On Thu, 5 Aug 2021 00:18:38 +0800
Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote:
> This currently very much a PoC. Currently the SPDM library only provides
> a single function to allow a challenge / authentication of the PCI EP.
>
> SPDM exchanges must occur in one of a small set of valid squences over
> which the message digest used in authentication is built up.
> Placing that complexity in the SPDM library seems like a good way
> to enforce that logic, without having to do it for each transport.
>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
This is far more likely to work if I actually include the missing drivers/pci/cma.c
I'll send a v2 next week, but in the meantime it should look like this.
From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
To: <jonathan.cameron@xxxxxxxxxx>
Subject: [PATCH] pci/cma: Missing file
Date: Sat, 18 Sep 2021 00:16:00 +0800
X-Mailer: git-send-email 2.19.1
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/pci/cma.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 102 insertions(+)
diff --git a/drivers/pci/cma.c b/drivers/pci/cma.c
new file mode 100644
index 000000000000..58fef73674fe
--- /dev/null
+++ b/drivers/pci/cma.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Component Measurement and Authentication was added as an ECN to the
+ * PCIe r5.0 spec.
+ *
+ * Copyright (C) 2021 Huawei
+ * Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pci-cma.h>
+#include <linux/pci-doe.h>
+#include <linux/spdm.h>
+
+/* Keyring that userspace can poke certs into */
+static struct key *cma_keyring;
+
+static int cma_spdm_ex(void *priv, struct spdm_exchange *spdm_ex)
+{
+ size_t request_padded_sz, response_padded_sz;
+ struct pci_doe_exchange ex = {
+ .vid = PCI_VENDOR_ID_PCI_SIG,
+ .protocol = PCI_DOE_PROTOCOL_CMA,
+ };
+ struct pci_doe *doe = priv;
+ int rc;
+
+ /* DOE requires that response and request are padded to a multiple of 4 bytes */
+ request_padded_sz = ALIGN(spdm_ex->request_pl_sz, sizeof(u32));
+ if (request_padded_sz != spdm_ex->request_pl_sz) {
+ ex.request_pl = kzalloc(request_padded_sz, GFP_KERNEL);
+ if (!ex.request_pl)
+ return -ENOMEM;
+ memcpy(ex.request_pl, spdm_ex->request_pl, spdm_ex->request_pl_sz);
+ ex.request_pl_sz = request_padded_sz;
+ } else {
+ ex.request_pl = (u32 *)spdm_ex->request_pl;
+ ex.request_pl_sz = spdm_ex->request_pl_sz;
+ }
+
+ response_padded_sz = ALIGN(spdm_ex->response_pl_sz, sizeof(u32));
+ if (response_padded_sz != spdm_ex->response_pl_sz) {
+ ex.response_pl = kzalloc(response_padded_sz, GFP_KERNEL);
+ if (!ex.response_pl) {
+ rc = -ENOMEM;
+ goto err_free_req;
+ }
+ ex.response_pl_sz = response_padded_sz;
+ } else {
+ ex.response_pl = (u32 *)spdm_ex->response_pl;
+ ex.response_pl_sz = spdm_ex->response_pl_sz;
+ }
+
+ rc = pci_doe_exchange_sync(doe, &ex);
+ if (rc < 0)
+ goto err_free_rsp;
+
+ if (response_padded_sz != spdm_ex->response_pl_sz)
+ memcpy(spdm_ex->response_pl, ex.response_pl, spdm_ex->response_pl_sz);
+
+err_free_rsp:
+ if (response_padded_sz != spdm_ex->response_pl_sz)
+ kfree(ex.response_pl);
+err_free_req:
+ if (request_padded_sz != spdm_ex->request_pl_sz)
+ kfree(ex.request_pl);
+
+ return rc;
+}
+
+void pci_cma_init(struct pci_doe *doe, struct spdm_state *spdm_state)
+{
+ memset(spdm_state, 0, sizeof(*spdm_state));
+ spdm_state->transport_ex = cma_spdm_ex;
+ spdm_state->transport_priv = doe;
+ spdm_state->dev = &doe->pdev->dev;
+ spdm_state->root_keyring = cma_keyring;
+}
+EXPORT_SYMBOL_GPL(pci_cma_init);
+
+int pci_cma_authenticate(struct spdm_state *spdm_state)
+{
+ return spdm_authenticate(spdm_state);
+}
+EXPORT_SYMBOL_GPL(pci_cma_authenticate);
+
+__init static int cma_keyring_init(void)
+{
+ 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(cma_keyring))
+ pr_err("Could not allocate cma keyring\n");
+
+ return 0;
+}
+device_initcall(cma_keyring_init);
+MODULE_LICENSE("GPL v2");
--
2.19.1
> ---
> drivers/pci/Kconfig | 9 +++++++++
> drivers/pci/Makefile | 1 +
> drivers/pci/doe.c | 2 --
> include/linux/pci-doe.h | 2 ++
> 4 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index a30c59cf5e27..43e3b0d5e8cd 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -198,6 +198,15 @@ config PCI_DOE
> used by a number of different protocols.
> DOE is defined in the Data Object Exchange ECN to the PCIe r5.0 spec.
>
> +config PCI_CMA
> + tristate
> + select PCI_DOE
> + select ASN1_ENCODER
> + select SPDM
> + help
> + This enables library support for the PCI Component Measurement and
> + Authentication ECN. This uses DMTF SPDM 1.1
> +
> choice
> prompt "PCI Express hierarchy optimization setting"
> default PCIE_BUS_DEFAULT
> diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
> index 1b61c1a1c232..3f6b3543d565 100644
> --- a/drivers/pci/Makefile
> +++ b/drivers/pci/Makefile
> @@ -29,6 +29,7 @@ obj-$(CONFIG_PCI_PF_STUB) += pci-pf-stub.o
> obj-$(CONFIG_PCI_ECAM) += ecam.o
> obj-$(CONFIG_PCI_P2PDMA) += p2pdma.o
> obj-$(CONFIG_PCI_DOE) += doe.o
> +obj-$(CONFIG_PCI_CMA) += cma.o
> obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o
>
> # Endpoint library must be initialized before its users
> diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
> index 2d20f59e42c6..f6aaeed01010 100644
> --- a/drivers/pci/doe.c
> +++ b/drivers/pci/doe.c
> @@ -20,8 +20,6 @@
> /* Maximum number of DOE instances in the system */
> #define PCI_DOE_MAX_CNT 65536
>
> -#define PCI_DOE_PROTOCOL_DISCOVERY 0
> -
> #define PCI_DOE_BUSY_MAX_RETRIES 16
> #define PCI_DOE_POLL_INTERVAL (HZ / 128)
>
> diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h
> index bdc5f15f14ab..1347c124ed70 100644
> --- a/include/linux/pci-doe.h
> +++ b/include/linux/pci-doe.h
> @@ -19,6 +19,8 @@ struct pci_doe_prot {
> u8 type;
> };
>
> +#define PCI_DOE_PROTOCOL_DISCOVERY 0
> +#define PCI_DOE_PROTOCOL_CMA 1
> struct workqueue_struct;
>
> enum pci_doe_state {
