STRUCT SVSM_VTPM_CMD_RESPONSE(9)

💅 NAME 💅

okay so bestie, welcome to the manual page for struct svsm_vtpm_cmd_response — it's the struct you get back for a TPM_SEND_COMMAND response. that's it, that's the vibe. it's the lil' container that holds whatever the TPM sent back to you 🫶

(this whole page lives under struct svsm...cmd_response(9) in the Kernel API Manual, iykyk ✨)

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🦋 SYNOPSIS 🦋

struct svsm_vtpm_cmd_response {
    u32 buf_size;
    u8 buf[];
 };

like, literally two members. tiny struct, main character energy 👑

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🎀 Members 🎀

• buf_size — the size of the output buffer that follows. it's the u32 that tells you how much buffer is actually behind the curtain 🍓
• buf — a buffer of size buf_size. the actual payload lives here, and its size is, surprise, buf_size 💀

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🌸 Description 🌸

so this struct is defined by the AMD SVSM spec [1] — specifically in the section called "8.2 SVSM_VTPM_CMD Call", Table 17: TPM_SEND_COMMAND Response Structure. and here's how that table lays out, no cap:

• Byte Offset 0x000 — Size (Bytes) 4 — Meaning: response size (in bytes) ✨
• Byte Offset 0x004 — Size (Bytes) Variable — Meaning: response 💖

so yeah, the first 4 bytes tell you how big the response is, and then the response itself is variable-length right after. it's giving "header then payload", and honestly? obsessed 🌈

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💜 SEE ALSO 💜

• Kernel file ./include/linux/tpm_svsm.h
• struct svsm_vtpm_request(9)
• struct svsm_vtpm_response(9)
• struct svsm_vtpm_cmd_request(9)
• svsm_vtpm_cmd_request_fill(9)
• svsm_vtpm_cmd_response_parse(9)

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anyway bestie that's the whole page, mwah 💋 — this one's from ./include/linux, dated October 2026, and it signs off as struct svsm...cmd_response(9). slay, go read those TPM structs, periodt 🔥👑