virtsnd_pcm_msg_complete(9)

💖 virtsnd_pcm_msg_complete(9) 💖

okay bestie, welcome to the Kernel API Manual page for virtsnd_pcm_msg_complete(9). This one is short, lowkey iconic, and very “know what it does and move on,” so let’s get into it. 🫶✨

✨ NAME ✨

• virtsnd_pcm_msg_complete — Complete an I/O message. That’s the whole assignment, and it ate. 💅

🌸 SYNOPSIS 🌸

void virtsnd_pcm_msg_complete (struct virtio_pcm_msg *msg , size_t
       written_bytes );

🎀 ARGUMENTS 🎀

• msg — the I/O message. like, the message in question, bestie. 💌
• written_bytes — the number of bytes written to the message. no cap. 🔢

🌈 DESCRIPTION 🌈

okay so completion of the message means the elapsed period. That’s the literal vibe. If transmission is allowed, then each completed message is immediately placed back at the end of the queue. Immediately. Back of the queue. not me being obsessed with queue behavior, but here we are. 🔥

For the playback substream, written_bytes is equal to sizeof(msg->status). periodt. 🎧

For the capture substream, written_bytes is equal to sizeof(msg->status) plus the number of captured bytes. That’s the math, and it’s giving exact. 🧮✨

🚨 CONTEXT 🚨

🚨 Interrupt context alert 🚨 — this runs in interrupt context. It takes and releases the VirtIO substream spinlock. So like, respect the context, bestie. 💅

🔗 SEE ALSO 🔗

okay bestie, go read these too — they’re all part of the same little kernel friend group:

• Kernel file ./sound/virtio/virtio_pcm_msg.c
• struct virtio_pcm_msg(9)
• enum pcm_msg_sg_index(9)
• virtsnd_pcm_sg_num(9)
• virtsnd_pcm_sg_from(9)
• virtsnd_pcm_msg_alloc(9)
• virtsnd_pcm_msg_free(9)
• virtsnd_pcm_msg_send(9)
• virtsnd_pcm_msg_pending_num(9)
• virtsnd_pcm_notify_cb(9)
• virtsnd_pcm_tx_notify_cb(9)
• virtsnd_pcm_rx_notify_cb(9)
• virtsnd_pcm_ctl_msg_alloc(9)

mwah 💋 — source/version: ./sound/virtio, date: October 2026, page: virtsnd_pcm_msg_complete(9). byeee 🫶✨