diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst b/Documentation/virt/kvm/amd-memory-encryption.rst index 34ce2d1fcb89..db5c3fb2bab5 100644 --- a/Documentation/virt/kvm/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/amd-memory-encryption.rst @@ -290,6 +290,36 @@ Returns: 0 on success, -negative on error __u32 len; }; +11. KVM_SEV_SEND_START +---------------------- + +The KVM_SEV_SEND_START command can be used by the hypervisor to create an +outgoing guest encryption context. + +If session_len is zero on entry, the length of the guest session information is +written to session_len and all other fields are not used. + +Parameters (in): struct kvm_sev_send_start + +Returns: 0 on success, -negative on error + +:: + struct kvm_sev_send_start { + __u32 policy; /* guest policy */ + + __u64 pdh_cert_uaddr; /* platform Diffie-Hellman certificate */ + __u32 pdh_cert_len; + + __u64 plat_certs_uaddr; /* platform certificate chain */ + __u32 plat_certs_len; + + __u64 amd_certs_uaddr; /* AMD certificate */ + __u32 amd_certs_len; + + __u64 session_uaddr; /* Guest session information */ + __u32 session_len; + }; + References ========== diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 4bf79dbc3eeb..9f5312956d5e 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1111,6 +1111,131 @@ e_free: return ret; } +/* Userspace wants to query session length. */ +static int +__sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd *argp, + struct kvm_sev_send_start *params) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct sev_data_send_start *data; + int ret; + + data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT); + if (data == NULL) + return -ENOMEM; + + data->handle = sev->handle; + ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, data, &argp->error); + if (ret < 0) + goto out; + + params->session_len = data->session_len; + if (copy_to_user((void __user *)(uintptr_t)argp->data, params, + sizeof(struct kvm_sev_send_start))) + ret = -EFAULT; + +out: + kfree(data); + return ret; +} + +static int sev_send_start(struct kvm *kvm, struct kvm_sev_cmd *argp) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + struct sev_data_send_start *data; + struct kvm_sev_send_start params; + void *amd_certs, *session_data; + void *pdh_cert, *plat_certs; + int ret; + + if (!sev_guest(kvm)) + return -ENOTTY; + + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, + sizeof(struct kvm_sev_send_start))) + return -EFAULT; + + /* if session_len is zero, userspace wants to query the session length */ + if (!params.session_len) + return __sev_send_start_query_session_length(kvm, argp, + ¶ms); + + /* some sanity checks */ + if (!params.pdh_cert_uaddr || !params.pdh_cert_len || + !params.session_uaddr || params.session_len > SEV_FW_BLOB_MAX_SIZE) + return -EINVAL; + + /* allocate the memory to hold the session data blob */ + session_data = kmalloc(params.session_len, GFP_KERNEL_ACCOUNT); + if (!session_data) + return -ENOMEM; + + /* copy the certificate blobs from userspace */ + pdh_cert = psp_copy_user_blob(params.pdh_cert_uaddr, + params.pdh_cert_len); + if (IS_ERR(pdh_cert)) { + ret = PTR_ERR(pdh_cert); + goto e_free_session; + } + + plat_certs = psp_copy_user_blob(params.plat_certs_uaddr, + params.plat_certs_len); + if (IS_ERR(plat_certs)) { + ret = PTR_ERR(plat_certs); + goto e_free_pdh; + } + + amd_certs = psp_copy_user_blob(params.amd_certs_uaddr, + params.amd_certs_len); + if (IS_ERR(amd_certs)) { + ret = PTR_ERR(amd_certs); + goto e_free_plat_cert; + } + + data = kzalloc(sizeof(*data), GFP_KERNEL_ACCOUNT); + if (data == NULL) { + ret = -ENOMEM; + goto e_free_amd_cert; + } + + /* populate the FW SEND_START field with system physical address */ + data->pdh_cert_address = __psp_pa(pdh_cert); + data->pdh_cert_len = params.pdh_cert_len; + data->plat_certs_address = __psp_pa(plat_certs); + data->plat_certs_len = params.plat_certs_len; + data->amd_certs_address = __psp_pa(amd_certs); + data->amd_certs_len = params.amd_certs_len; + data->session_address = __psp_pa(session_data); + data->session_len = params.session_len; + data->handle = sev->handle; + + ret = sev_issue_cmd(kvm, SEV_CMD_SEND_START, data, &argp->error); + + if (!ret && copy_to_user((void __user *)(uintptr_t)params.session_uaddr, + session_data, params.session_len)) { + ret = -EFAULT; + goto e_free; + } + + params.policy = data->policy; + params.session_len = data->session_len; + if (copy_to_user((void __user *)(uintptr_t)argp->data, ¶ms, + sizeof(struct kvm_sev_send_start))) + ret = -EFAULT; + +e_free: + kfree(data); +e_free_amd_cert: + kfree(amd_certs); +e_free_plat_cert: + kfree(plat_certs); +e_free_pdh: + kfree(pdh_cert); +e_free_session: + kfree(session_data); + return ret; +} + int svm_mem_enc_op(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; @@ -1173,6 +1298,9 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp) case KVM_SEV_GET_ATTESTATION_REPORT: r = sev_get_attestation_report(kvm, &sev_cmd); break; + case KVM_SEV_SEND_START: + r = sev_send_start(kvm, &sev_cmd); + break; default: r = -EINVAL; goto out; diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h index b801ead1e2bb..73da511b9423 100644 --- a/include/linux/psp-sev.h +++ b/include/linux/psp-sev.h @@ -326,11 +326,11 @@ struct sev_data_send_start { u64 pdh_cert_address; /* In */ u32 pdh_cert_len; /* In */ u32 reserved1; - u64 plat_cert_address; /* In */ - u32 plat_cert_len; /* In */ + u64 plat_certs_address; /* In */ + u32 plat_certs_len; /* In */ u32 reserved2; - u64 amd_cert_address; /* In */ - u32 amd_cert_len; /* In */ + u64 amd_certs_address; /* In */ + u32 amd_certs_len; /* In */ u32 reserved3; u64 session_address; /* In */ u32 session_len; /* In/Out */ diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 37f0a329da6a..11b3e528d35d 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1732,6 +1732,18 @@ struct kvm_sev_attestation_report { __u32 len; }; +struct kvm_sev_send_start { + __u32 policy; + __u64 pdh_cert_uaddr; + __u32 pdh_cert_len; + __u64 plat_certs_uaddr; + __u32 plat_certs_len; + __u64 amd_certs_uaddr; + __u32 amd_certs_len; + __u64 session_uaddr; + __u32 session_len; +}; + #define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) #define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1) #define KVM_DEV_ASSIGN_MASK_INTX (1 << 2)