[Skiboot] [PATCH v2 15/20] hdata/spira: add ibm, secureboot node in P9

[Claudio Carvalho]

In P9, skiboot builds the device tree from the HDAT. These are the
"ibm,secureboot" node changes compared to P8:

- The Container-Verification-Code (CVC), a.k.a. ROM code, is no longer
  stored in a secure ROM with static address. In P9, it is stored in a
  hostboot reserved memory and each service provided also has a version,
  not only an offset.

- The hash-algo property is not provided via HDAT, instead it provides
  the hw-key-hash-size, which is indeed the information required by the
  CVC to verify containers.

This parses the iplparams_sysparams HDAT structure and creates the
"ibm,secureboot", which is bumped to "ibm,secureboot-v2".

In "ibm,secureboot-v2":
- hash-algo property is superseded by hw-key-hash-size.
- container verification code is explicitly described by a child node.
  Added in a subsequent patch.

Signed-off-by: Claudio Carvalho <cclaudio at linux.vnet.ibm.com>
Reviewed-by: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall at gmail.com>
---
 hdata/spira.c | 39 +++++++++++++++++++++++++++++++++++++++
 hdata/spira.h | 15 +++++++++------
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/hdata/spira.c b/hdata/spira.c
index 936fadc..f3976bd 100644
--- a/hdata/spira.c
+++ b/hdata/spira.c
@@ -933,6 +933,42 @@ static void add_nmmu(void)
 	}
 }
 
+static void dt_init_secureboot_node(const struct iplparams_sysparams *sysparams)
+{
+	struct dt_node *node;
+	u16 sys_sec_setting;
+	u16 hw_key_hash_size;
+
+	node = dt_new(dt_root, "ibm,secureboot");
+	assert(node);
+
+	dt_add_property_string(node, "compatible", "ibm,secureboot-v2");
+
+	sys_sec_setting = be16_to_cpu(sysparams->sys_sec_setting);
+	if (sys_sec_setting & SEC_CONTAINER_SIG_CHECKING)
+		dt_add_property(node, "secure-enabled", NULL, 0);
+	if (sys_sec_setting & SEC_HASHES_EXTENDED_TO_TPM)
+		dt_add_property(node, "trusted-enabled", NULL, 0);
+
+	hw_key_hash_size = be16_to_cpu(sysparams->hw_key_hash_size);
+
+	/* Prevent hw-key-hash buffer overflow by truncating hw-key-hash-size if
+	 * it is bigger than the hw-key-hash buffer.
+	 * Secure boot will be enforced later in skiboot, if the hw-key-hash-size
+	 * was not supposed to be SYSPARAMS_HW_KEY_HASH_MAX.
+	 */
+	if (hw_key_hash_size > SYSPARAMS_HW_KEY_HASH_MAX) {
+		prlog(PR_ERR, "IPLPARAMS: hw-key-hash-size=%d too big, "
+		      "truncating to %d\n", hw_key_hash_size,
+		      SYSPARAMS_HW_KEY_HASH_MAX);
+		hw_key_hash_size = SYSPARAMS_HW_KEY_HASH_MAX;
+	}
+
+	dt_add_property(node, "hw-key-hash", sysparams->hw_key_hash,
+			hw_key_hash_size);
+	dt_add_property_cells(node, "hw-key-hash-size", hw_key_hash_size);
+}
+
 static void add_iplparams_sys_params(const void *iplp, struct dt_node *node)
 {
 	const struct iplparams_sysparams *p;
@@ -1019,6 +1055,9 @@ static void add_iplparams_sys_params(const void *iplp, struct dt_node *node)
 	sys_attributes = be32_to_cpu(p->sys_attributes);
 	if (sys_attributes & SYS_ATTR_RISK_LEVEL)
 		dt_add_property(node, "elevated-risk-level", NULL, 0);
+
+	if (version >= 0x60 && proc_gen >= proc_gen_p9)
+		dt_init_secureboot_node(p);
 }
 
 static void add_iplparams_ipl_params(const void *iplp, struct dt_node *node)
diff --git a/hdata/spira.h b/hdata/spira.h
index 190afad..17c6a2a 100644
--- a/hdata/spira.h
+++ b/hdata/spira.h
@@ -355,6 +355,7 @@ struct iplparams_sysparams {
 	__be32		abc_bus_speed;
 	__be32		wxyz_bus_speed;
 	__be32		sys_eco_mode;
+#define SYS_ATTR_MULTIPLE_TPM PPC_BIT32(0)
 #define SYS_ATTR_RISK_LEVEL PPC_BIT32(3)
 	__be32		sys_attributes;
 	__be32		mem_scrubbing;
@@ -369,12 +370,14 @@ struct iplparams_sysparams {
 	uint8_t		split_core_mode;	/* >= 0x5c */
 	uint8_t		reserved[3];
 	uint8_t		sys_vendor[64];		/* >= 0x5f */
-	/* >= 0x60 */
-	__be16		sys_sec_setting;
-	__be16		tpm_config_bit;
-	__be16		tpm_drawer;
-	__be16		reserved2;
-	uint8_t		hw_key_hash[64];
+#define SEC_CONTAINER_SIG_CHECKING PPC_BIT16(0)
+#define SEC_HASHES_EXTENDED_TO_TPM PPC_BIT16(1)
+	__be16		sys_sec_setting;	/* >= 0x60 */
+	__be16		tpm_config_bit;		/* >= 0x60 */
+	__be16		tpm_drawer;		/* >= 0x60 */
+	__be16		hw_key_hash_size;	/* >= 0x60 */
+#define SYSPARAMS_HW_KEY_HASH_MAX   64
+	uint8_t		hw_key_hash[SYSPARAMS_HW_KEY_HASH_MAX];  /* >= 0x60 */
 	uint8_t		sys_family_str[64];	/* vendor,name */
 	uint8_t		sys_type_str[64];	/* vendor,type */
 } __packed;
-- 
2.7.4