[viona, mac-filter, mcast] install guest multicast MAC filter tables via V7 ioctls - #1210
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zeeshanlakhani wants to merge 3 commits into
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[viona, mac-filter, mcast] install guest multicast MAC filter tables via V7 ioctls#1210zeeshanlakhani wants to merge 3 commits into
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This work fixes a [known issue](#1053) where legacy interface writes could arrive after feature negotiation ended or a `DRIVER_OK` flag was set, causing side-effects and unwanted reconfiguration. We fix this with a guard before `set_features` that checks that negotiation has closed first, setting `NEEDS_RESET` (discarding the write) if a different mask is requested. A write that produces the same mask is just a no-op here. For modern, common interfaces, writes after `FEATURES_OK` could mutate the state's `negotiated_features` without calling `set_features` itself, causing the mask to diverge from what the device had already applied. This came up in iximeow's [comment](#1053 (comment)), which proposed `NEEDS_RESET` for feature writes between `FEATURES_OK` and `DRIVER_OK`. To handle this, we apply a similar methodology, but for `CommonConfigReg::DriverFeature` once negotiation is closed. We also reject retried `FEATURES_OK` flag sets while `NEEDS_RESET` status is already set. We need these changes for upcoming viona work involving setting MAC filters.
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…via V7 ioctls Guest multicast interest has been driven by `VIONA_PROMISC_MULTI`, delivering multicast frames for the guests to filter. We saw duplication issues at guest Rx when packets reached both the classified and promiscuous callbacks. This led to the viona interface V7 scoped changes in [illumos-gate](https://github.com/oxidecomputer/illumos-gate/blob/5ffff4b86e486e1f9d7860be1368386699a7829a) / [change 775](https://code.oxide.computer/c/illumos-gate/+/775). Given the upstream changes, this work introduces `VNA_IOC_SET_MAC_FILTERS` to install guest multicast tables on the underlay MAC client backing viona. `VNA_IOC_GET_MAC_FILTERS` is used for reading back installed entries from the table. Classified delivery can replace all-multicast mode once the guest supplies a table that fits and no broader receive mode is necessary. All-multicast remains the fallback for guests that haven't sent a table request or have exceeded the kernel's capacity. Most of the work here goes into handling ioctl failures, semantic result codes, and fallback. This includes explicit multicast table management, reset handling, and Falcon-build `AllVlan` logic. Most importantly (most scary), this raises the minimum required host viona API to V7. We're keeping the V1 viona state payload for now, with import / export handling for the multicast table state. This is the first of a few different PRs upcoming, including - [ ] CTRL_RX receive-mode handling - [ ] send notification on `NEEDS_RESET` status
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zeeshanlakhani
removed this pull request from stack #1211
September 9, 2026 00:12
zeeshanlakhani
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September 9, 2026 00:20
- merge in #1212 when accepted.
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Guest multicast interest has been driven by
VIONA_PROMISC_MULTI, delivering multicast frames for the guests to filter. We saw duplication issues at guest Rx when packets reached both the classified and promiscuous callbacks. This led to the viona interface V7 scoped changes in illumos-gate / change 775.Given the upstream changes, this work introduces
VNA_IOC_SET_MAC_FILTERSto install guest multicast tables on the underlay MAC client backing viona.VNA_IOC_GET_MAC_FILTERSis used for reading back installed entries from the table. Classified delivery can replace all-multicast mode once the guest supplies a table that fits and no broader receive mode is necessary. All-multicast remains the fallback for guests that haven't sent a table request or have exceeded the kernel's capacity.Most of the work here goes into handling ioctl failures, semantic result codes, and fallback. This includes explicit multicast table management, reset handling, and Falcon-build
AllVlanlogic.Most importantly (most scary), this raises the minimum required host viona API to V7. We're keeping the V1 viona state payload for now, with import / export handling for the multicast table state.
Note: This work will fail on CI as don't have special handling. Chat with @iximeow for more.
This is the first of a few different PRs upcoming, including
NEEDS_RESETstatus