blob: d95ec526587a950fcf773788d734c67bb149ff01 [file] [log] [blame]
/*
* AMD Platform Security Processor (PSP) interface
*
* Copyright (C) 2016-2017 Advanced Micro Devices, Inc.
*
* Author: Brijesh Singh <brijesh.singh@amd.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/spinlock_types.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/hw_random.h>
#include <linux/ccp.h>
#include "sp-dev.h"
#include "psp-dev.h"
#define DEVICE_NAME "sev"
static DEFINE_MUTEX(sev_cmd_mutex);
static struct sev_misc_dev *misc_dev;
static struct psp_device *psp_master;
static struct psp_device *psp_alloc_struct(struct sp_device *sp)
{
struct device *dev = sp->dev;
struct psp_device *psp;
psp = devm_kzalloc(dev, sizeof(*psp), GFP_KERNEL);
if (!psp)
return NULL;
psp->dev = dev;
psp->sp = sp;
snprintf(psp->name, sizeof(psp->name), "psp-%u", sp->ord);
return psp;
}
static irqreturn_t psp_irq_handler(int irq, void *data)
{
struct psp_device *psp = data;
unsigned int status;
int reg;
/* Read the interrupt status: */
status = ioread32(psp->io_regs + PSP_P2CMSG_INTSTS);
/* Check if it is command completion: */
if (!(status & BIT(PSP_CMD_COMPLETE_REG)))
goto done;
/* Check if it is SEV command completion: */
reg = ioread32(psp->io_regs + PSP_CMDRESP);
if (reg & PSP_CMDRESP_RESP) {
psp->sev_int_rcvd = 1;
wake_up(&psp->sev_int_queue);
}
done:
/* Clear the interrupt status by writing the same value we read. */
iowrite32(status, psp->io_regs + PSP_P2CMSG_INTSTS);
return IRQ_HANDLED;
}
static void sev_wait_cmd_ioc(struct psp_device *psp, unsigned int *reg)
{
psp->sev_int_rcvd = 0;
wait_event(psp->sev_int_queue, psp->sev_int_rcvd);
*reg = ioread32(psp->io_regs + PSP_CMDRESP);
}
static int sev_cmd_buffer_len(int cmd)
{
switch (cmd) {
case SEV_CMD_INIT: return sizeof(struct sev_data_init);
case SEV_CMD_PLATFORM_STATUS: return sizeof(struct sev_user_data_status);
case SEV_CMD_PEK_CSR: return sizeof(struct sev_data_pek_csr);
case SEV_CMD_PEK_CERT_IMPORT: return sizeof(struct sev_data_pek_cert_import);
case SEV_CMD_PDH_CERT_EXPORT: return sizeof(struct sev_data_pdh_cert_export);
case SEV_CMD_LAUNCH_START: return sizeof(struct sev_data_launch_start);
case SEV_CMD_LAUNCH_UPDATE_DATA: return sizeof(struct sev_data_launch_update_data);
case SEV_CMD_LAUNCH_UPDATE_VMSA: return sizeof(struct sev_data_launch_update_vmsa);
case SEV_CMD_LAUNCH_FINISH: return sizeof(struct sev_data_launch_finish);
case SEV_CMD_LAUNCH_MEASURE: return sizeof(struct sev_data_launch_measure);
case SEV_CMD_ACTIVATE: return sizeof(struct sev_data_activate);
case SEV_CMD_DEACTIVATE: return sizeof(struct sev_data_deactivate);
case SEV_CMD_DECOMMISSION: return sizeof(struct sev_data_decommission);
case SEV_CMD_GUEST_STATUS: return sizeof(struct sev_data_guest_status);
case SEV_CMD_DBG_DECRYPT: return sizeof(struct sev_data_dbg);
case SEV_CMD_DBG_ENCRYPT: return sizeof(struct sev_data_dbg);
case SEV_CMD_SEND_START: return sizeof(struct sev_data_send_start);
case SEV_CMD_SEND_UPDATE_DATA: return sizeof(struct sev_data_send_update_data);
case SEV_CMD_SEND_UPDATE_VMSA: return sizeof(struct sev_data_send_update_vmsa);
case SEV_CMD_SEND_FINISH: return sizeof(struct sev_data_send_finish);
case SEV_CMD_RECEIVE_START: return sizeof(struct sev_data_receive_start);
case SEV_CMD_RECEIVE_FINISH: return sizeof(struct sev_data_receive_finish);
case SEV_CMD_RECEIVE_UPDATE_DATA: return sizeof(struct sev_data_receive_update_data);
case SEV_CMD_RECEIVE_UPDATE_VMSA: return sizeof(struct sev_data_receive_update_vmsa);
case SEV_CMD_LAUNCH_UPDATE_SECRET: return sizeof(struct sev_data_launch_secret);
default: return 0;
}
return 0;
}
static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
{
struct psp_device *psp = psp_master;
unsigned int phys_lsb, phys_msb;
unsigned int reg, ret = 0;
if (!psp)
return -ENODEV;
/* Get the physical address of the command buffer */
phys_lsb = data ? lower_32_bits(__psp_pa(data)) : 0;
phys_msb = data ? upper_32_bits(__psp_pa(data)) : 0;
dev_dbg(psp->dev, "sev command id %#x buffer 0x%08x%08x\n",
cmd, phys_msb, phys_lsb);
print_hex_dump_debug("(in): ", DUMP_PREFIX_OFFSET, 16, 2, data,
sev_cmd_buffer_len(cmd), false);
iowrite32(phys_lsb, psp->io_regs + PSP_CMDBUFF_ADDR_LO);
iowrite32(phys_msb, psp->io_regs + PSP_CMDBUFF_ADDR_HI);
reg = cmd;
reg <<= PSP_CMDRESP_CMD_SHIFT;
reg |= PSP_CMDRESP_IOC;
iowrite32(reg, psp->io_regs + PSP_CMDRESP);
/* wait for command completion */
sev_wait_cmd_ioc(psp, &reg);
if (psp_ret)
*psp_ret = reg & PSP_CMDRESP_ERR_MASK;
if (reg & PSP_CMDRESP_ERR_MASK) {
dev_dbg(psp->dev, "sev command %#x failed (%#010x)\n",
cmd, reg & PSP_CMDRESP_ERR_MASK);
ret = -EIO;
}
print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data,
sev_cmd_buffer_len(cmd), false);
return ret;
}
static int sev_do_cmd(int cmd, void *data, int *psp_ret)
{
int rc;
mutex_lock(&sev_cmd_mutex);
rc = __sev_do_cmd_locked(cmd, data, psp_ret);
mutex_unlock(&sev_cmd_mutex);
return rc;
}
static int __sev_platform_init_locked(int *error)
{
struct psp_device *psp = psp_master;
int rc = 0;
if (!psp)
return -ENODEV;
if (psp->sev_state == SEV_STATE_INIT)
return 0;
rc = __sev_do_cmd_locked(SEV_CMD_INIT, &psp->init_cmd_buf, error);
if (rc)
return rc;
psp->sev_state = SEV_STATE_INIT;
dev_dbg(psp->dev, "SEV firmware initialized\n");
return rc;
}
int sev_platform_init(int *error)
{
int rc;
mutex_lock(&sev_cmd_mutex);
rc = __sev_platform_init_locked(error);
mutex_unlock(&sev_cmd_mutex);
return rc;
}
EXPORT_SYMBOL_GPL(sev_platform_init);
static int __sev_platform_shutdown_locked(int *error)
{
int ret;
ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, NULL, error);
if (ret)
return ret;
psp_master->sev_state = SEV_STATE_UNINIT;
dev_dbg(psp_master->dev, "SEV firmware shutdown\n");
return ret;
}
static int sev_platform_shutdown(int *error)
{
int rc;
mutex_lock(&sev_cmd_mutex);
rc = __sev_platform_shutdown_locked(NULL);
mutex_unlock(&sev_cmd_mutex);
return rc;
}
static int sev_get_platform_state(int *state, int *error)
{
int rc;
rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS,
&psp_master->status_cmd_buf, error);
if (rc)
return rc;
*state = psp_master->status_cmd_buf.state;
return rc;
}
static int sev_ioctl_do_reset(struct sev_issue_cmd *argp)
{
int state, rc;
/*
* The SEV spec requires that FACTORY_RESET must be issued in
* UNINIT state. Before we go further lets check if any guest is
* active.
*
* If FW is in WORKING state then deny the request otherwise issue
* SHUTDOWN command do INIT -> UNINIT before issuing the FACTORY_RESET.
*
*/
rc = sev_get_platform_state(&state, &argp->error);
if (rc)
return rc;
if (state == SEV_STATE_WORKING)
return -EBUSY;
if (state == SEV_STATE_INIT) {
rc = __sev_platform_shutdown_locked(&argp->error);
if (rc)
return rc;
}
return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, NULL, &argp->error);
}
static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
{
struct sev_user_data_status *data = &psp_master->status_cmd_buf;
int ret;
ret = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, data, &argp->error);
if (ret)
return ret;
if (copy_to_user((void __user *)argp->data, data, sizeof(*data)))
ret = -EFAULT;
return ret;
}
static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp)
{
int rc;
if (psp_master->sev_state == SEV_STATE_UNINIT) {
rc = __sev_platform_init_locked(&argp->error);
if (rc)
return rc;
}
return __sev_do_cmd_locked(cmd, NULL, &argp->error);
}
static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp)
{
struct sev_user_data_pek_csr input;
struct sev_data_pek_csr *data;
void *blob = NULL;
int ret;
if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
return -EFAULT;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
/* userspace wants to query CSR length */
if (!input.address || !input.length)
goto cmd;
/* allocate a physically contiguous buffer to store the CSR blob */
if (!access_ok(VERIFY_WRITE, input.address, input.length) ||
input.length > SEV_FW_BLOB_MAX_SIZE) {
ret = -EFAULT;
goto e_free;
}
blob = kmalloc(input.length, GFP_KERNEL);
if (!blob) {
ret = -ENOMEM;
goto e_free;
}
data->address = __psp_pa(blob);
data->len = input.length;
cmd:
if (psp_master->sev_state == SEV_STATE_UNINIT) {
ret = __sev_platform_init_locked(&argp->error);
if (ret)
goto e_free_blob;
}
ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, data, &argp->error);
/* If we query the CSR length, FW responded with expected data. */
input.length = data->len;
if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
ret = -EFAULT;
goto e_free_blob;
}
if (blob) {
if (copy_to_user((void __user *)input.address, blob, input.length))
ret = -EFAULT;
}
e_free_blob:
kfree(blob);
e_free:
kfree(data);
return ret;
}
void *psp_copy_user_blob(u64 __user uaddr, u32 len)
{
if (!uaddr || !len)
return ERR_PTR(-EINVAL);
/* verify that blob length does not exceed our limit */
if (len > SEV_FW_BLOB_MAX_SIZE)
return ERR_PTR(-EINVAL);
return memdup_user((void __user *)(uintptr_t)uaddr, len);
}
EXPORT_SYMBOL_GPL(psp_copy_user_blob);
static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp)
{
struct sev_user_data_pek_cert_import input;
struct sev_data_pek_cert_import *data;
void *pek_blob, *oca_blob;
int ret;
if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
return -EFAULT;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
/* copy PEK certificate blobs from userspace */
pek_blob = psp_copy_user_blob(input.pek_cert_address, input.pek_cert_len);
if (IS_ERR(pek_blob)) {
ret = PTR_ERR(pek_blob);
goto e_free;
}
data->pek_cert_address = __psp_pa(pek_blob);
data->pek_cert_len = input.pek_cert_len;
/* copy PEK certificate blobs from userspace */
oca_blob = psp_copy_user_blob(input.oca_cert_address, input.oca_cert_len);
if (IS_ERR(oca_blob)) {
ret = PTR_ERR(oca_blob);
goto e_free_pek;
}
data->oca_cert_address = __psp_pa(oca_blob);
data->oca_cert_len = input.oca_cert_len;
/* If platform is not in INIT state then transition it to INIT */
if (psp_master->sev_state != SEV_STATE_INIT) {
ret = __sev_platform_init_locked(&argp->error);
if (ret)
goto e_free_oca;
}
ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, data, &argp->error);
e_free_oca:
kfree(oca_blob);
e_free_pek:
kfree(pek_blob);
e_free:
kfree(data);
return ret;
}
static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp)
{
struct sev_user_data_pdh_cert_export input;
void *pdh_blob = NULL, *cert_blob = NULL;
struct sev_data_pdh_cert_export *data;
int ret;
if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
return -EFAULT;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
/* Userspace wants to query the certificate length. */
if (!input.pdh_cert_address ||
!input.pdh_cert_len ||
!input.cert_chain_address)
goto cmd;
/* Allocate a physically contiguous buffer to store the PDH blob. */
if ((input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) ||
!access_ok(VERIFY_WRITE, input.pdh_cert_address, input.pdh_cert_len)) {
ret = -EFAULT;
goto e_free;
}
/* Allocate a physically contiguous buffer to store the cert chain blob. */
if ((input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) ||
!access_ok(VERIFY_WRITE, input.cert_chain_address, input.cert_chain_len)) {
ret = -EFAULT;
goto e_free;
}
pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL);
if (!pdh_blob) {
ret = -ENOMEM;
goto e_free;
}
data->pdh_cert_address = __psp_pa(pdh_blob);
data->pdh_cert_len = input.pdh_cert_len;
cert_blob = kmalloc(input.cert_chain_len, GFP_KERNEL);
if (!cert_blob) {
ret = -ENOMEM;
goto e_free_pdh;
}
data->cert_chain_address = __psp_pa(cert_blob);
data->cert_chain_len = input.cert_chain_len;
cmd:
/* If platform is not in INIT state then transition it to INIT. */
if (psp_master->sev_state != SEV_STATE_INIT) {
ret = __sev_platform_init_locked(&argp->error);
if (ret)
goto e_free_cert;
}
ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, data, &argp->error);
/* If we query the length, FW responded with expected data. */
input.cert_chain_len = data->cert_chain_len;
input.pdh_cert_len = data->pdh_cert_len;
if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
ret = -EFAULT;
goto e_free_cert;
}
if (pdh_blob) {
if (copy_to_user((void __user *)input.pdh_cert_address,
pdh_blob, input.pdh_cert_len)) {
ret = -EFAULT;
goto e_free_cert;
}
}
if (cert_blob) {
if (copy_to_user((void __user *)input.cert_chain_address,
cert_blob, input.cert_chain_len))
ret = -EFAULT;
}
e_free_cert:
kfree(cert_blob);
e_free_pdh:
kfree(pdh_blob);
e_free:
kfree(data);
return ret;
}
static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct sev_issue_cmd input;
int ret = -EFAULT;
if (!psp_master)
return -ENODEV;
if (ioctl != SEV_ISSUE_CMD)
return -EINVAL;
if (copy_from_user(&input, argp, sizeof(struct sev_issue_cmd)))
return -EFAULT;
if (input.cmd > SEV_MAX)
return -EINVAL;
mutex_lock(&sev_cmd_mutex);
switch (input.cmd) {
case SEV_FACTORY_RESET:
ret = sev_ioctl_do_reset(&input);
break;
case SEV_PLATFORM_STATUS:
ret = sev_ioctl_do_platform_status(&input);
break;
case SEV_PEK_GEN:
ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PEK_GEN, &input);
break;
case SEV_PDH_GEN:
ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PDH_GEN, &input);
break;
case SEV_PEK_CSR:
ret = sev_ioctl_do_pek_csr(&input);
break;
case SEV_PEK_CERT_IMPORT:
ret = sev_ioctl_do_pek_import(&input);
break;
case SEV_PDH_CERT_EXPORT:
ret = sev_ioctl_do_pdh_export(&input);
break;
default:
ret = -EINVAL;
goto out;
}
if (copy_to_user(argp, &input, sizeof(struct sev_issue_cmd)))
ret = -EFAULT;
out:
mutex_unlock(&sev_cmd_mutex);
return ret;
}
static const struct file_operations sev_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = sev_ioctl,
};
int sev_platform_status(struct sev_user_data_status *data, int *error)
{
return sev_do_cmd(SEV_CMD_PLATFORM_STATUS, data, error);
}
EXPORT_SYMBOL_GPL(sev_platform_status);
int sev_guest_deactivate(struct sev_data_deactivate *data, int *error)
{
return sev_do_cmd(SEV_CMD_DEACTIVATE, data, error);
}
EXPORT_SYMBOL_GPL(sev_guest_deactivate);
int sev_guest_activate(struct sev_data_activate *data, int *error)
{
return sev_do_cmd(SEV_CMD_ACTIVATE, data, error);
}
EXPORT_SYMBOL_GPL(sev_guest_activate);
int sev_guest_decommission(struct sev_data_decommission *data, int *error)
{
return sev_do_cmd(SEV_CMD_DECOMMISSION, data, error);
}
EXPORT_SYMBOL_GPL(sev_guest_decommission);
int sev_guest_df_flush(int *error)
{
return sev_do_cmd(SEV_CMD_DF_FLUSH, NULL, error);
}
EXPORT_SYMBOL_GPL(sev_guest_df_flush);
static void sev_exit(struct kref *ref)
{
struct sev_misc_dev *misc_dev = container_of(ref, struct sev_misc_dev, refcount);
misc_deregister(&misc_dev->misc);
}
static int sev_misc_init(struct psp_device *psp)
{
struct device *dev = psp->dev;
int ret;
/*
* SEV feature support can be detected on multiple devices but the SEV
* FW commands must be issued on the master. During probe, we do not
* know the master hence we create /dev/sev on the first device probe.
* sev_do_cmd() finds the right master device to which to issue the
* command to the firmware.
*/
if (!misc_dev) {
struct miscdevice *misc;
misc_dev = devm_kzalloc(dev, sizeof(*misc_dev), GFP_KERNEL);
if (!misc_dev)
return -ENOMEM;
misc = &misc_dev->misc;
misc->minor = MISC_DYNAMIC_MINOR;
misc->name = DEVICE_NAME;
misc->fops = &sev_fops;
ret = misc_register(misc);
if (ret)
return ret;
kref_init(&misc_dev->refcount);
} else {
kref_get(&misc_dev->refcount);
}
init_waitqueue_head(&psp->sev_int_queue);
psp->sev_misc = misc_dev;
dev_dbg(dev, "registered SEV device\n");
return 0;
}
static int sev_init(struct psp_device *psp)
{
/* Check if device supports SEV feature */
if (!(ioread32(psp->io_regs + PSP_FEATURE_REG) & 1)) {
dev_dbg(psp->dev, "device does not support SEV\n");
return 1;
}
return sev_misc_init(psp);
}
int psp_dev_init(struct sp_device *sp)
{
struct device *dev = sp->dev;
struct psp_device *psp;
int ret;
ret = -ENOMEM;
psp = psp_alloc_struct(sp);
if (!psp)
goto e_err;
sp->psp_data = psp;
psp->vdata = (struct psp_vdata *)sp->dev_vdata->psp_vdata;
if (!psp->vdata) {
ret = -ENODEV;
dev_err(dev, "missing driver data\n");
goto e_err;
}
psp->io_regs = sp->io_map + psp->vdata->offset;
/* Disable and clear interrupts until ready */
iowrite32(0, psp->io_regs + PSP_P2CMSG_INTEN);
iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTSTS);
/* Request an irq */
ret = sp_request_psp_irq(psp->sp, psp_irq_handler, psp->name, psp);
if (ret) {
dev_err(dev, "psp: unable to allocate an IRQ\n");
goto e_err;
}
ret = sev_init(psp);
if (ret)
goto e_irq;
if (sp->set_psp_master_device)
sp->set_psp_master_device(sp);
/* Enable interrupt */
iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTEN);
return 0;
e_irq:
sp_free_psp_irq(psp->sp, psp);
e_err:
sp->psp_data = NULL;
dev_notice(dev, "psp initialization failed\n");
return ret;
}
void psp_dev_destroy(struct sp_device *sp)
{
struct psp_device *psp = sp->psp_data;
if (psp->sev_misc)
kref_put(&misc_dev->refcount, sev_exit);
sp_free_psp_irq(sp, psp);
}
int sev_issue_cmd_external_user(struct file *filep, unsigned int cmd,
void *data, int *error)
{
if (!filep || filep->f_op != &sev_fops)
return -EBADF;
return sev_do_cmd(cmd, data, error);
}
EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
void psp_pci_init(void)
{
struct sev_user_data_status *status;
struct sp_device *sp;
int error, rc;
sp = sp_get_psp_master_device();
if (!sp)
return;
psp_master = sp->psp_data;
/* Initialize the platform */
rc = sev_platform_init(&error);
if (rc) {
dev_err(sp->dev, "SEV: failed to INIT error %#x\n", error);
goto err;
}
/* Display SEV firmware version */
status = &psp_master->status_cmd_buf;
rc = sev_platform_status(status, &error);
if (rc) {
dev_err(sp->dev, "SEV: failed to get status error %#x\n", error);
goto err;
}
dev_info(sp->dev, "SEV API:%d.%d build:%d\n", status->api_major,
status->api_minor, status->build);
return;
err:
psp_master = NULL;
}
void psp_pci_exit(void)
{
if (!psp_master)
return;
sev_platform_shutdown(NULL);
}