Re: [PATCH v2 2/6] fpga: m10bmc-sec: create max10 bmc security engine
From: Russ Weight
Date: Thu Oct 08 2020 - 17:12:48 EST
On 10/6/20 10:31 AM, Tom Rix wrote:
> On 10/2/20 6:24 PM, Russ Weight wrote:
>> Create a platform driver that can be invoked as a sub
>> driver for the Intel MAX10 BMC in order to support
>> secure updates. This sub-driver will invoke an
>> instance of the Intel FPGA Security Manager class driver
>> in order to expose sysfs interfaces for managing and
>> monitoring secure updates to FPGA and BMC images.
>>
>> This patch creates the MAX10 BMC Security Engine driver and
>> provides support for displaying the current root entry hashes
>> for the FPGA static region, the FPGA PR region, and the MAX10
>> BMC.
>>
>> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
>> ---
>> v2:
>> - Added drivers/fpga/intel-m10-bmc-secure.c file to MAINTAINERS.
>> - Switched to GENMASK(31, 16) for a couple of mask definitions.
>> - Moved MAX10 BMC address and function definitions to a separate
>> patch.
>> - Replaced small function-creation macros with explicit function
>> declarations.
>> - Removed ifpga_sec_mgr_init() and ifpga_sec_mgr_uinit() functions.
>> - Adapted to changes in the Intel FPGA Security Manager by splitting
>> the single call to ifpga_sec_mgr_register() into two function
>> calls: devm_ifpga_sec_mgr_create() and ifpga_sec_mgr_register().
>> ---
>> MAINTAINERS | 1 +
>> drivers/fpga/Kconfig | 11 ++
>> drivers/fpga/Makefile | 3 +
>> drivers/fpga/intel-m10-bmc-secure.c | 165 ++++++++++++++++++++++++++++
>> 4 files changed, 180 insertions(+)
>> create mode 100644 drivers/fpga/intel-m10-bmc-secure.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 0bb5ef309dec..c359d0214980 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -6898,6 +6898,7 @@ S: Maintained
>> F: Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>> F: Documentation/fpga/ifpga-sec-mgr.rst
>> F: drivers/fpga/ifpga-sec-mgr.c
>> +F: drivers/fpga/intel-m10-bmc-secure.c
>> F: include/linux/fpga/ifpga-sec-mgr.h
>>
>> FPU EMULATOR
>> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
>> index c534cc80f398..2380d36b08c7 100644
>> --- a/drivers/fpga/Kconfig
>> +++ b/drivers/fpga/Kconfig
>> @@ -235,4 +235,15 @@ config IFPGA_SEC_MGR
>> region and for the BMC. Select this option to enable
>> updates for secure FPGA devices.
>>
>> +config IFPGA_M10_BMC_SECURE
>> + tristate "Intel MAX10 BMC security engine"
>> + depends on MFD_INTEL_M10_BMC && IFPGA_SEC_MGR
>> + help
>> + Secure update support for the Intel MAX10 board management
>> + controller.
>> +
>> + This is a subdriver of the Intel MAX10 board management controller
>> + (BMC) and provides support for secure updates for the BMC image,
>> + the FPGA image, the Root Entry Hashes, etc.
>> +
>> endif # FPGA
>> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
>> index 6f706590e209..8e702689cdda 100644
>> --- a/drivers/fpga/Makefile
>> +++ b/drivers/fpga/Makefile
>> @@ -24,6 +24,9 @@ obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT) += altera-pr-ip-core-plat.o
>> # Intel FPGA Security Manager Framework
>> obj-$(CONFIG_IFPGA_SEC_MGR) += ifpga-sec-mgr.o
>>
>> +# Intel Security Manager Drivers
>> +obj-$(CONFIG_IFPGA_M10_BMC_SECURE) += intel-m10-bmc-secure.o
>> +
>> # FPGA Bridge Drivers
>> obj-$(CONFIG_FPGA_BRIDGE) += fpga-bridge.o
>> obj-$(CONFIG_SOCFPGA_FPGA_BRIDGE) += altera-hps2fpga.o altera-fpga2sdram.o
>> diff --git a/drivers/fpga/intel-m10-bmc-secure.c b/drivers/fpga/intel-m10-bmc-secure.c
>> new file mode 100644
>> index 000000000000..df8ebda9a9cb
>> --- /dev/null
>> +++ b/drivers/fpga/intel-m10-bmc-secure.c
>> @@ -0,0 +1,165 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Intel Max10 Board Management Controller Security Engine Driver
>> + *
>> + * Copyright (C) 2019-2020 Intel Corporation. All rights reserved.
>> + *
>> + */
>> +#include <linux/bitfield.h>
>> +#include <linux/device.h>
>> +#include <linux/fpga/ifpga-sec-mgr.h>
>> +#include <linux/mfd/intel-m10-bmc.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/vmalloc.h>
>> +
>> +struct m10bmc_sec {
>> + struct device *dev;
>> + struct intel_m10bmc *m10bmc;
>> + struct ifpga_sec_mgr *imgr;
>> +};
>> +
>> +#define REH_SHA256_SIZE 32
>> +#define REH_SHA384_SIZE 48
>> +#define REH_MAGIC GENMASK(15, 0)
>> +#define REH_SHA_NUM_BYTES GENMASK(31, 16)
>> +
>> +static int m10bmc_reh_size(struct ifpga_sec_mgr *imgr,
>> + u32 exp_magic, u32 prog_addr)
>> +{
>> + struct m10bmc_sec *sec = imgr->priv;
>> + int sha_num_bytes, ret;
>> + u32 magic;
>> +
>> + ret = m10bmc_raw_read(sec->m10bmc, prog_addr, &magic);
>> + if (ret)
>> + return ret;
>> +
>> + dev_dbg(sec->dev, "%s magic 0x%08x\n", __func__, magic);
>> +
>> + /*
>> + * If no magic number, then no REH is programmed, so
>> + * the REH size is zero.
>> + */
>> + if (FIELD_GET(REH_MAGIC, magic) != exp_magic)
>> + return 0;
>> +
>> + sha_num_bytes = FIELD_GET(REH_SHA_NUM_BYTES, magic) / 8;
>> + if (sha_num_bytes != REH_SHA256_SIZE &&
>> + sha_num_bytes != REH_SHA384_SIZE) {
>> + dev_err(sec->dev, "%s bad sha num bytes %d\n", __func__,
>> + sha_num_bytes);
>> + return -EINVAL;
>> + }
>> +
>> + return sha_num_bytes;
>> +}
>> +
>> +static int m10bmc_bmc_reh_size(struct ifpga_sec_mgr *imgr)
> For naming consistency, the _reh_ vs _root_entry_hash_
>
> pick one.
>
> If you pick _reh_ put a comment at the top since reh isn't a familiar acronym (at least to me)
OK - I'll go with reh and put a comment at the beginning of the REH support.
>
>> +{
>> + return m10bmc_reh_size(imgr, BMC_PROG_MAGIC, BMC_PROG_ADDR);
>> +}
>> +
>> +static int m10bmc_sr_reh_size(struct ifpga_sec_mgr *imgr)
>> +{
>> + return m10bmc_reh_size(imgr, SR_PROG_MAGIC, SR_PROG_ADDR);
>> +}
>> +
>> +static int m10bmc_pr_reh_size(struct ifpga_sec_mgr *imgr)
>> +{
>> + return m10bmc_reh_size(imgr, PR_PROG_MAGIC, PR_PROG_ADDR);
>> +}
>> +
>> +static int m10bmc_root_entry_hash(struct ifpga_sec_mgr *imgr,
>> + u32 hash_addr, u8 *hash,
>> + unsigned int size)
>> +{
>> + struct m10bmc_sec *sec = imgr->priv;
>> + unsigned int stride = regmap_get_reg_stride(sec->m10bmc->regmap);
>> + int ret;
>> +
>> + ret = m10bmc_raw_bulk_read(sec->m10bmc, hash_addr,
>> + hash, size / stride);
>> + if (ret)
>> + dev_err(sec->dev, "bulk_read of 0x%x failed %d",
>> + hash_addr, ret);
>> +
>> + return ret;
>> +}
>> +
>> +static int m10bmc_bmc_root_entry_hash(struct ifpga_sec_mgr *imgr,
>> + u8 *hash, unsigned int size)
>> +{
>> + return m10bmc_root_entry_hash(imgr, BMC_REH_ADDR, hash, size);
>> +}
>> +
>> +static int m10bmc_sr_root_entry_hash(struct ifpga_sec_mgr *imgr,
>> + u8 *hash, unsigned int size)
>> +{
>> + return m10bmc_root_entry_hash(imgr, SR_REH_ADDR, hash, size);
>> +}
>> +
>> +static int m10bmc_pr_root_entry_hash(struct ifpga_sec_mgr *imgr,
>> + u8 *hash, unsigned int size)
>> +{
>> + return m10bmc_root_entry_hash(imgr, PR_REH_ADDR, hash, size);
>> +}
>> +
>> +static const struct ifpga_sec_mgr_ops m10bmc_iops = {
>> + .bmc_root_entry_hash = m10bmc_bmc_root_entry_hash,
>> + .sr_root_entry_hash = m10bmc_sr_root_entry_hash,
>> + .pr_root_entry_hash = m10bmc_pr_root_entry_hash,
>> + .bmc_reh_size = m10bmc_bmc_reh_size,
>> + .sr_reh_size = m10bmc_sr_reh_size,
>> + .pr_reh_size = m10bmc_pr_reh_size,
>> +};
>> +
>> +static int m10bmc_secure_probe(struct platform_device *pdev)
>> +{
>> + struct ifpga_sec_mgr *imgr;
>> + struct m10bmc_sec *sec;
>> + int ret;
>> +
>> + sec = devm_kzalloc(&pdev->dev, sizeof(*sec), GFP_KERNEL);
>> + if (!sec)
>> + return -ENOMEM;
>> +
>> + sec->dev = &pdev->dev;
>> + sec->m10bmc = dev_get_drvdata(pdev->dev.parent);
>> + dev_set_drvdata(&pdev->dev, sec);
>> +
>> + imgr = devm_ifpga_sec_mgr_create(sec->dev, "Max10 BMC Security Manager",
>> + &m10bmc_iops, sec);
>> + if (!imgr) {
>> + dev_err(sec->dev,
>> + "Security manager failed to start: %d\n", ret);
>> + return -ENOMEM;
>> + }
>> +
>> + sec->imgr = imgr;
>> +
>> + return ifpga_sec_mgr_register(imgr);
>> +}
>> +
>> +static int m10bmc_secure_remove(struct platform_device *pdev)
>> +{
>> + struct m10bmc_sec *sec = dev_get_drvdata(&pdev->dev);
>> +
>> + ifpga_sec_mgr_unregister(sec->imgr);
>> +
>> + return 0;
>> +}
>> +
>> +static struct platform_driver intel_m10bmc_secure_driver = {
>> + .probe = m10bmc_secure_probe,
>> + .remove = m10bmc_secure_remove,
>> + .driver = {
>> + .name = "n3000bmc-secure",
>> + },
>> +};
>> +module_platform_driver(intel_m10bmc_secure_driver);
>> +
>> +MODULE_ALIAS("platform:n3000bmc-secure");
>> +MODULE_AUTHOR("Intel Corporation");
>> +MODULE_DESCRIPTION("Intel MAX10 BMC secure engine");
> Maybe "... secure update"
Yeah - that sounds better.
Thanks,
- Russ
>
> Tom
>
>> +MODULE_LICENSE("GPL v2");