| Message ID | 7721bfa3b4f8a99a111f7808ad8890c3c13df56d.1695921657.git.lukas@wunner.de (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | PCI device authentication | expand |
On Thu, 28 Sep 2023 19:32:38 +0200 Lukas Wunner <lukas@wunner.de> wrote: > From: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > Component Measurement and Authentication (CMA, PCIe r6.1 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 r6.1 sec 6.33) because the key material used by IDE is > exchanged 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@huawei.com> > Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com> > Signed-off-by: Lukas Wunner <lukas@wunner.de> Hi Lukas, A few things inline. Biggest of which is making this one build warning free by pulling forward the cma_capable flag from patch 10. > > diff --git a/drivers/pci/cma.c b/drivers/pci/cma.c > new file mode 100644 > index 000000000000..06e5846325e3 > --- /dev/null > +++ b/drivers/pci/cma.c > +void pci_cma_init(struct pci_dev *pdev) > +{ > + struct pci_doe_mb *doe; > + int rc; > + > + if (!pci_cma_keyring) { > + return; > + } > + > + if (!pci_is_pcie(pdev)) > + return; > + > + doe = pci_find_doe_mailbox(pdev, PCI_VENDOR_ID_PCI_SIG, > + PCI_DOE_PROTOCOL_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; > + } Brackets not needed. > + > + rc = spdm_authenticate(pdev->spdm_state); Hanging rc? There is a blob in patch 10 that uses it, but odd to keep it around in meantime. Perhaps just add the flag in this patch and set it even though no one cares about it yet. > +} > + > +void pci_cma_destroy(struct pci_dev *pdev) > +{ > + if (pdev->spdm_state) > + 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("Could not allocate keyring\n"); > + return PTR_ERR(pci_cma_keyring); > + } > + > + return 0; > +} > +arch_initcall(pci_cma_keyring_init);
On Thu, Sep 28, 2023 at 07:32:38PM +0200, Lukas Wunner wrote: > From: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > Component Measurement and Authentication (CMA, PCIe r6.1 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). > +#define dev_fmt(fmt) "CMA: " fmt > +void pci_cma_init(struct pci_dev *pdev) > +{ > + struct pci_doe_mb *doe; > + int rc; > + > + if (!pci_cma_keyring) { > + return; > + } Jonathan mentioned the extra brackets below; here's another. > + if (!pdev->spdm_state) { > + return; > + } > + if (IS_ERR(pci_cma_keyring)) { > + pr_err("Could not allocate keyring\n"); There's a #define dev_fmt(fmt) above, but I don't think it's used in this patch. I think this would need something like: #define pr_fmt(fmt) "PCI: CMA: " fmt
diff --git a/MAINTAINERS b/MAINTAINERS index 2591d2217d65..70a2beb4a278 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19305,6 +19305,7 @@ M: Lukas Wunner <lukas@wunner.de> L: linux-cxl@vger.kernel.org L: linux-pci@vger.kernel.org S: Maintained +F: drivers/pci/cma* F: include/linux/spdm.h F: lib/spdm* diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index e9ae66cc4189..c9aa5253ac1f 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -116,6 +116,19 @@ 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_REQUESTER + help + Authenticate devices on enumeration per PCIe r6.1 sec 6.31. + A PCI DOE mailbox is used as transport for DMTF SPDM based + attestation, measurement and secure channel establishment. + config PCI_DOE bool diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index cc8b4e01e29d..e0705b82690b 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -34,6 +34,8 @@ 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..06e5846325e3 --- /dev/null +++ b/drivers/pci/cma.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Component Measurement and Authentication (CMA-SPDM, PCIe r6.1 sec 6.31) + * + * Copyright (C) 2021 Huawei + * Jonathan Cameron <Jonathan.Cameron@huawei.com> + * + * Copyright (C) 2022-23 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" + +#define PCI_DOE_PROTOCOL_CMA 1 + +/* Keyring that userspace can poke certs into */ +static struct key *pci_cma_keyring; + +static int 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; + int rc; + + /* + * CMA-SPDM operation in non-D0 states is optional (PCIe r6.1 + * 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_PROTOCOL_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; + int rc; + + if (!pci_cma_keyring) { + return; + } + + if (!pci_is_pcie(pdev)) + return; + + doe = pci_find_doe_mailbox(pdev, PCI_VENDOR_ID_PCI_SIG, + PCI_DOE_PROTOCOL_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; + } + + rc = spdm_authenticate(pdev->spdm_state); +} + +void pci_cma_destroy(struct pci_dev *pdev) +{ + if (pdev->spdm_state) + 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("Could not allocate 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 e3aab5edaf70..79f0336eb0c3 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 39a8932dc340..bd80a0369c9c 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -322,6 +322,14 @@ 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 795534589b98..1420a8d82386 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2487,6 +2487,7 @@ 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 8c7c2c3c6c65..0c0123317df6 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> @@ -515,6 +516,9 @@ 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 */