MFC r313911:

Spell VMXNET3_LEGACY_TX correctly.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Improve transmit sending offload, TSO, algorithm in general.

The current TSO limitation feature only takes the total number of
bytes in an mbuf chain into account and does not limit by the number
of mbufs in a chain. Some kinds of hardware is limited by two
factors. One is the fragment length and the second is the fragment
count. Both of these limits need to be taken into account when doing
TSO. Else some kinds of hardware might have to drop completely valid
mbuf chains because they cannot loaded into the given hardware's DMA
engine. The new way of doing TSO limitation has been made backwards
compatible as input from other FreeBSD developers and will use
defaults for values not set.

Reviewed by: adrian, rmacklem
Sponsored by: Mellanox Technologies
MFC after: 1 week

Revert r271504. A new patch to solve this issue will be made.

Suggested by: adrian @

Improve transmit sending offload, TSO, algorithm in general.

The current TSO limitation feature only takes the total number of
bytes in an mbuf chain into account and does not limit by the number
of mbufs in a chain. Some kinds of hardware is limited by two
factors. One is the fragment length and the second is the fragment
count. Both of these limits need to be taken into account when doing
TSO. Else some kinds of hardware might have to drop completely valid
mbuf chains because they cannot loaded into the given hardware's DMA
engine. The new way of doing TSO limitation has been made backwards
compatible as input from other FreeBSD developers and will use
defaults for values not set.

MFC after: 1 week
Sponsored by: Mellanox Technologies

Handle multiple calls to rxq_eof for single packet completion

This requires the VMware vmxnet3 device to flip the start of packet
descriptor's generation before the rest of the packet's descriptors
have been loaded into the Rx ring. I've never observed this behavior,
and it seems to make the most sense not to do it this way. But it is
not a lot of work for the driver to handle this situation just in case.

MFC after: 1 week

Add Tx/Rx multiqueue support to vmx(4)

As a prerequisite for multiple queues, the guest must have MSIX enabled.
Unfortunately, to work around device passthrough bugs, FreeBSD disables
MSIX when running as a VMWare guest due to the hw.pci.honor_msi_blacklist
tunable; this tunable must be disabled for multiple queues.

Also included is various minor changes from the projects/vmxnet branch.

MFC after: 1 month

Do not provide a hint of the guest's OS version

The calculation can overflow if __FreeBSD_version is big
enough, and it does not appear to be required.

Reported by: grehan
Approved by: re (gjb)

Use correct type for the vmx vlan filter table

Approved by: re (glebius, gjb)

Few more minor if_vmx tweaks

- Allow the Rx/Tx queue sizes to be configured by tunables
- Bail out earlier if the Tx queue unlikely has enough free
descriptors to hold the frame
- Cleanup some of the offloading capabilities handling

Couple minor if_vmx tweaks

- Use queue size fields from the Tx/Rx queues in various places
instead of (currently the same values) from the softc.
- Fix potential crash in detach if the attached failed to alloc
queue memory.
- Move the VMXNET3_MAX_RX_SEGS define to a better spot.
- Tweak frame size calculation w.r.t. ETHER_ALIGN. This could be
tweaked some more, or removed since it probably doesn't matter
much for x86 (and the x86 class of machines this driver will
be used on).

Add vmx(4), a VMware VMXNET3 ethernet driver ported from OpenBSD