[PATCH v3 1/4] powerpc/powernv: Add OPAL API interface to access secure variable

Nayna Jain
2019-08-26T13:24:06Z

The X.509 certificates trusted by the platform and required to secure boot
the OS kernel are wrapped in secure variables, which are controlled by
OPAL.

This patch adds firmware/kernel interface to read and write OPAL secure
variables based on the unique key.

This support can be enabled using CONFIG_OPAL_SECVAR.

Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
---
arch/powerpc/include/asm/opal-api.h | 5 +-
arch/powerpc/include/asm/opal.h | 7 +-
arch/powerpc/include/asm/powernv.h | 2 +
arch/powerpc/include/asm/secvar.h | 35 +++++
arch/powerpc/kernel/Makefile | 2 +-
arch/powerpc/kernel/secvar-ops.c | 19 +++
arch/powerpc/platforms/powernv/Kconfig | 6 +
arch/powerpc/platforms/powernv/Makefile | 1 +
arch/powerpc/platforms/powernv/opal-call.c | 3 +
arch/powerpc/platforms/powernv/opal-secvar.c | 138 +++++++++++++++++++
arch/powerpc/platforms/powernv/opal.c | 5 +
11 files changed, 220 insertions(+), 3 deletions(-)
create mode 100644 arch/powerpc/include/asm/secvar.h
create mode 100644 arch/powerpc/kernel/secvar-ops.c
create mode 100644 arch/powerpc/platforms/powernv/opal-secvar.c

diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 383242eb0dea..b238b4f26c5b 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -208,7 +208,10 @@
#define OPAL_HANDLE_HMI2 166
#define OPAL_NX_COPROC_INIT 167
#define OPAL_XIVE_GET_VP_STATE 170
-#define OPAL_LAST 170
+#define OPAL_SECVAR_GET 173
+#define OPAL_SECVAR_GET_NEXT 174
+#define OPAL_SECVAR_ENQUEUE_UPDATE 175
+#define OPAL_LAST 175

#define QUIESCE_HOLD 1 /* Spin all calls at entry */
#define QUIESCE_REJECT 2 /* Fail all calls with OPAL_BUSY */
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 57bd029c715e..0606b1d22db4 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -296,7 +296,11 @@ int opal_set_power_shift_ratio(u32 handle, int token, u32 psr);
int opal_sensor_group_clear(u32 group_hndl, int token);
int opal_sensor_group_enable(u32 group_hndl, int token, bool enable);
int opal_nx_coproc_init(uint32_t chip_id, uint32_t ct);
-
+int opal_secvar_get(const char *key, uint64_t key_len, u8 *data,
+ uint64_t *data_size);
+int opal_secvar_get_next(const char *key, uint64_t *key_len, uint64_t key_size);
+int opal_secvar_enqueue_update(const char *key, uint64_t key_len, u8 *data,
+ uint64_t data_size);
s64 opal_signal_system_reset(s32 cpu);
s64 opal_quiesce(u64 shutdown_type, s32 cpu);

@@ -387,6 +391,7 @@ void opal_wake_poller(void);
void opal_powercap_init(void);
void opal_psr_init(void);
void opal_sensor_groups_init(void);
+void opal_secvar_init(void);

#endif /* __ASSEMBLY__ */

diff --git a/arch/powerpc/include/asm/powernv.h b/arch/powerpc/include/asm/powernv.h
index e1a858718716..cff980a85dd2 100644
--- a/arch/powerpc/include/asm/powernv.h
+++ b/arch/powerpc/include/asm/powernv.h
@@ -12,10 +12,12 @@ extern void powernv_set_nmmu_ptcr(unsigned long ptcr);
void pnv_program_cpu_hotplug_lpcr(unsigned int cpu, u64 lpcr_val);

void pnv_tm_init(void);
+
#else
static inline void powernv_set_nmmu_ptcr(unsigned long ptcr) { }

static inline void pnv_tm_init(void) { }
+
#endif

#endif /* _ASM_POWERNV_H */
diff --git a/arch/powerpc/include/asm/secvar.h b/arch/powerpc/include/asm/secvar.h
new file mode 100644
index 000000000000..f27655cb5db8
--- /dev/null
+++ b/arch/powerpc/include/asm/secvar.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 IBM Corporation
+ * Author: Nayna Jain <nayna@linux.ibm.com>
+ *
+ * PowerPC secure variable operations.
+ */
+#ifndef SECVAR_OPS_H
+#define SECVAR_OPS_H
+
+#include <linux/types.h>
+#include <linux/errno.h>
+
+extern const struct secvar_operations *secvar_ops;
+
+struct secvar_operations {
+ int (*get)(const char *key, uint64_t key_len, u8 *data,
+ uint64_t *data_size);
+ int (*get_next)(const char *key, uint64_t *key_len,
+ uint64_t keysize);
+ int (*set)(const char *key, uint64_t key_len, u8 *data,
+ uint64_t data_size);
+};
+
+#ifdef CONFIG_PPC_SECURE_BOOT
+
+extern void set_secvar_ops(const struct secvar_operations *ops);
+
+#else
+
+static inline void set_secvar_ops(const struct secvar_operations *ops) { }
+
+#endif
+
+#endif
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 520b1c814197..9041563f1c74 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -157,7 +157,7 @@ endif
obj-$(CONFIG_EPAPR_PARAVIRT) += epapr_paravirt.o epapr_hcalls.o
obj-$(CONFIG_KVM_GUEST) += kvm.o kvm_emul.o

-obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o ima_arch.o
+obj-$(CONFIG_PPC_SECURE_BOOT) += secboot.o ima_arch.o secvar-ops.o

# Disable GCOV, KCOV & sanitizers in odd or sensitive code
GCOV_PROFILE_prom_init.o := n
diff --git a/arch/powerpc/kernel/secvar-ops.c b/arch/powerpc/kernel/secvar-ops.c
new file mode 100644
index 000000000000..e067bc0c2336
--- /dev/null
+++ b/arch/powerpc/kernel/secvar-ops.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 IBM Corporation
+ * Author: Nayna Jain <nayna@linux.ibm.com>
+ *
+ * This file initializes secvar operations for PowerPC Secureboot
+ */
+
+#include <stddef.h>
+#include <asm/secvar.h>
+
+const struct secvar_operations *secvar_ops;
+
+void set_secvar_ops(const struct secvar_operations *ops)
+{
+ if (!ops)
+ secvar_ops = NULL;
+ secvar_ops = ops;
+}
diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig
index 850eee860cf2..65b060539b5c 100644
--- a/arch/powerpc/platforms/powernv/Kconfig
+++ b/arch/powerpc/platforms/powernv/Kconfig
@@ -47,3 +47,9 @@ config PPC_VAS
VAS adapters are found in POWER9 based systems.

If unsure, say N.
+
+config OPAL_SECVAR
+ bool "OPAL Secure Variables"
+ depends on PPC_POWERNV
+ help
+ This enables the kernel to access OPAL secure variables.
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index da2e99efbd04..6651c742e530 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
obj-$(CONFIG_PPC_MEMTRACE) += memtrace.o
obj-$(CONFIG_PPC_VAS) += vas.o vas-window.o vas-debug.o
obj-$(CONFIG_OCXL_BASE) += ocxl.o
+obj-$(CONFIG_OPAL_SECVAR) += opal-secvar.o
diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c
index 29ca523c1c79..93106e867924 100644
--- a/arch/powerpc/platforms/powernv/opal-call.c
+++ b/arch/powerpc/platforms/powernv/opal-call.c
@@ -287,3 +287,6 @@ OPAL_CALL(opal_pci_set_pbcq_tunnel_bar, OPAL_PCI_SET_PBCQ_TUNNEL_BAR);
OPAL_CALL(opal_sensor_read_u64, OPAL_SENSOR_READ_U64);
OPAL_CALL(opal_sensor_group_enable, OPAL_SENSOR_GROUP_ENABLE);
OPAL_CALL(opal_nx_coproc_init, OPAL_NX_COPROC_INIT);
+OPAL_CALL(opal_secvar_get, OPAL_SECVAR_GET);
+OPAL_CALL(opal_secvar_get_next, OPAL_SECVAR_GET_NEXT);
+OPAL_CALL(opal_secvar_enqueue_update, OPAL_SECVAR_ENQUEUE_UPDATE);
diff --git a/arch/powerpc/platforms/powernv/opal-secvar.c b/arch/powerpc/platforms/powernv/opal-secvar.c
new file mode 100644
index 000000000000..6682013fb10b
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-secvar.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PowerNV code for secure variables
+ *
+ * Copyright (C) 2019 IBM Corporation
+ * Author: Claudio Carvalho <cclaudio@linux.ibm.com>
+ * Nayna Jain <nayna@linux.ibm.com>
+ *
+ * APIs to access secure variables managed by OPAL.
+ *
+ */
+
+#define pr_fmt(fmt) "secvar: "fmt
+
+#include <linux/types.h>
+#include <asm/opal.h>
+#include <asm/secvar.h>
+#include <asm/secboot.h>
+
+static int opal_status_to_err(int rc)
+{
+ int err;
+
+ switch (rc) {
+ case OPAL_SUCCESS:
+ err = 0;
+ break;
+ case OPAL_UNSUPPORTED:
+ err = -ENXIO;
+ break;
+ case OPAL_PARAMETER:
+ err = -EINVAL;
+ break;
+ case OPAL_RESOURCE:
+ err = -ENOSPC;
+ break;
+ case OPAL_HARDWARE:
+ err = -EIO;
+ break;
+ case OPAL_NO_MEM:
+ err = -ENOMEM;
+ break;
+ case OPAL_EMPTY:
+ err = -ENOENT;
+ break;
+ case OPAL_PARTIAL:
+ err = -EFBIG;
+ break;
+ default:
+ err = -EINVAL;
+ }
+
+ return err;
+}
+
+static bool is_opal_secvar_supported(void)
+{
+ static bool opal_secvar_supported;
+ static bool initialized;
+
+ if (initialized)
+ return opal_secvar_supported;
+
+ if (!is_powerpc_secvar_supported()) {
+ opal_secvar_supported = false;
+ goto out;
+ }
+
+ if (!opal_check_token(OPAL_SECVAR_GET)
+ || !opal_check_token(OPAL_SECVAR_GET_NEXT)
+ || !opal_check_token(OPAL_SECVAR_ENQUEUE_UPDATE)) {
+ pr_err("OPAL doesn't support secure variables\n");
+ opal_secvar_supported = false;
+ } else {
+ opal_secvar_supported = true;
+ }
+
+out:
+ initialized = true;
+
+ return opal_secvar_supported;
+}
+
+static int opal_get_variable(const char *key, uint64_t ksize,
+ u8 *data, uint64_t *dsize)
+{
+ int rc;
+
+ if (dsize)
+ *dsize = cpu_to_be64(*dsize);
+
+ rc = opal_secvar_get(key, ksize, data, dsize);
+
+ if (dsize)
+ *dsize = be64_to_cpu(*dsize);
+
+ return opal_status_to_err(rc);
+}
+
+static int opal_get_next_variable(const char *key, uint64_t *keylen,
+ uint64_t keysize)
+{
+ int rc;
+
+ if (keylen)
+ *keylen = cpu_to_be64(*keylen);
+
+ rc = opal_secvar_get_next(key, keylen, keysize);
+
+ if (keylen)
+ *keylen = be64_to_cpu(*keylen);
+
+ return opal_status_to_err(rc);
+}
+
+static int opal_set_variable(const char *key, uint64_t ksize, u8 *data,
+ uint64_t dsize)
+{
+ int rc;
+
+ rc = opal_secvar_enqueue_update(key, ksize, data, dsize);
+
+ return opal_status_to_err(rc);
+}
+
+static const struct secvar_operations opal_secvar_ops = {
+ .get = opal_get_variable,
+ .get_next = opal_get_next_variable,
+ .set = opal_set_variable,
+};
+
+void opal_secvar_init(void)
+{
+ if (!is_opal_secvar_supported())
+ set_secvar_ops(NULL);
+
+ set_secvar_ops(&opal_secvar_ops);
+}
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index aba443be7daa..3226961d451a 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -32,6 +32,8 @@
#include <asm/mce.h>
#include <asm/imc-pmu.h>
#include <asm/bug.h>
+#include <asm/secvar.h>
+#include <asm/secboot.h>

#include "powernv.h"

@@ -988,6 +990,9 @@ static int __init opal_init(void)
/* Initialise OPAL Power control interface */
opal_power_control_init();

+ /* Initialize OPAL secure variables */
+ opal_secvar_init();
+
return 0;
}
machine_subsys_initcall(powernv, opal_init);
--
2.20.1