On 6/4/24 23:35, Jan Klemkow wrote:
> Hi,

Hi Jan,

> In general hardware devices handle VLAN Tags and checksum/segmentation
> offloading together with VLAN offloading.  But, some devices like
> vio(4), do no provide the capability of assisted VLAN tag injection.
> 
> The following diff introduces a new IFCAP flag.  So, vlan(4) injects an
> inline VLAN Tag, but also inherit the offloading capabilities of this
> parent device.

on latest Proxmox with ixl(4) for the HV and vlan(4) on vio(4) within
the VMs i see the following changes:

- with this diff 'tcpbench' increases from around 1.7Gbps to 3.0Gbps avg

- with this diff + 'vio(4): TCP Large Receive Offload' on tech@ [1] it
   goes up to 9.4Gbps with an average of around 8.0Gbps

Aside from benchmarks, real world transfers stay more or less the same.
Around 0.7Gbits with encryption, 1.1Gbits w/o.


[1] https://marc.info/?l=openbsd-tech&m=171690506012984&w=2

Thanks for the work,

	-Mark


> bye,
> Jan
> 
> Index: sbin/ifconfig/ifconfig.8
> ===================================================================
> RCS file: /cvs/src/sbin/ifconfig/ifconfig.8,v
> diff -u -p -r1.399 ifconfig.8
> --- sbin/ifconfig/ifconfig.8	11 Jan 2024 17:22:04 -0000	1.399
> +++ sbin/ifconfig/ifconfig.8	4 Jun 2024 21:22:11 -0000
> @@ -294,6 +294,9 @@ tag.
>   On transmit, the device can add the
>   .Xr vlan 4
>   tag.
> +.It Sy VLAN_HWOFFLOAD
> +On transmit, the device can handle checksum or TSO offload without
> +.Sy VLAN_HWTAGGING .
>   .It Sy WOL
>   The device supports Wake on LAN (WoL).
>   .It Sy hardmtu
> Index: sbin/ifconfig/ifconfig.c
> ===================================================================
> RCS file: /cvs/src/sbin/ifconfig/ifconfig.c,v
> diff -u -p -r1.472 ifconfig.c
> --- sbin/ifconfig/ifconfig.c	18 May 2024 02:44:22 -0000	1.472
> +++ sbin/ifconfig/ifconfig.c	4 Jun 2024 21:22:11 -0000
> @@ -125,7 +125,7 @@
>   
>   #define HWFEATURESBITS							\
>   	"\024\1CSUM_IPv4\2CSUM_TCPv4\3CSUM_UDPv4"			\
> -	"\5VLAN_MTU\6VLAN_HWTAGGING\10CSUM_TCPv6"			\
> +	"\5VLAN_MTU\6VLAN_HWTAGGING\7VLAN_HWOFFLOAD\10CSUM_TCPv6"	\
>   	"\11CSUM_UDPv6\15TSOv4\16TSOv6\17LRO\20WOL"
>   
>   struct ifencap {
> Index: sys/dev/pv/if_vio.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pv/if_vio.c,v
> diff -u -p -r1.37 if_vio.c
> --- sys/dev/pv/if_vio.c	4 Jun 2024 09:51:52 -0000	1.37
> +++ sys/dev/pv/if_vio.c	4 Jun 2024 21:22:11 -0000
> @@ -605,6 +605,7 @@ vio_attach(struct device *parent, struct
>   	ifp->if_start = vio_start;
>   	ifp->if_ioctl = vio_ioctl;
>   	ifp->if_capabilities = IFCAP_VLAN_MTU;
> +	ifp->if_capabilities = IFCAP_VLAN_HWOFFLOAD;
>   	if (virtio_has_feature(vsc, VIRTIO_NET_F_CSUM))
>   		ifp->if_capabilities |= IFCAP_CSUM_TCPv4|IFCAP_CSUM_UDPv4|
>   		    IFCAP_CSUM_TCPv6|IFCAP_CSUM_UDPv6;
> Index: sys/net/if.h
> ===================================================================
> RCS file: /cvs/src/sys/net/if.h,v
> diff -u -p -r1.216 if.h
> --- sys/net/if.h	11 Apr 2024 15:08:18 -0000	1.216
> +++ sys/net/if.h	4 Jun 2024 21:22:11 -0000
> @@ -249,6 +249,7 @@ struct if_status_description {
>   #define	IFCAP_CSUM_UDPv4	0x00000004	/* can do IPv4/UDP csum */
>   #define	IFCAP_VLAN_MTU		0x00000010	/* VLAN-compatible MTU */
>   #define	IFCAP_VLAN_HWTAGGING	0x00000020	/* hardware VLAN tag support */
> +#define	IFCAP_VLAN_HWOFFLOAD	0x00000040	/* hw offload w/ inline tag */
>   #define	IFCAP_CSUM_TCPv6	0x00000080	/* can do IPv6/TCP checksums */
>   #define	IFCAP_CSUM_UDPv6	0x00000100	/* can do IPv6/UDP checksums */
>   #define	IFCAP_TSOv4		0x00001000	/* IPv4/TCP segment offload */
> Index: sys/net/if_vlan.c
> ===================================================================
> RCS file: /cvs/src/sys/net/if_vlan.c,v
> diff -u -p -r1.218 if_vlan.c
> --- sys/net/if_vlan.c	23 Dec 2023 10:52:54 -0000	1.218
> +++ sys/net/if_vlan.c	4 Jun 2024 21:22:11 -0000
> @@ -523,7 +523,7 @@ vlan_up(struct vlan_softc *sc)
>   	/*
>   	 * Note: In cases like vio(4) and em(4) where the offsets of the
>   	 * csum can be freely defined, we could actually do csum offload
> -	 * for VLAN and QINQ packets.
> +	 * for QINQ packets.
>   	 */
>   	if (sc->sc_type != ETHERTYPE_VLAN) {
>   		/*
> @@ -531,10 +531,14 @@ vlan_up(struct vlan_softc *sc)
>   		 * ethernet type (0x8100).
>   		 */
>   		ifp->if_capabilities = 0;
> -	} else if (ISSET(ifp0->if_capabilities, IFCAP_VLAN_HWTAGGING)) {
> +	} else if (ISSET(ifp0->if_capabilities, IFCAP_VLAN_HWTAGGING) ||
> +	    ISSET(ifp0->if_capabilities, IFCAP_VLAN_HWOFFLOAD)) {
>   		/*
>   		 * Chips that can do hardware-assisted VLAN encapsulation, can
>   		 * calculate the correct checksum for VLAN tagged packets.
> +		 *
> +		 * Hardware which does checksum offloading, but not VLAN tag
> +		 * injection, have to set IFCAP_VLAN_HWOFFLOAD.
>   		 */
>   		ifp->if_capabilities = ifp0->if_capabilities &
>   		    (IFCAP_CSUM_MASK | IFCAP_TSOv4 | IFCAP_TSOv6);
> 
-- 
Mark Patruck ( mark at wrapped.cx )
GPG key 0xF2865E51 / 187F F6D3 EE04 1DCE 1C74  F644 0D3C F66F F286 5E51

https://www.wrapped.cx