diff options
Diffstat (limited to 'share/man/man4/vtnet.4')
| -rw-r--r-- | share/man/man4/vtnet.4 | 173 |
1 files changed, 164 insertions, 9 deletions
diff --git a/share/man/man4/vtnet.4 b/share/man/man4/vtnet.4 index 8b99cd9f17b9..fd41b36882a6 100644 --- a/share/man/man4/vtnet.4 +++ b/share/man/man4/vtnet.4 @@ -22,7 +22,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd July 29, 2025 +.Dd September 30, 2025 .Dt VTNET 4 .Os .Sh NAME @@ -54,6 +54,20 @@ TCP segmentation offload (TSO), TCP large receive offload (LRO), hardware VLAN tag stripping/insertion features, a multicast hash filter, as well as Jumbo Frames (up to 9216 bytes), which can be configured via the interface MTU setting. +.Pp +Two flavors of TCP LRO are supported: +Hardware TCP LRO, which is performed by the host providing TCP segments larger +than the MTU to the guest, and Software TCP LRO, which is performed by the +network stack of the guest processing TCP segments in an optimized way. +Only one flavour of TCP LRO should be used. +Since hardware TCP LRO can have bad interactions with IP forwarding and +software TCP LRO mitigates several drawbacks of hardware TCP LRO, the default +setting is to disable hardware TCP LRO. +See the loader tunable +.Va hw.vtnet. Ns Ar X Ns Va .lro_disable . +.Pp +TCP/UDP receive checksum offload cannot be configured independently for IPv4 +and IPv6. Selecting an MTU larger than 1500 bytes with the .Xr ifconfig 8 utility configures the adapter to receive and transmit Jumbo Frames. @@ -68,21 +82,32 @@ prompt before booting the kernel or stored in .Bl -tag -width "xxxxxx" .It Va hw.vtnet.csum_disable .It Va hw.vtnet. Ns Ar X Ns Va .csum_disable -This tunable disables receive and send checksum offload. +This tunable disables receive and transmit checksum offloading for TCP and +UDP. +This also implies that TCP segmentation offloading and large receive offload +are disabled. The default value is 0. .It Va hw.vtnet.fixup_needs_csum .It Va hw.vtnet. Ns Ar X Ns Va .fixup_needs_csum -This tunable enforces the calculation of a valid checksum for NEEDS_CSUM -packets. +This tunable enforces the calculation of a valid TCP or UDP checksum for +packets received with +.Dv VIRTIO_NET_HDR_F_NEEDS_CSUM +being set in the +.Va flags +field of the structure +.Vt struct virtio_net_hdr . +It also marks the checksum as being correct in the mbuf packet header. The default value is 0. +This tunable is deprecated and will be removed in +.Fx 16 . .It Va hw.vtnet.tso_disable .It Va hw.vtnet. Ns Ar X Ns Va .tso_disable -This tunable disables TSO. +This tunable disables TCP segmentation offloading. The default value is 0. .It Va hw.vtnet.lro_disable .It Va hw.vtnet. Ns Ar X Ns Va .lro_disable -This tunable disables LRO. -The default value is 0. +This tunable disables hardware TCP LRO. +The default value is 1. .It Va hw.vtnet.mq_disable .It Va hw.vtnet. Ns Ar X Ns Va .mq_disable This tunable disables multiqueue. @@ -106,17 +131,147 @@ This tunable sets the number of RX segments processed in one pass. The default value is 1024. .It Va hw.vtnet.lro_entry_count .It Va hw.vtnet. Ns Ar X Ns Va .lro_entry_count -This tunable sets the software LRO entry count. +This tunable sets the software TCP LRO entry count. The default value is 128, the minimum value is 8. .It Va hw.vtnet.lro_mbufq_depth .It Va hw.vtnet. Ns Ar X Ns Va .lro_mbufq_depth -This tunable sets the depth of the software LRO mbuf queue. +This tunable sets the depth of the software TCP LRO mbuf queue. The default value is 0. .It Va hw.vtnet.altq_disable This tunable disables ALTQ support, allowing the use of multiqueue instead. This option applies to all interfaces. The default value is 0. .El +.Sh TRANSMIT QUEUE STATISTICS +For each transmit queue of each interface the following read-only statistics +are provided: +.Bl -tag -width "xxxxxx" +.It Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .rescheduled +The number of times the transmit interrupt handler was rescheduled. +.It Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .tso +The number of times TCP segment offloading was performed. +.It Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .csum +The number of times transmit checksum offloading for UDP or TCP was +performed. +.It Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .omcasts +The number of multicast packets that were transmitted. +.It Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .obytes +The number of bytes that were transmitted (based on Ethernet frames). +.It Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .opackets +The number of packets that were transmitted (Ethernet frames). +.El +.Sh RECEIVE QUEUE STATISTICS +For each receive queue of each interface the following read-only statistics +are provided: +.Bl -tag -width "xxxxxx" +.It Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .rescheduled +The number of times the receive interrupt handler was rescheduled. +.It Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .host_lro +The number of times TCP large receive offload was performed. +.It Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .csum_failed +The number of times a packet with a request for receive or transmit checksum +offloading was received and this request failed. +The different reasons for the failure are counted by +.Va dev.vtnet. Ns Ar X Ns Va .rx_csum_inaccessible_ipproto , +.Va dev.vtnet. Ns Ar X Ns Va .rx_csum_bad_ipproto , +.Va dev.vtnet. Ns Ar X Ns Va .rx_csum_bad_ethtype , +and +.Va dev.vtnet. Ns Ar X Ns Va .rx_csum_bad_offset . +.It Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .csum +The number of times receive checksum offloading for UDP or TCP was performed. +.It Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .ierrors +The number of times an error occurred during input processing. +.It Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .iqdrops +The number of times a packet was dropped during input processing. +.It Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .ibytes +The number of bytes that were received (based on Ethernet frames). +.It Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .ipackets +The number of packets that were received (Ethernet frames). +.El +.Sh INTERFACE TRANSMIT STATISTICS +For each interface the following read-only transmit statistics are provided: +.Bl -tag -width "xxxxxx" +.It Va dev.vtnet. Ns Ar X Ns Va .tx_task_rescheduled +The sum of +.Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .rescheduled +over all transmit queues of the interface. +.It Va dev.vtnet. Ns Ar X Ns Va .tx_tso_offloaded +The sum of +.Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .tso +over all transmit queues of the interface. +.It Va dev.vtnet. Ns Ar X Ns Va .tx_csum_offloaded +The sum of +.Va dev.vtnet. Ns Ar X Ns Va .txq Ns Ar Y Ns Va .csum +over all transmit queues of the interface. +.It Va dev.vtnet. Ns Ar X Ns Va .tx_defrag_failed +The number of times an attempt to defragment an mbuf chain failed during a +transmit operation. +.It Va dev.vtnet. Ns Ar X Ns Va .tx_defragged +The number of times an mbuf chain was defragmented during a transmit operation. +.It Va dev.vtnet. Ns Ar X Ns Va .tx_tso_without_csum +The number of times TCP segment offloading was attempted without transmit +checksum offloading. +.It Va dev.vtnet. Ns Ar X Ns Va .tx_tso_not_tcp +The number of times TCP segment offloading was attempted for a non-TCP packet. +.It Va dev.vtnet. Ns Ar X Ns Va .tx_csum_proto_mismatch +The number of times the IP protocol version of the transmit checksum +offloading request did not match the IP protocol version of the packet. +.It Va dev.vtnet. Ns Ar X Ns Va .tx_csum_unknown_ethtype +The number of times a transmit offload operation was requested for an +ethernet frame for which the EtherType was neither IPv4 nor IPv6 +(considering simple VLAN tagging). +.El +.Sh INTERFACE RECEIVE STATISTICS +For each interface the following read-only receive statistics are provided: +.Bl -tag -width "xxxxxx" +.It Va dev.vtnet. Ns Ar X Ns Va .rx_task_rescheduled +The sum of +.Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .rescheduled +over all receive queues of the interface. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_csum_offloaded +The sum of +.Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .csum +over all receive queues of the interface. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_csum_failed +The sum of +.Va dev.vtnet. Ns Ar X Ns Va .rxq Ns Ar Y Ns Va .csum_failed +over all receive queues of the interface. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_csum_inaccessible_ipproto +The number of times a packet with a request for receive or transmit checksum +offloading was received where the IP protocol was not accessible. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_csum_bad_offset +The number of times fixing the checksum required by +.Va hw.vtnet.fixup_needs_csum +or +.Va hw.vtnet. Ns Ar X Ns Va .fixup_needs_csum +was attempted for a packet where the csum is not located in the first mbuf. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_csum_bad_ipproto +The number of times a packet with a request for receive or transmit checksum +offloading was received where the IP protocol was neither TCP nor UDP. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_csum_bad_ethtype +The number of times a packet with a request for receive or transmit checksum +offloading was received where the EtherType was neither IPv4 nor IPv6. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_mergeable_failed +The number of times receiving a mergable buffer failed. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_enq_replacement_failed +The number of times the enqueuing the replacement receive mbuf chain failed. +.It Va dev.vtnet. Ns Ar X Ns Va .rx_frame_too_large +The number of times the frame was loger than the mbuf chain during large +receive offload without mergeable buffers. +.It Va dev.vtnet. Ns Ar X Ns Va .mbuf_alloc_failed +The number of times an mbuf cluster allocation for the receive buffer failed. +.El +.Sh INTERFACE CONFIGURATION PARAMETER +For each interface the following read-only configuration parameters are +provided: +.Bl -tag -width "xxxxxx" +.It Va dev.vtnet. Ns Ar X Ns Va .act_vq_pairs +The number of active virtqueue pairs. +.It Va dev.vtnet. Ns Ar X Ns Va .req_vq_pairs +The number of requested virtqueue pairs. +.It Va dev.vtnet. Ns Ar X Ns Va .max_vq_pairs +The maximum number of supported virtqueue pairs. +.El .Sh SEE ALSO .Xr arp 4 , .Xr netintro 4 , |