PowerVM provides an isolated Platform Keystore(PKS) storage allocation
for each LPAR with individually managed access controls to store
sensitive information securely. It provides a new set of hypervisor
calls for Linux kernel to access PKS storage.

Define PLPKS driver using H_CALL interface to access PKS storage.

Signed-off-by: Nayna Jain <na...@linux.ibm.com>
---
 arch/powerpc/include/asm/hvcall.h             |  12 +-
 arch/powerpc/include/asm/plpks.h              |  92 ++++
 arch/powerpc/platforms/pseries/Kconfig        |  10 +
 arch/powerpc/platforms/pseries/Makefile       |   2 +
 arch/powerpc/platforms/pseries/plpks/Makefile |   7 +
 arch/powerpc/platforms/pseries/plpks/plpks.c  | 517 ++++++++++++++++++
 6 files changed, 639 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/include/asm/plpks.h
 create mode 100644 arch/powerpc/platforms/pseries/plpks/Makefile
 create mode 100644 arch/powerpc/platforms/pseries/plpks/plpks.c

diff --git a/arch/powerpc/include/asm/hvcall.h 
b/arch/powerpc/include/asm/hvcall.h
index d92a20a85395..1da429235632 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -97,6 +97,7 @@
 #define H_OP_MODE      -73
 #define H_COP_HW       -74
 #define H_STATE                -75
+#define H_IN_USE       -77
 #define H_UNSUPPORTED_FLAG_START       -256
 #define H_UNSUPPORTED_FLAG_END         -511
 #define H_MULTI_THREADS_ACTIVE -9005
@@ -321,10 +322,19 @@
 #define H_SCM_UNBIND_ALL        0x3FC
 #define H_SCM_HEALTH            0x400
 #define H_SCM_PERFORMANCE_STATS 0x418
+#define H_PKS_GET_CONFIG       0x41C
+#define H_PKS_SET_PASSWORD     0x420
+#define H_PKS_GEN_PASSWORD     0x424
+#define H_PKS_WRITE_OBJECT     0x42C
+#define H_PKS_GEN_KEY          0x430
+#define H_PKS_READ_OBJECT      0x434
+#define H_PKS_REMOVE_OBJECT    0x438
+#define H_PKS_CONFIRM_OBJECT_FLUSHED   0x43C
 #define H_RPT_INVALIDATE       0x448
 #define H_SCM_FLUSH            0x44C
 #define H_GET_ENERGY_SCALE_INFO        0x450
-#define MAX_HCALL_OPCODE       H_GET_ENERGY_SCALE_INFO
+#define H_PKS_SIGNED_UPDATE    0x454
+#define MAX_HCALL_OPCODE       H_PKS_SIGNED_UPDATE
 
 /* Scope args for H_SCM_UNBIND_ALL */
 #define H_UNBIND_SCOPE_ALL (0x1)
diff --git a/arch/powerpc/include/asm/plpks.h b/arch/powerpc/include/asm/plpks.h
new file mode 100644
index 000000000000..c3b544bdbcb6
--- /dev/null
+++ b/arch/powerpc/include/asm/plpks.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2022 IBM Corporation
+ * Author: Nayna Jain <na...@linux.ibm.com>
+ *
+ * Platform keystore for pseries LPAR(PLPKS).
+ */
+
+#ifndef _PSERIES_PLPKS_H
+#define _PSERIES_PLPKS_H
+
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+
+#define OSSECBOOTAUDIT 0x40000000
+#define OSSECBOOTENFORCE 0x20000000
+#define WORLDREADABLE 0x08000000
+#define SIGNEDUPDATE 0x01000000
+
+struct plpks_var {
+       char *component;
+       u8 *name;
+       u16 namelen;
+       u32 policy;
+       u16 datalen;
+       u8 *data;
+};
+
+struct plpks_var_name {
+       u16 namelen;
+       u8  *name;
+};
+
+struct plpks_var_name_list {
+       u32 varcount;
+       struct plpks_var_name varlist[];
+};
+
+struct plpks_config {
+       u8 version;
+       u8 flags;
+       u32 rsvd0;
+       u16 maxpwsize;
+       u16 maxobjlabelsize;
+       u16 maxobjsize;
+       u32 totalsize;
+       u32 usedspace;
+       u32 supportedpolicies;
+       u64 rsvd1;
+} __packed;
+
+/**
+ * Successful return from this API  implies PKS is available.
+ * This is used to initialize kernel driver and user interfaces.
+ */
+extern struct plpks_config *plpks_get_config(void);
+
+/**
+ * Updates the authenticated variable. It expects NULL as the component.
+ */
+extern int plpks_signed_update_var(struct plpks_var var);
+
+/**
+ * Writes the specified var and its data to PKS.
+ * Any caller of PKS driver should present a valid component type for
+ * their variable.
+ */
+extern int plpks_write_var(struct plpks_var var);
+
+/**
+ * Removes the specified var and its data from PKS.
+ */
+extern int plpks_remove_var(char *component, struct plpks_var_name vname);
+
+/**
+ * Returns the data for the specified os variable.
+ */
+extern int plpks_read_os_var(struct plpks_var *var);
+
+/**
+ * Returns the data for the specified firmware variable.
+ */
+extern int plpks_read_fw_var(struct plpks_var *var);
+
+/**
+ * Returns the data for the specified bootloader variable.
+ */
+extern int plpks_read_bootloader_var(struct plpks_var *var);
+
+#endif
diff --git a/arch/powerpc/platforms/pseries/Kconfig 
b/arch/powerpc/platforms/pseries/Kconfig
index f7fd91d153a4..6c1ca487103f 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -142,6 +142,16 @@ config IBMEBUS
        help
          Bus device driver for GX bus based adapters.
 
+config PSERIES_PLPKS
+       depends on PPC_PSERIES
+       tristate "Support for the Platform Key Storage"
+       help
+         PowerVM provides an isolated Platform Keystore(PKS) storage
+         allocation for each LPAR with individually managed access
+         controls to store sensitive information securely. Select this
+         config to enable operating system interface to hypervisor to
+         access this space.
+
 config PAPR_SCM
        depends on PPC_PSERIES && MEMORY_HOTPLUG && LIBNVDIMM
        tristate "Support for the PAPR Storage Class Memory interface"
diff --git a/arch/powerpc/platforms/pseries/Makefile 
b/arch/powerpc/platforms/pseries/Makefile
index 7aaff5323544..d6a9209e08c0 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -37,3 +37,5 @@ obj-$(CONFIG_ARCH_HAS_CC_PLATFORM)    += cc_platform.o
 # nothing that operates in real mode is safe for KASAN
 KASAN_SANITIZE_ras.o := n
 KASAN_SANITIZE_kexec.o := n
+
+obj-$(CONFIG_PSERIES_PLPKS)      += plpks/
diff --git a/arch/powerpc/platforms/pseries/plpks/Makefile 
b/arch/powerpc/platforms/pseries/plpks/Makefile
new file mode 100644
index 000000000000..e651ace920db
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/plpks/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (C) 2022 IBM Corporation
+# Author: Nayna Jain <na...@linux.ibm.com>
+#
+
+obj-$(CONFIG_PSERIES_PLPKS)  += plpks.o
diff --git a/arch/powerpc/platforms/pseries/plpks/plpks.c 
b/arch/powerpc/platforms/pseries/plpks/plpks.c
new file mode 100644
index 000000000000..1edb5905bbef
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/plpks/plpks.c
@@ -0,0 +1,517 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * POWER LPAR Platform KeyStore (PLPKS)
+ * Copyright (C) 2022 IBM Corporation
+ * Author: Nayna Jain <na...@linux.ibm.com>
+ *
+ * Provides access to variables stored in Power LPAR Platform KeyStore(PLPKS).
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <asm/hvcall.h>
+#include <asm/plpks.h>
+#include <asm/unaligned.h>
+#include <asm/machdep.h>
+
+#define MODULE_VERS "1.0"
+#define MODULE_NAME "pseries-plpks"
+
+#define PKS_FW_OWNER   0x1
+#define PKS_BOOTLOADER_OWNER   0x2
+#define PKS_OS_OWNER   0x3
+
+#define PKS_VAR_LINUX  0x01
+#define PKS_VAR_COMMON 0x04
+
+#define MAX_LABEL_ATTR_SIZE 16
+#define MAX_NAME_SIZE 240
+#define MAX_DATA_SIZE 4000
+
+static bool configset;
+static struct plpks_config *config;
+static u8 *ospassword;
+static u16 ospasswordlength;
+
+struct plpks_auth {
+       u8 version;
+       u8 consumer;
+       __be64 rsvd0;
+       __be32 rsvd1;
+       __be16 passwordlength;
+       u8 password[];
+} __attribute__ ((packed, aligned(16)));
+
+struct label_attr {
+       u8 prefix[8];
+       u8 version;
+       u8 os;
+       u8 length;
+       u8 reserved[5];
+};
+
+struct label {
+       struct label_attr attr;
+       u8 name[MAX_NAME_SIZE];
+};
+
+static int pseries_status_to_err(int rc)
+{
+       int err;
+
+       switch (rc) {
+       case H_SUCCESS:
+               err = 0;
+               break;
+       case H_FUNCTION:
+               err = -ENXIO;
+               break;
+       case H_P2:
+       case H_P3:
+       case H_P4:
+       case H_P5:
+       case H_P6:
+               err = -EINVAL;
+               break;
+       case H_NOT_FOUND:
+               err = -ENOENT;
+               break;
+       case H_BUSY:
+               err = -EBUSY;
+               break;
+       case H_AUTHORITY:
+               err = -EPERM;
+               break;
+       case H_NO_MEM:
+               err = -ENOMEM;
+               break;
+       case H_RESOURCE:
+               err = -EEXIST;
+               break;
+       case H_TOO_BIG:
+               err = -EFBIG;
+               break;
+       default:
+               err = -EINVAL;
+       }
+
+       return err;
+}
+
+static int plpks_gen_password(void)
+{
+       unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = {0};
+       u8 consumer = PKS_OS_OWNER;
+       int rc;
+
+       ospassword = kzalloc(config->maxpwsize, GFP_KERNEL);
+       if (!ospassword)
+               return -ENOMEM;
+
+       ospasswordlength = config->maxpwsize;
+       rc = plpar_hcall(H_PKS_GEN_PASSWORD,
+                       retbuf,
+                       consumer,
+                       0,
+                       virt_to_phys(ospassword),
+                       config->maxpwsize);
+
+       return pseries_status_to_err(rc);
+}
+
+static int construct_auth(u8 consumer, struct plpks_auth **auth)
+{
+       pr_debug("max password size is %u\n", config->maxpwsize);
+
+       if (!auth || (consumer > 3))
+               return -EINVAL;
+
+       *auth = kmalloc(struct_size(*auth, password, config->maxpwsize),
+                       GFP_KERNEL);
+       if (!*auth)
+               return -ENOMEM;
+
+       (*auth)->version = 1;
+       (*auth)->consumer = consumer;
+       (*auth)->rsvd0 = 0;
+       (*auth)->rsvd1 = 0;
+       if ((consumer == PKS_FW_OWNER) || (consumer == PKS_BOOTLOADER_OWNER)) {
+               pr_debug("consumer is bootloader or firmware\n");
+               (*auth)->passwordlength = 0;
+               return 0;
+       }
+
+       (*auth)->passwordlength = ospasswordlength;
+
+       memcpy((*auth)->password, ospassword, flex_array_size(*auth, password,
+                                             (*auth)->passwordlength));
+       (*auth)->passwordlength = cpu_to_be16((*auth)->passwordlength);
+
+       return 0;
+}
+
+/**
+ * Label is combination of label attributes + name.
+ * Label attributes are used internally by kernel and not exposed to the user.
+ */
+static int construct_label(char *component, u8 *name, u16 namelen, u8 **label)
+{
+       int varlen;
+       int len = 0;
+       int llen = 0;
+       u8 anyos;
+       int i;
+       int rc = 0;
+       u8 labellength = MAX_LABEL_ATTR_SIZE;
+
+       if (!label)
+               return -EINVAL;
+
+       varlen = namelen + sizeof(struct label_attr);
+       *label = kzalloc(varlen, GFP_KERNEL);
+
+       if (!*label)
+               return -ENOMEM;
+
+       if (component) {
+               len = strlen(component);
+               memcpy(*label, component, len);
+       }
+       llen = len;
+
+       if (component)
+               len = 8 - strlen(component);
+       else
+               len = 8;
+
+       memset(*label + llen, 0, len);
+       llen = llen + len;
+
+       ((*label)[llen]) = 0;
+       llen = llen + 1;
+
+       if (component)
+               if (memcmp(component, "sed-opal", 8) == 0)
+                       anyos = PKS_VAR_COMMON;
+               else
+                       anyos = PKS_VAR_LINUX;
+       else
+               anyos = PKS_VAR_LINUX;
+       memcpy(*label + llen, &anyos, 1);
+       llen = llen + 1;
+
+       memcpy(*label + llen, &labellength, 1);
+       llen = llen + 1;
+
+       memset(*label + llen, 0, 5);
+       llen = llen + 5;
+
+       memcpy(*label + llen, name, namelen);
+       llen = llen + namelen;
+
+       for (i = 0; i < llen; i++)
+               pr_debug("%c", (*label)[i]);
+
+       rc = llen;
+       return rc;
+}
+
+static int _plpks_get_config(void)
+{
+       unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = {0};
+       int rc;
+       size_t size = sizeof(struct plpks_config);
+
+       config = kzalloc(size, GFP_KERNEL);
+       if (!config)
+               return -ENOMEM;
+
+       rc = plpar_hcall(H_PKS_GET_CONFIG,
+                       retbuf,
+                       virt_to_phys(config),
+                       size);
+
+       if (rc != H_SUCCESS)
+               return pseries_status_to_err(rc);
+
+       config->rsvd0 = be32_to_cpu(config->rsvd0);
+       config->maxpwsize = be16_to_cpu(config->maxpwsize);
+       config->maxobjlabelsize = be16_to_cpu(config->maxobjlabelsize);
+       config->maxobjsize = be16_to_cpu(config->maxobjsize);
+       config->totalsize = be32_to_cpu(config->totalsize);
+       config->usedspace = be32_to_cpu(config->usedspace);
+       config->supportedpolicies = be32_to_cpu(config->supportedpolicies);
+       config->rsvd1 = be64_to_cpu(config->rsvd1);
+
+       configset = true;
+
+       return 0;
+}
+
+int plpks_signed_update_var(struct plpks_var var)
+{
+       unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = {0};
+       int rc;
+       u8 *label;
+       u16 varlen;
+       u8 *data;
+       struct plpks_auth *auth;
+       u64 flags;
+       u64 continuetoken;
+
+       if (!var.data || (var.datalen <= 0)
+                 || (var.namelen > MAX_NAME_SIZE)
+                 || (var.datalen > MAX_DATA_SIZE))
+               return -EINVAL;
+
+       if (!(var.policy & SIGNEDUPDATE))
+               return -EINVAL;
+
+       rc = construct_auth(PKS_OS_OWNER, &auth);
+       if (rc)
+               return rc;
+
+       rc = construct_label(var.component, var.name, var.namelen, &label);
+       if (rc <= 0)
+               goto out;
+
+       varlen =  rc;
+       pr_debug("Name to be written is %s of label size %d\n", label, varlen);
+
+       memcpy(&flags, var.data, sizeof(u64));
+       data = kzalloc(var.datalen - sizeof(u64), GFP_KERNEL);
+       memcpy(data, var.data + sizeof(u64), var.datalen - sizeof(u64));
+
+       do {
+               rc = plpar_hcall(H_PKS_SIGNED_UPDATE,
+                               retbuf,
+                               virt_to_phys(auth),
+                               virt_to_phys(label),
+                               varlen,
+                               var.policy,
+                               flags,
+                               virt_to_phys(data),
+                               var.datalen);
+
+               continuetoken = retbuf[0];
+
+       } while (rc == H_BUSY);
+
+       rc = pseries_status_to_err(rc);
+
+       kfree(label);
+       kfree(data);
+
+out:
+       kfree(auth);
+
+       return rc;
+}
+EXPORT_SYMBOL(plpks_signed_update_var);
+
+int plpks_write_var(struct plpks_var var)
+{
+       unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = {0};
+       int rc;
+       u8 *label;
+       u16 varlen;
+       u8 *data = var.data;
+       struct plpks_auth *auth;
+
+       if (!var.component || !data || (var.datalen <= 0)
+                          || (var.namelen > MAX_NAME_SIZE)
+                          || (var.datalen > MAX_DATA_SIZE))
+               return -EINVAL;
+
+       if (var.policy & SIGNEDUPDATE)
+               return -EINVAL;
+
+       rc = construct_auth(PKS_OS_OWNER, &auth);
+       if (rc)
+               return rc;
+
+       rc = construct_label(var.component, var.name, var.namelen, &label);
+       if (rc <= 0)
+               goto out;
+
+       varlen =  rc;
+       pr_debug("Name to be written is %s of label size %d\n", label, varlen);
+       rc = plpar_hcall(H_PKS_WRITE_OBJECT,
+                       retbuf,
+                       virt_to_phys(auth),
+                       virt_to_phys(label),
+                       varlen,
+                       var.policy,
+                       virt_to_phys(data),
+                       var.datalen);
+
+       rc = pseries_status_to_err(rc);
+       kfree(label);
+
+out:
+       kfree(auth);
+
+       return rc;
+}
+EXPORT_SYMBOL(plpks_write_var);
+
+int plpks_remove_var(char *component, struct plpks_var_name vname)
+{
+       unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = {0};
+       int rc;
+       u8 *label;
+       u16 varlen;
+       struct plpks_auth *auth;
+
+       if (!component || vname.namelen > MAX_NAME_SIZE)
+               return -EINVAL;
+
+       rc = construct_auth(PKS_OS_OWNER, &auth);
+       if (rc)
+               return rc;
+
+       rc = construct_label(component, vname.name, vname.namelen, &label);
+       if (rc <= 0)
+               goto out;
+
+       varlen = rc;
+       pr_debug("Name to be written is %s of label size %d\n", label, varlen);
+       rc = plpar_hcall(H_PKS_REMOVE_OBJECT,
+                       retbuf,
+                       virt_to_phys(auth),
+                       virt_to_phys(label),
+                       varlen);
+
+       rc = pseries_status_to_err(rc);
+       kfree(label);
+
+out:
+       kfree(auth);
+
+       return rc;
+}
+EXPORT_SYMBOL(plpks_remove_var);
+
+static int plpks_read_var(u8 consumer, struct plpks_var *var)
+{
+       unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = {0};
+       int rc;
+       u16 outlen = config->maxobjsize;
+       u8 *label;
+       u8 *out;
+       u16 varlen;
+       struct plpks_auth *auth;
+
+       if (var->namelen > MAX_NAME_SIZE)
+               return -EINVAL;
+
+       rc = construct_auth(PKS_OS_OWNER, &auth);
+       if (rc)
+               return rc;
+
+       rc = construct_label(var->component, var->name, var->namelen, &label);
+       if (rc <= 0)
+               goto out;
+
+       varlen = rc;
+       pr_debug("Name to be written is %s of label size %d\n", label, varlen);
+       out = kzalloc(outlen, GFP_KERNEL);
+       if (!out)
+               goto out1;
+
+       rc = plpar_hcall(H_PKS_READ_OBJECT,
+                       retbuf,
+                       virt_to_phys(auth),
+                       virt_to_phys(label),
+                       varlen,
+                       virt_to_phys(out),
+                       outlen);
+
+       if (rc != H_SUCCESS) {
+               pr_err("Failed to read %d\n", rc);
+               rc = pseries_status_to_err(rc);
+               goto out2;
+       }
+
+       if ((var->datalen == 0) || (var->datalen > retbuf[0]))
+               var->datalen = retbuf[0];
+
+       var->data = kzalloc(var->datalen, GFP_KERNEL);
+       if (!var->data) {
+               rc = -ENOMEM;
+               goto out2;
+       }
+       var->policy = retbuf[1];
+
+       memcpy(var->data, out, var->datalen);
+
+out2:
+       kfree(out);
+
+out1:
+       kfree(label);
+
+out:
+       kfree(auth);
+
+       return rc;
+}
+
+int plpks_read_os_var(struct plpks_var *var)
+{
+       return plpks_read_var(PKS_OS_OWNER, var);
+}
+EXPORT_SYMBOL(plpks_read_os_var);
+
+int plpks_read_fw_var(struct plpks_var *var)
+{
+       return plpks_read_var(PKS_FW_OWNER, var);
+}
+EXPORT_SYMBOL(plpks_read_fw_var);
+
+int plpks_read_bootloader_var(struct plpks_var *var)
+{
+       return plpks_read_var(PKS_BOOTLOADER_OWNER, var);
+}
+EXPORT_SYMBOL(plpks_read_bootloader_var);
+
+struct plpks_config *plpks_get_config(void)
+{
+
+       if (!configset) {
+               if (_plpks_get_config())
+                       return NULL;
+       }
+
+       return config;
+}
+EXPORT_SYMBOL(plpks_get_config);
+
+int __init pseries_plpks_init(void)
+{
+       int rc = 0;
+
+       rc = _plpks_get_config();
+
+       if (rc) {
+               pr_err("Error initializing plpks\n");
+               return rc;
+       }
+
+       rc = plpks_gen_password();
+       if (rc) {
+               if (rc == H_IN_USE) {
+                       rc = 0;
+               } else {
+                       pr_err("Failed setting password %d\n", rc);
+                       rc = pseries_status_to_err(rc);
+                       return rc;
+               }
+       }
+
+       return rc;
+}
+arch_initcall(pseries_plpks_init);
-- 
2.27.0

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