x86/sev: Extend the config-fs attestation support for an SVSM

When an SVSM is present, the guest can also request attestation reports
from it. These SVSM attestation reports can be used to attest the SVSM
and any services running within the SVSM.

Extend the config-fs attestation support to provide such. This involves
creating four new config-fs attributes:

  - 'service-provider' (input)
    This attribute is used to determine whether the attestation request
    should be sent to the specified service provider or to the SEV
    firmware. The SVSM service provider is represented by the value
    'svsm'.

  - 'service_guid' (input)
    Used for requesting the attestation of a single service within the
    service provider. A null GUID implies that the SVSM_ATTEST_SERVICES
    call should be used to request the attestation report. A non-null
    GUID implies that the SVSM_ATTEST_SINGLE_SERVICE call should be used.

  - 'service_manifest_version' (input)
    Used with the SVSM_ATTEST_SINGLE_SERVICE call, the service version
    represents a specific service manifest version be used for the
    attestation report.

  - 'manifestblob' (output)
    Used to return the service manifest associated with the attestation
    report.

Only display these new attributes when running under an SVSM.

  [ bp: Massage.
   - s/svsm_attestation_call/svsm_attest_call/g ]

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/965015dce3c76bb8724839d50c5dea4e4b5d598f.1717600736.git.thomas.lendacky@amd.com

1 files changed, 30 insertions, 1 deletions

diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 9c6f269d4bf5..ac5886ce252e 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -214,6 +214,27 @@ struct svsm_pvalidate_call {
 					 sizeof(struct svsm_pvalidate_entry))
 
 /*
+ * The SVSM Attestation related structures
+ */
+struct svsm_loc_entry {
+	u64 pa;
+	u32 len;
+	u8 rsvd[4];
+};
+
+struct svsm_attest_call {
+	struct svsm_loc_entry report_buf;
+	struct svsm_loc_entry nonce;
+	struct svsm_loc_entry manifest_buf;
+	struct svsm_loc_entry certificates_buf;
+
+	/* For attesting a single service */
+	u8 service_guid[16];
+	u32 service_manifest_ver;
+	u8 rsvd[4];
+};
+
+/*
  * SVSM protocol structure
  */
 struct svsm_call {
@@ -236,6 +257,10 @@ struct svsm_call {
 #define SVSM_CORE_CREATE_VCPU		2
 #define SVSM_CORE_DELETE_VCPU		3
 
+#define SVSM_ATTEST_CALL(x)		((1ULL << 32) | (x))
+#define SVSM_ATTEST_SERVICES		0
+#define SVSM_ATTEST_SINGLE_SERVICE	1
+
 #ifdef CONFIG_AMD_MEM_ENCRYPT
 
 extern u8 snp_vmpl;
@@ -317,6 +342,7 @@ bool snp_init(struct boot_params *bp);
 void __noreturn snp_abort(void);
 void snp_dmi_setup(void);
 int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
+int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call, struct svsm_attest_call *input);
 void snp_accept_memory(phys_addr_t start, phys_addr_t end);
 u64 snp_get_unsupported_features(u64 status);
 u64 sev_get_status(void);
@@ -349,7 +375,10 @@ static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *in
 {
 	return -ENOTTY;
 }
-
+static inline int snp_issue_svsm_attest_req(u64 call_id, struct svsm_call *call, struct svsm_attest_call *input)
+{
+	return -ENOTTY;
+}
 static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
 static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
 static inline u64 sev_get_status(void) { return 0; }