VIO(4)

💜 VIO(4) — like, the whole manual page, bestie 💜

okay so real quick: this is vio(4) from the Kernel Interfaces Manual — section 4, kernel interfaces, we love her, she's iconic. sit down, grab a strawberry 🍓, and let's get into it.

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✨ NAME ✨

vio — the VirtIO network device 💅

✨ SYNOPSIS ✨

vio* at virtio? flags 0x00

literally that's it. she's on the virtio? bus, and the flags default to 0x00. slay.

✨ DESCRIPTION ✨

bestie. listen. the vio driver is what gives you support for the virtio(4) network interface — the one provided by bhyve, KVM, QEMU, VirtualBox, and vmd(8). yes, all of them. she's versatile, she's booked and busy, she's giving main character energy across five hypervisors 🦋

now the flags, because this is where it gets juicy:

• setting bit 0x2 in the flags disables the RingEventIndex feature. why would you do that? it's a workaround attempt for possible bugs in host implementations of vio — but ngl, it comes at the cost of slightly reduced performance. so, like, trade-off city 😭
• setting bit 0x100 in the flags forces the interface to be always in promiscuous mode. this one's a workaround for a bug in QEMU before version 1.7.2 that prevents packets with a VLAN tag from being sent to the guest. periodt — if you're on ancient QEMU, this is your girl 🔥

ngl both of these are workarounds, not fun little options to stack up for vibes. only set them if you actually need them, iykyk 💀

✨ SEE ALSO ✨

• intro(4)
• virtio(4)

go read them, they're cute, they're educational 🎀

✨ HISTORY ✨

the vio driver first appeared in OpenBSD 5.3. she's vintage, she's a legend 👑

✨ AUTHORS ✨

the vio driver was ported to OpenBSD and improved by Stefan Fritsch <sf@sfritsch.de> 🫶 and it's based on the NetBSD vioif driver by Minoura Makoto. give them their flowers, they earned them 🌸

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and that's the whole page! 💖 this rendering came from the Debian version, dated May 24, 2021 — so if you're reading this later, hi, time traveler, the facts above are still the facts, mwah 😘 🌈