On Tue, 7 May 2024, David E. Box wrote: > Intel On Demand adds attestation and firmware measurement retrieval > services through use of the protocols defined the Security Protocols and > Data Measurement (SPDM) specification. SPDM messages exchanges are used to > authenticate On Demand hardware and to retrieve signed measurements of the > NVRAM state used to track feature provisioning and the NVRAM state used for > metering services. These allow software to verify the authenticity of the > On Demand hardware as well as the integrity of the reported silicon > configuration. > > Add an ioctl interface for sending SPDM messages through the On Demand > mailbox. Provides commands to get a list of SPDM enabled devices, get the > message size limits for SPDM Requesters and Responders, and perform an SPDM > message exchange. > > Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx> > Link: https://www.dmtf.org/sites/default/files/standards/documents/DSP0274_1.0.1.pdf [1] > --- > V2 > - Move size < 4 check into sdsi_spdm_exchange() and add comment > clarifying return values of that function. > - Use SZ_4K and add helpers > - Use devm_kasprintf() > - Remove unnecessary parens > - Use --attest for long option > > .../userspace-api/ioctl/ioctl-number.rst | 1 + > MAINTAINERS | 1 + > drivers/platform/x86/intel/sdsi.c | 210 +++++++++++++++++- > include/uapi/linux/intel_sdsi.h | 81 +++++++ > 4 files changed, 292 insertions(+), 1 deletion(-) > create mode 100644 include/uapi/linux/intel_sdsi.h > > diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst > index c472423412bf..20dcc2dbcaf6 100644 > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst > @@ -382,6 +382,7 @@ Code Seq# Include File Comments > <mailto:mathieu.desnoyers@xxxxxxxxxxxx> > 0xF8 all arch/x86/include/uapi/asm/amd_hsmp.h AMD HSMP EPYC system management interface driver > <mailto:nchatrad@xxxxxxx> > +0xFC all linux/intel_sdsi.h > 0xFD all linux/dm-ioctl.h > 0xFE all linux/isst_if.h > ==== ===== ======================================================= ================================================================ > diff --git a/MAINTAINERS b/MAINTAINERS > index 846187625552..060bd3358cec 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11165,6 +11165,7 @@ INTEL SDSI DRIVER > M: David E. Box <david.e.box@xxxxxxxxxxxxxxx> > S: Supported > F: drivers/platform/x86/intel/sdsi.c > +F: include/uapi/linux/intel_sdsi.h > F: tools/arch/x86/intel_sdsi/ > F: tools/testing/selftests/drivers/sdsi/ > > diff --git a/drivers/platform/x86/intel/sdsi.c b/drivers/platform/x86/intel/sdsi.c > index 277e4f4b20ac..686dd9e4e026 100644 > --- a/drivers/platform/x86/intel/sdsi.c > +++ b/drivers/platform/x86/intel/sdsi.c > @@ -11,9 +11,12 @@ > #include <linux/auxiliary_bus.h> > #include <linux/bits.h> > #include <linux/bitfield.h> > +#include <linux/cleanup.h> > #include <linux/device.h> > #include <linux/iopoll.h> > +#include <linux/intel_sdsi.h> > #include <linux/kernel.h> > +#include <linux/miscdevice.h> > #include <linux/module.h> > #include <linux/overflow.h> > #include <linux/pci.h> > @@ -42,6 +45,7 @@ > > #define SDSI_ENABLED_FEATURES_OFFSET 16 > #define SDSI_FEATURE_SDSI BIT(3) > +#define SDSI_FEATURE_ATTESTATION BIT(12) > #define SDSI_FEATURE_METERING BIT(26) > > #define SDSI_SOCKET_ID_OFFSET 64 > @@ -91,6 +95,7 @@ enum sdsi_command { > SDSI_CMD_PROVISION_CAP = 0x0008, > SDSI_CMD_READ_STATE = 0x0010, > SDSI_CMD_READ_METER = 0x0014, > + SDSI_CMD_ATTESTATION = 0x1012, > }; > > struct sdsi_mbox_info { > @@ -109,12 +114,14 @@ struct disc_table { > struct sdsi_priv { > struct mutex mb_lock; /* Mailbox access lock */ > struct device *dev; > + struct miscdevice miscdev; > void __iomem *control_addr; > void __iomem *mbox_addr; > void __iomem *regs_addr; > int control_size; > int maibox_size; > int registers_size; > + int id; > u32 guid; > u32 features; > }; > @@ -582,6 +589,97 @@ static const struct attribute_group sdsi_group = { > }; > __ATTRIBUTE_GROUPS(sdsi); > > +/* > + * SPDM transport > + * Returns size of the response message or an error code on failure. > + */ > +static int sdsi_spdm_exchange(void *private, const void *request, > + size_t request_sz, void *response, > + size_t response_sz) > +{ > + struct sdsi_priv *priv = private; > + struct sdsi_mbox_info info = {}; > + size_t spdm_msg_size, size; > + int ret; > + > + /* > + * For the attestation command, the mailbox write size is the sum of: > + * Size of the SPDM request payload, padded for qword alignment > + * 8 bytes for the mailbox command > + * 8 bytes for the actual (non-padded) size of the SPDM request > + */ > + if (request_sz > SDSI_SIZE_WRITE_MSG - 2 * sizeof(u64)) > + return -EOVERFLOW; > + > + info.size = round_up(request_sz, sizeof(u64)) + 2 * sizeof(u64); > + > + u64 *payload __free(kfree) = kzalloc(info.size, GFP_KERNEL); > + if (!payload) > + return -ENOMEM; > + > + memcpy(payload, request, request_sz); > + > + /* The non-padded SPDM payload size is the 2nd-to-last qword */ > + payload[(info.size / sizeof(u64)) - 2] = request_sz; > + > + /* Attestation mailbox command is the last qword of payload buffer */ > + payload[(info.size / sizeof(u64)) - 1] = SDSI_CMD_ATTESTATION; > + > + info.payload = payload; > + info.buffer = response; > + > + ret = mutex_lock_interruptible(&priv->mb_lock); > + if (ret) > + return ret; > + ret = sdsi_mbox_write(priv, &info, &size); > + mutex_unlock(&priv->mb_lock); > + > + if (ret < 0) > + return ret; > + > + /* > + * The read size is the sum of: > + * Size of the SPDM response payload, padded for qword alignment > + * 8 bytes for the actual (non-padded) size of the SPDM payload > + */ > + > + if (size < sizeof(u64)) { > + dev_err(priv->dev, > + "Attestation error: Mailbox reply size, %ld, too small\n", > + size); For size_t, %zu is the correct printf format. There are more of these below but I won't mark them explicitly. > + return -EPROTO; > + } > + > + if (!IS_ALIGNED(size, sizeof(u64))) { > + dev_err(priv->dev, > + "Attestation error: Mailbox reply size, %ld, is not aligned\n", > + size); > + return -EPROTO; > + } > + > + /* > + * Get the SPDM response size from the last QWORD and check it fits > + * with no more than 7 bytes of padding > + */ > + spdm_msg_size = ((u64 *)info.buffer)[(size - sizeof(u64)) / sizeof(u64)]; > + if (!in_range(size - spdm_msg_size - sizeof(u64), 0, 8)) { > + dev_err(priv->dev, > + "Attestation error: Invalid SPDM response size, %ld\n", > + spdm_msg_size); > + return -EPROTO; > + } > + > + if (spdm_msg_size > response_sz || spdm_msg_size < SPDM_HEADER_SIZE) { > + dev_err(priv->dev, "Attestation error: Expected response size %ld, got %ld\n", > + response_sz, spdm_msg_size); > + return -EOVERFLOW; > + } > + > + memcpy(response, info.buffer, spdm_msg_size); > + > + return spdm_msg_size; > +} > + > static int sdsi_get_layout(struct sdsi_priv *priv, struct disc_table *table) > { > switch (table->guid) { > @@ -649,6 +747,92 @@ static int sdsi_map_mbox_registers(struct sdsi_priv *priv, struct pci_dev *paren > return 0; > } > > +#define SDSI_SPDM_DRIVER_VERSION 1 > + > +static int sdsi_spdm_get_info(struct sdsi_priv *priv, > + struct sdsi_spdm_info __user *argp) > +{ > + struct sdsi_spdm_info info; > + > + info.driver_version = SDSI_SPDM_DRIVER_VERSION; > + info.api_version = priv->guid; > + info.dev_no = priv->id; > + info.max_request_size = SDSI_SIZE_WRITE_MSG - 2 * sizeof(u64); > + info.max_response_size = SDSI_SIZE_READ_MSG - sizeof(u64); > + > + if (copy_to_user(argp, &info, sizeof(info))) > + return -EFAULT; > + > + return 0; > +} > + > +static int sdsi_spdm_do_command(struct sdsi_priv *priv, > + struct sdsi_spdm_command __user *argp) > +{ > + u32 req_size, rsp_size; > + > + if (get_user(req_size, &argp->size)) > + return -EFAULT; > + > + if (req_size < 4 || req_size > sizeof(struct sdsi_spdm_message)) > + return -EINVAL; > + > + struct sdsi_spdm_message *request __free(kfree) = > + kmalloc(req_size, GFP_KERNEL); > + if (!request) > + return -ENOMEM; > + > + struct sdsi_spdm_command *response __free(kfree) = > + kmalloc(SDSI_SIZE_READ_MSG, GFP_KERNEL); > + if (!response) > + return -ENOMEM; > + > + if (copy_from_user(request, &argp->message, req_size)) > + return -EFAULT; > + > + rsp_size = sdsi_spdm_exchange(priv, request, req_size, response, > + SDSI_SIZE_READ_MSG); > + if (rsp_size < 0) > + return rsp_size; > + > + if (put_user(rsp_size, &argp->size)) > + return -EFAULT; > + > + if (copy_to_user(&argp->message, response, rsp_size)) > + return -EFAULT; > + > + return 0; > +} > + > +static long sdsi_spdm_ioctl(struct file *file, unsigned int cmd, > + unsigned long arg) > +{ > + struct sdsi_priv *priv; > + long ret = -ENOTTY; > + > + priv = container_of(file->private_data, struct sdsi_priv, miscdev); > + > + switch (cmd) { > + case SDSI_IF_SPDM_INFO: > + ret = sdsi_spdm_get_info(priv, > + (struct sdsi_spdm_info __user *)arg); > + break; > + case SDSI_IF_SPDM_COMMAND: > + ret = sdsi_spdm_do_command(priv, > + (struct sdsi_spdm_command __user *)arg); You can return directly. > + break; > + default: > + break; > + } > + > + return ret; return -ENOTTY; and remove the ret variable entirely. -- i.
