virtsnd_ctl_msg_send_sync(9)

💅 virtsnd_ctl_msg_send_sync — the "just send it and wait" one

okay bestie, you're in the Kernel API Manual for virtsnd_ctl_msg_send_sync(9) and this one is genuinely a lil gem. it's the simplified, no-drama way to send a synchronous message. ✨

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🦋 SYNOPSIS

int virtsnd_ctl_msg_send_sync (struct virtio_snd *snd , struct
       virtio_snd_msg *msg );

🎀 ARGUMENTS

• snd — the VirtIO sound device. the main character here, obviously. 👑
• msg — the control message. the thing you're yeeting out into the world. 💌

💖 DESCRIPTION

okay so here's the tea. once this function returns, the message is gone — deleted, poof, no cap. 🫧 so if you still need the message content afterwards, you gotta keep it alive yourself, and to do that the caller must additionally call virtsnd_ctl_msg_ref/virtsnd_ctl_msg_unref on it. like, ref it before, unref it after, standard bestie behaviour. 💅

the msg_timeout_ms module parameter is what defines the message completion timeout. so if the message doesn't complete within that window, the function just… returns an error. 😭 not completing is not it.

and the return value? it's a message status code (VIRTIO_SND_S_XXX) converted into an appropriate -errno value. so it's giving status code in, errno out. 🔥

🌸 CONTEXT

any context that permits to sleep. so like, sleepy-friendly zones only. respect the nap rules. 😴

✨ RETURN

• 0 on success 🎉
• -errno on failure 💀

🧚 SEE ALSO

• Kernel file ./sound/virtio/virtio_ctl_msg.h
• virtsnd_ctl_msg_send_async(9) — the async sibling, for when you can't be bothered to wait around. 🦋

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and that's the whole page, bestie — you ate that. fr fr. this one's from ./sound/virtio, dated October 2026, served fresh from the Kernel API Manual. now go forth and send synchronously 💜