From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Component Measurement and Authentication (CMA, PCIe r6.2 sec 6.31) allows for measurement and authentication of PCIe devices. It is based on the Security Protocol and Data Model specification (SPDM, https://www.dmtf.org/dsp/DSP0274). CMA-SPDM in turn forms the basis for Integrity and Data Encryption (IDE, PCIe r6.2 sec 6.33) because the key material used by IDE is transmitted over a CMA-SPDM session. As a first step, authenticate CMA-capable devices on enumeration. A subsequent commit will expose the result in sysfs. When allocating SPDM session state with spdm_create(), the maximum SPDM message length needs to be passed. Make the PCI_DOE_MAX_LENGTH macro public and calculate the maximum payload length from it. Credits: Jonathan wrote a proof-of-concept of this CMA implementation. Lukas reworked it for upstream. Wilfred contributed fixes for issues discovered during testing. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Co-developed-by: Wilfred Mallawa <wilfred.mallawa@xxxxxxx> Signed-off-by: Wilfred Mallawa <wilfred.mallawa@xxxxxxx> Co-developed-by: Lukas Wunner <lukas@xxxxxxxxx> Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> --- MAINTAINERS | 1 + drivers/pci/Kconfig | 13 ++++++ drivers/pci/Makefile | 2 + drivers/pci/cma.c | 100 ++++++++++++++++++++++++++++++++++++++++ drivers/pci/doe.c | 3 -- drivers/pci/pci.h | 8 ++++ drivers/pci/probe.c | 1 + drivers/pci/remove.c | 1 + include/linux/pci-doe.h | 4 ++ include/linux/pci.h | 4 ++ 10 files changed, 134 insertions(+), 3 deletions(-) create mode 100644 drivers/pci/cma.c diff --git a/MAINTAINERS b/MAINTAINERS index dbe16eea8818..9aad3350da16 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -20153,6 +20153,7 @@ L: linux-cxl@xxxxxxxxxxxxxxx L: linux-pci@xxxxxxxxxxxxxxx S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/devsec/spdm.git +F: drivers/pci/cma* F: include/linux/spdm.h F: lib/spdm/ diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index d35001589d88..f656211d707a 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -121,6 +121,19 @@ config XEN_PCIDEV_FRONTEND config PCI_ATS bool +config PCI_CMA + bool "Component Measurement and Authentication (CMA-SPDM)" + select CRYPTO_ECDSA + select CRYPTO_RSA + select CRYPTO_SHA256 + select CRYPTO_SHA512 + select PCI_DOE + select SPDM + help + Authenticate devices on enumeration per PCIe r6.2 sec 6.31. + A PCI DOE mailbox is used as transport for DMTF SPDM based + authentication, measurement and secure channel establishment. + config PCI_DOE bool diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index 175302036890..6bcfeb698961 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -35,6 +35,8 @@ obj-$(CONFIG_VGA_ARB) += vgaarb.o obj-$(CONFIG_PCI_DOE) += doe.o obj-$(CONFIG_PCI_DYNAMIC_OF_NODES) += of_property.o +obj-$(CONFIG_PCI_CMA) += cma.o + # Endpoint library must be initialized before its users obj-$(CONFIG_PCI_ENDPOINT) += endpoint/ diff --git a/drivers/pci/cma.c b/drivers/pci/cma.c new file mode 100644 index 000000000000..275338b95640 --- /dev/null +++ b/drivers/pci/cma.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Component Measurement and Authentication (CMA-SPDM, PCIe r6.2 sec 6.31) + * + * Copyright (C) 2021 Huawei + * Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> + * + * Copyright (C) 2022-24 Intel Corporation + */ + +#define dev_fmt(fmt) "CMA: " fmt + +#include <linux/pci.h> +#include <linux/pci-doe.h> +#include <linux/pm_runtime.h> +#include <linux/spdm.h> + +#include "pci.h" + +/* Keyring that userspace can poke certs into */ +static struct key *pci_cma_keyring; + +#define PCI_DOE_FEATURE_CMA 1 + +static ssize_t pci_doe_transport(void *priv, struct device *dev, + const void *request, size_t request_sz, + void *response, size_t response_sz) +{ + struct pci_doe_mb *doe = priv; + ssize_t rc; + + /* + * CMA-SPDM operation in non-D0 states is optional (PCIe r6.2 + * sec 6.31.3). The spec does not define a way to determine + * if it's supported, so resume to D0 unconditionally. + */ + rc = pm_runtime_resume_and_get(dev); + if (rc) + return rc; + + rc = pci_doe(doe, PCI_VENDOR_ID_PCI_SIG, PCI_DOE_FEATURE_CMA, + request, request_sz, response, response_sz); + + pm_runtime_put(dev); + + return rc; +} + +void pci_cma_init(struct pci_dev *pdev) +{ + struct pci_doe_mb *doe; + + if (IS_ERR(pci_cma_keyring)) + return; + + if (!pci_is_pcie(pdev)) + return; + + doe = pci_find_doe_mailbox(pdev, PCI_VENDOR_ID_PCI_SIG, + PCI_DOE_FEATURE_CMA); + if (!doe) + return; + + pdev->spdm_state = spdm_create(&pdev->dev, pci_doe_transport, doe, + PCI_DOE_MAX_PAYLOAD, pci_cma_keyring); + if (!pdev->spdm_state) + return; + + /* + * Keep spdm_state allocated even if initial authentication fails + * to allow for provisioning of certificates and reauthentication. + */ + spdm_authenticate(pdev->spdm_state); +} + +void pci_cma_destroy(struct pci_dev *pdev) +{ + if (!pdev->spdm_state) + return; + + spdm_destroy(pdev->spdm_state); +} + +__init static int pci_cma_keyring_init(void) +{ + pci_cma_keyring = keyring_alloc(".cma", KUIDT_INIT(0), KGIDT_INIT(0), + current_cred(), + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ | + KEY_USR_WRITE | KEY_USR_SEARCH, + KEY_ALLOC_NOT_IN_QUOTA | + KEY_ALLOC_SET_KEEP, NULL, NULL); + if (IS_ERR(pci_cma_keyring)) { + pr_err("PCI: Could not allocate .cma keyring\n"); + return PTR_ERR(pci_cma_keyring); + } + + return 0; +} +arch_initcall(pci_cma_keyring_init); diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c index 652d63df9d22..34bb8f232799 100644 --- a/drivers/pci/doe.c +++ b/drivers/pci/doe.c @@ -31,9 +31,6 @@ #define PCI_DOE_FLAG_CANCEL 0 #define PCI_DOE_FLAG_DEAD 1 -/* Max data object length is 2^18 dwords */ -#define PCI_DOE_MAX_LENGTH (1 << 18) - /** * struct pci_doe_mb - State for a single DOE mailbox * diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index fd44565c4756..fc90845caf83 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -333,6 +333,14 @@ static inline void pci_doe_destroy(struct pci_dev *pdev) { } static inline void pci_doe_disconnected(struct pci_dev *pdev) { } #endif +#ifdef CONFIG_PCI_CMA +void pci_cma_init(struct pci_dev *pdev); +void pci_cma_destroy(struct pci_dev *pdev); +#else +static inline void pci_cma_init(struct pci_dev *pdev) { } +static inline void pci_cma_destroy(struct pci_dev *pdev) { } +#endif + /** * pci_dev_set_io_state - Set the new error state if possible. * diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 8e696e547565..5297f9a08ca2 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2484,6 +2484,7 @@ static void pci_init_capabilities(struct pci_dev *dev) pci_dpc_init(dev); /* Downstream Port Containment */ pci_rcec_init(dev); /* Root Complex Event Collector */ pci_doe_init(dev); /* Data Object Exchange */ + pci_cma_init(dev); /* Component Measurement & Auth */ pcie_report_downtraining(dev); pci_init_reset_methods(dev); diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index d749ea8250d6..f009ac578997 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -39,6 +39,7 @@ static void pci_destroy_dev(struct pci_dev *dev) list_del(&dev->bus_list); up_write(&pci_bus_sem); + pci_cma_destroy(dev); pci_doe_destroy(dev); pcie_aspm_exit_link_state(dev); pci_bridge_d3_update(dev); diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h index 1f14aed4354b..0d3d7656c456 100644 --- a/include/linux/pci-doe.h +++ b/include/linux/pci-doe.h @@ -15,6 +15,10 @@ struct pci_doe_mb; +/* Max data object length is 2^18 dwords (including 2 dwords for header) */ +#define PCI_DOE_MAX_LENGTH (1 << 18) +#define PCI_DOE_MAX_PAYLOAD ((PCI_DOE_MAX_LENGTH - 2) * sizeof(u32)) + struct pci_doe_mb *pci_find_doe_mailbox(struct pci_dev *pdev, u16 vendor, u8 type); diff --git a/include/linux/pci.h b/include/linux/pci.h index fb004fd4e889..cb2a0be57196 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -39,6 +39,7 @@ #include <linux/io.h> #include <linux/resource_ext.h> #include <linux/msi_api.h> +#include <linux/spdm.h> #include <uapi/linux/pci.h> #include <linux/pci_ids.h> @@ -517,6 +518,9 @@ struct pci_dev { #endif #ifdef CONFIG_PCI_DOE struct xarray doe_mbs; /* Data Object Exchange mailboxes */ +#endif +#ifdef CONFIG_PCI_CMA + struct spdm_state *spdm_state; /* Security Protocol and Data Model */ #endif u16 acs_cap; /* ACS Capability offset */ phys_addr_t rom; /* Physical address if not from BAR */ -- 2.43.0
