From f5db8841ebe59dbdf07fda797c88ccb51e0c893d Mon Sep 17 00:00:00 2001 From: Brijesh Singh Date: Thu, 25 Jan 2024 22:11:23 -0600 Subject: crypto: ccp: Add the SNP_PLATFORM_STATUS command This command is used to query the SNP platform status. See the SEV-SNP spec for more details. Signed-off-by: Brijesh Singh Signed-off-by: Ashish Kalra Signed-off-by: Michael Roth Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20240126041126.1927228-24-michael.roth@amd.com --- Documentation/virt/coco/sev-guest.rst | 27 ++++++++++++++++++ drivers/crypto/ccp/sev-dev.c | 52 +++++++++++++++++++++++++++++++++++ include/uapi/linux/psp-sev.h | 1 + 3 files changed, 80 insertions(+) diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst index 68b0d2363af8..6d3d5d336e5f 100644 --- a/Documentation/virt/coco/sev-guest.rst +++ b/Documentation/virt/coco/sev-guest.rst @@ -67,6 +67,22 @@ counter (e.g. counter overflow), then -EIO will be returned. }; }; +The host ioctls are issued to a file descriptor of the /dev/sev device. +The ioctl accepts the command ID/input structure documented below. + +:: + struct sev_issue_cmd { + /* Command ID */ + __u32 cmd; + + /* Command request structure */ + __u64 data; + + /* Firmware error code on failure (see psp-sev.h) */ + __u32 error; + }; + + 2.1 SNP_GET_REPORT ------------------ @@ -124,6 +140,17 @@ be updated with the expected value. See GHCB specification for further detail on how to parse the certificate blob. +2.4 SNP_PLATFORM_STATUS +----------------------- +:Technology: sev-snp +:Type: hypervisor ioctl cmd +:Parameters (out): struct sev_user_data_snp_status +:Returns (out): 0 on success, -negative on error + +The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The +status includes API major, minor version and more. See the SEV-SNP +specification for further details. + 3. SEV-SNP CPUID Enforcement ============================ diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 504a2216bded..ae02efe2736c 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -1941,6 +1941,55 @@ e_free_pdh: return ret; } +static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp) +{ + struct sev_device *sev = psp_master->sev_data; + struct sev_data_snp_addr buf; + struct page *status_page; + void *data; + int ret; + + if (!sev->snp_initialized || !argp->data) + return -EINVAL; + + status_page = alloc_page(GFP_KERNEL_ACCOUNT); + if (!status_page) + return -ENOMEM; + + data = page_address(status_page); + + /* + * Firmware expects status page to be in firmware-owned state, otherwise + * it will report firmware error code INVALID_PAGE_STATE (0x1A). + */ + if (rmp_mark_pages_firmware(__pa(data), 1, true)) { + ret = -EFAULT; + goto cleanup; + } + + buf.address = __psp_pa(data); + ret = __sev_do_cmd_locked(SEV_CMD_SNP_PLATFORM_STATUS, &buf, &argp->error); + + /* + * Status page will be transitioned to Reclaim state upon success, or + * left in Firmware state in failure. Use snp_reclaim_pages() to + * transition either case back to Hypervisor-owned state. + */ + if (snp_reclaim_pages(__pa(data), 1, true)) + return -EFAULT; + + if (ret) + goto cleanup; + + if (copy_to_user((void __user *)argp->data, data, + sizeof(struct sev_user_data_snp_status))) + ret = -EFAULT; + +cleanup: + __free_pages(status_page, 0); + return ret; +} + static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) { void __user *argp = (void __user *)arg; @@ -1992,6 +2041,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) case SEV_GET_ID2: ret = sev_ioctl_do_get_id2(&input); break; + case SNP_PLATFORM_STATUS: + ret = sev_ioctl_do_snp_platform_status(&input); + break; default: ret = -EINVAL; goto out; diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h index 207e34217528..f1e2c55a92b4 100644 --- a/include/uapi/linux/psp-sev.h +++ b/include/uapi/linux/psp-sev.h @@ -28,6 +28,7 @@ enum { SEV_PEK_CERT_IMPORT, SEV_GET_ID, /* This command is deprecated, use SEV_GET_ID2 */ SEV_GET_ID2, + SNP_PLATFORM_STATUS, SEV_MAX, }; -- cgit v1.2.3