How network VF works with hn(4) on Hyper-V in transparent mode:
- Each network VF has a cooresponding hn(4).
- The network VF and the it's cooresponding hn(4) have the same hardware
address.
- Once the network VF is attached, the cooresponding hn(4) waits several
seconds to make sure that the network VF attach routing completes, then:
o Set the intersection of the network VF's if_capabilities and the
cooresponding hn(4)'s if_capabilities to the cooresponding hn(4)'s
if_capabilities. And adjust the cooresponding hn(4) if_capable and
if_hwassist accordingly. (*)
o Make sure that the cooresponding hn(4)'s TSO parameters meet the
constraints posed by both the network VF and the cooresponding hn(4).
(*)
o The network VF's if_input is overridden. The overriding if_input
changes the input packet's rcvif to the cooreponding hn(4). The
network layers are tricked into thinking that all packets are
neceived by the cooresponding hn(4).
o If the cooresponding hn(4) was brought up, bring up the network VF.
The transmission dispatched to the cooresponding hn(4) are
redispatched to the network VF.
o Bringing down the cooresponding hn(4) also brings down the network
VF.
o All IOCTLs issued to the cooresponding hn(4) are pass-through'ed to
the network VF; the cooresponding hn(4) changes its internal state
if necessary.
o The media status of the cooresponding hn(4) solely relies on the
network VF.
o If there are multicast filters on the cooresponding hn(4), allmulti
will be enabled on the network VF. (**)
- Once the network VF is detached. Undo all damages did to the
cooresponding hn(4) in the above item.
NOTE:
No operation should be issued directly to the network VF, if the
network VF transparent mode is enabled. The network VF transparent mode
can be enabled by setting tunable hw.hn.vf_transparent to 1. The network
VF transparent mode is _not_ enabled by default, as of this commit.
The benefit of the network VF transparent mode is that the network VF
attachment and detachment are transparent to all network layers; e.g. live
migration detaches and reattaches the network VF.
The major drawbacks of the network VF transparent mode:
- The netmap(4) support is lost, even if the VF supports it.
- ALTQ does not work, since if_start method cannot be properly supported.
(*)
These decisions were made so that things will not be messed up too much
during the transition period.
(**)
This does _not_ need to go through the fancy multicast filter management
stuffs like what vlan(4) has, at least currently:
- As of this write, multicast does not work in Azure.
- As of this write, multicast packets go through the cooresponding hn(4).
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D11803
This prepares for the upcoming transparent VF support.
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D11708
This status will be reported if the backend NIC is wireless; it's not
useful. Due to the high frequency of the reporting, this could be
pretty annoying; ignore it.
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D11651
The VF-HN map will be used later on to implement "transparent VF".
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D11618
Hyper-V hot channel effect:
Operation latency on hot channel is only _half_ of the operation
latency on cold channels.
This commit takes the advantage of the above Hyper-V host channel
effect, and can reduce more than 75% latency and more than 50%
latency stdev, i.e. lower and more stable/predictable latency,
for various types of web server workloads.
MFC after: 3 days
Sponsored by: Microsoft
Under certain conditions on certain versions of Hyper-V, the RNDIS
rxfilter is _not_ zero on the hypervisor side after the successful
RNDIS initialization, which breaks the assumption of any following
code (well, it breaks the RNDIS API contract actually). Clear the
RNDIS rxfilter explicitly, drain packets sneaking through, and drain
the interrupt taskqueues scheduled due to the stealth packets.
Reported by: dexuan@
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D10230
This makes it easier for the userland script to find the releated
VF interface.
Reviewed by: sephe
Approved by: sephe (mentor)
MFC after: 2 weeks
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D9101
Hyper-V's NIC SR-IOV implementation needs a Hyper-V synthetic NIC and
a VF NIC to work together (both NICs have the same MAC address), mainly to
support seamless live migration.
When the VF device becomes UP (or DOWN), the synthetic NIC driver needs
to switch the data path from the synthetic NIC to the VF (or the opposite).
Note: multicast/broadcast packets are still received through the synthetic
NIC and we need to inject the packets through the VF interface (if the VF is
UP), even if the synthetic NIC is DOWN (so we need to force the rxfilter
to be NDIS_PACKET_TYPE_PROMISCUOUS, when the VF is UP).
Reviewed by: sephe
Approved by: sephe (mentor)
MFC after: 2 weeks
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8964
It's unnecessary because the upper nework stack does the same checking.
In the case of Hyper-V SR-IOV, we need to remove the checking because
1) multicast/broadcast packets are still received through the synthetic
NIC and we need to inject the packets through the VF interface;
2) we must inject the packets even if the synthetic NIC is down, or has
a different MTU from the VF device.
Reviewed by: sephe
Approved by: sephe (mentor)
MFC after: 2 weeks
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8962
This will be used by the coming NIC SR-IOV patch.
Reviewed by: sephe
Approved by: sephe (mentor)
MFC after: 2 weeks
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8909
If bufring is used for per-TX ring descs, don't update "available"
counter, which is only used to help debugging.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8674
It was an experimental tunable, and is now deemed to be road blocker
for further changes. Time to retire it.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8654
Just in case that no chimney sending buffer can be used.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8619
Since hypervisor will not drain the TX bufring, once the channels are
revoked:
- Setup vmbus orphan handler properly.
- Make sure that suspension will not wait the TX bufring draining
forever.
- GC the pending TX descs on detach path, before freeing the busdma
stuffs.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8559
Just in case, the # of TX/RX rings is changed upon synthetic parts
re-attach.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8520
And re-enable SIOCADDMULTI/SIOCDELMULTI, after WITNESS warning is fixed.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8489
Currently, it is only applied to packet sent through chimney sending
buffers. Not enabled by default yet.
This one gives 20%~30% performance boost for non-TSO usage in both
bit/packet rate tests and nginx performance test.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8560
And put them under HN_IFSTART_SUPPORT, which is by default on until
we whack the if_start related bits from base system.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8392
- Move the SYSINIT to DRIVER/SECOND, i.e. after the vm_guest becomes
determistic.
- Minor style changes.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8370
Mainly because the host side only set TCPCS and IPCS even for
UDP datagrams.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8369
And use large default temporary channel packer buffer; we really
don't want it to be expanded at run time.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8367
