_t buf_len; + int fd, err = 0; + size_t s; + + s = iov_to_buf(iov, iov_cnt, 0, &buf_len, sizeof(buf_len)); + if (s != sizeof(buf_len)) { + goto err; + } + + ctrl = malloc(sizeof(*ctrl) + buf_len); + if (!ctrl) { + goto err; + } + + s = iov_to_buf(iov, iov_cnt, 0, ctrl, sizeof(*ctrl) + buf_len); + if (s != (sizeof(*ctrl) + buf_len)) { + error_report("Invalid map control buffer"); + goto err; + } + + key = ctrl->buf; + val = ctrl->buf + ctrl->key_size; + + switch (ctrl->cmd) { + case VIRTIO_NET_BPF_CMD_CREATE_MAP: + map_attr.map_type = ctrl->map_type; + map_attr.map_flags = ctrl->map_flags; + map_attr.key_size = ctrl->key_size; + map_attr.value_size = ctrl->value_size; + map_attr.max_entries = ctrl->max_entries; + fd = bpf_create_map_xattr(&map_attr); + if (fd < 0) { + goto err; + } + ctrl->map_fd = fd; + break; + case VIRTIO_NET_BPF_CMD_FREE_MAP: + close(ctrl->map_fd); + break; + case VIRTIO_NET_BPF_CMD_LOOKUP_ELEM: + err = bpf_map_lookup_elem(ctrl->map_fd, key, val); + break; + case VIRTIO_NET_BPF_CMD_GET_FIRST: + err = bpf_map_get_next_key(ctrl->map_fd, NULL, val); + break; + case VIRTIO_NET_BPF_CMD_GET_NEXT: + err = bpf_map_get_next_key(ctrl->map_fd, key, val); + break; + case VIRTIO_NET_BPF_CMD_UPDATE_ELEM: + err = bpf_map_update_elem(ctrl->map_fd, key, val, ctrl->flags); + break; + case VIRTIO_NET_BPF_CMD_DELETE_ELEM: + err = bpf_map_delete_elem(ctrl->map_fd, key); + default: + error_report("map operation not implemented %d", ctrl->cmd); + goto err; + } + + if (err) { + goto err; + } + + s = iov_from_buf(iov, iov_cnt, 0, ctrl, sizeof(*ctrl) + buf_len); + if (s != sizeof(*ctrl) + buf_len) { + error_report("failed to write map operation result"); + goto err; + } + + free(ctrl); + return VIRTIO_NET_OK; + +err: + if (ctrl) { + free(ctrl); + } +#endif + return VIRTIO_NET_ERR; +} + static int virtio_net_handle_ebpf_prog(VirtIONet *n, struct iovec *iov, unsigned int iov_cnt) { @@ -1053,6 +1139,8 @@ static int virtio_net_handle_ebpf(VirtIONet *n, uint8_t cmd, { if (cmd == VIRTIO_NET_CTRL_EBPF_PROG) { return virtio_net_handle_ebpf_prog(n, iov, iov_cnt); + } else if (cmd == VIRTIO_NET_CTRL_EBPF_MAP) { + return virtio_net_handle_ebpf_map(n, iov, iov_cnt); } return VIRTIO_NET_ERR; diff --git a/include/standard-headers/linux/virtio_net.h b/include/standard-headers/linux/virtio_net.h index 83292c81bc..cca234e0e8 100644 --- a/include/standard-headers/linux/virtio_net.h +++ b/include/standard-headers/linux/virtio_net.h @@ -281,11 +281,34 @@ struct virtio_net_ctrl_ebpf_prog { uint8_t insns[0]; }; +struct virtio_net_ctrl_ebpf_map { + __virtio32 buf_len; + __virtio32 cmd; + __virtio32 map_type; + __virtio32 key_size; + __virtio32 value_size; + __virtio32 max_entries; + __virtio32 map_flags; + __virtio32 map_fd; + __virtio64 flags; + uint8_t buf[0]; +}; + #define VIRTIO_NET_CTRL_EBPF 6 #define VIRTIO_NET_CTRL_EBPF_PROG 1 + #define VIRTIO_NET_CTRL_EBPF_MAP 2 /* Commands for VIRTIO_NET_CTRL_EBPF_PROG */ #define VIRTIO_NET_BPF_CMD_SET_OFFLOAD 1 #define VIRTIO_NET_BPF_CMD_UNSET_OFFLOAD 2 +/* Commands for VIRTIO_NET_CTRL_EBPF_MAP */ +#define VIRTIO_NET_BPF_CMD_CREATE_MAP 1 +#define VIRTIO_NET_BPF_CMD_FREE_MAP 2 +#define VIRTIO_NET_BPF_CMD_UPDATE_ELEM 3 +#define VIRTIO_NET_BPF_CMD_LOOKUP_ELEM 4 +#define VIRTIO_NET_BPF_CMD_DELETE_ELEM 5 +#define VIRTIO_NET_BPF_CMD_GET_FIRST 6 +#define VIRTIO_NET_BPF_CMD_GET_NEXT 7 + #endif /* _LINUX_VIRTIO_NET_H */ -- 2.20.1