linux/drivers/virt/coco/sevguest/sevguest.h
Brijesh Singh fce96cf044 virt: Add SEV-SNP guest driver
The SEV-SNP specification provides the guest a mechanism to communicate
with the PSP without risk from a malicious hypervisor who wishes to
read, alter, drop or replay the messages sent. The driver uses
snp_issue_guest_request() to issue GHCB SNP_GUEST_REQUEST or
SNP_EXT_GUEST_REQUEST NAE events to submit the request to PSP.

The PSP requires that all communication should be encrypted using key
specified through a struct snp_guest_platform_data descriptor.

Userspace can use SNP_GET_REPORT ioctl() to query the guest attestation
report.

See SEV-SNP spec section Guest Messages for more details.

  [ bp: Remove the "what" from the commit message, massage. ]

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-44-brijesh.singh@amd.com
2022-04-07 16:47:12 +02:00

99 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2021 Advanced Micro Devices, Inc.
*
* Author: Brijesh Singh <brijesh.singh@amd.com>
*
* SEV-SNP API spec is available at https://developer.amd.com/sev
*/
#ifndef __VIRT_SEVGUEST_H__
#define __VIRT_SEVGUEST_H__
#include <linux/types.h>
#define MAX_AUTHTAG_LEN 32
/* See SNP spec SNP_GUEST_REQUEST section for the structure */
enum msg_type {
SNP_MSG_TYPE_INVALID = 0,
SNP_MSG_CPUID_REQ,
SNP_MSG_CPUID_RSP,
SNP_MSG_KEY_REQ,
SNP_MSG_KEY_RSP,
SNP_MSG_REPORT_REQ,
SNP_MSG_REPORT_RSP,
SNP_MSG_EXPORT_REQ,
SNP_MSG_EXPORT_RSP,
SNP_MSG_IMPORT_REQ,
SNP_MSG_IMPORT_RSP,
SNP_MSG_ABSORB_REQ,
SNP_MSG_ABSORB_RSP,
SNP_MSG_VMRK_REQ,
SNP_MSG_VMRK_RSP,
SNP_MSG_TYPE_MAX
};
enum aead_algo {
SNP_AEAD_INVALID,
SNP_AEAD_AES_256_GCM,
};
struct snp_guest_msg_hdr {
u8 authtag[MAX_AUTHTAG_LEN];
u64 msg_seqno;
u8 rsvd1[8];
u8 algo;
u8 hdr_version;
u16 hdr_sz;
u8 msg_type;
u8 msg_version;
u16 msg_sz;
u32 rsvd2;
u8 msg_vmpck;
u8 rsvd3[35];
} __packed;
struct snp_guest_msg {
struct snp_guest_msg_hdr hdr;
u8 payload[4000];
} __packed;
/*
* The secrets page contains 96-bytes of reserved field that can be used by
* the guest OS. The guest OS uses the area to save the message sequence
* number for each VMPCK.
*
* See the GHCB spec section Secret page layout for the format for this area.
*/
struct secrets_os_area {
u32 msg_seqno_0;
u32 msg_seqno_1;
u32 msg_seqno_2;
u32 msg_seqno_3;
u64 ap_jump_table_pa;
u8 rsvd[40];
u8 guest_usage[32];
} __packed;
#define VMPCK_KEY_LEN 32
/* See the SNP spec version 0.9 for secrets page format */
struct snp_secrets_page_layout {
u32 version;
u32 imien : 1,
rsvd1 : 31;
u32 fms;
u32 rsvd2;
u8 gosvw[16];
u8 vmpck0[VMPCK_KEY_LEN];
u8 vmpck1[VMPCK_KEY_LEN];
u8 vmpck2[VMPCK_KEY_LEN];
u8 vmpck3[VMPCK_KEY_LEN];
struct secrets_os_area os_area;
u8 rsvd3[3840];
} __packed;
#endif /* __VIRT_SEVGUEST_H__ */