diff options
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index fdf3ba7dda07..4288e9eebe05 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -3379,6 +3379,7 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm) goto vmgexit_err; break; case SVM_VMGEXIT_GUEST_REQUEST: + case SVM_VMGEXIT_EXT_GUEST_REQUEST: if (!sev_snp_guest(vcpu->kvm) || !PAGE_ALIGNED(control->exit_info_1) || !PAGE_ALIGNED(control->exit_info_2) || @@ -4048,6 +4049,58 @@ out_unlock: return ret; } +static int snp_handle_ext_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_gpa) +{ + struct kvm *kvm = svm->vcpu.kvm; + u8 msg_type; + + if (!sev_snp_guest(kvm)) + return -EINVAL; + + if (kvm_read_guest(kvm, req_gpa + offsetof(struct snp_guest_msg_hdr, msg_type), + &msg_type, 1)) + return -EIO; + + /* + * As per GHCB spec, requests of type MSG_REPORT_REQ also allow for + * additional certificate data to be provided alongside the attestation + * report via the guest-provided data pages indicated by RAX/RBX. The + * certificate data is optional and requires additional KVM enablement + * to provide an interface for userspace to provide it, but KVM still + * needs to be able to handle extended guest requests either way. So + * provide a stub implementation that will always return an empty + * certificate table in the guest-provided data pages. + */ + if (msg_type == SNP_MSG_REPORT_REQ) { + struct kvm_vcpu *vcpu = &svm->vcpu; + u64 data_npages; + gpa_t data_gpa; + + if (!kvm_ghcb_rax_is_valid(svm) || !kvm_ghcb_rbx_is_valid(svm)) + goto request_invalid; + + data_gpa = vcpu->arch.regs[VCPU_REGS_RAX]; + data_npages = vcpu->arch.regs[VCPU_REGS_RBX]; + + if (!PAGE_ALIGNED(data_gpa)) + goto request_invalid; + + /* + * As per GHCB spec (see "SNP Extended Guest Request"), the + * certificate table is terminated by 24-bytes of zeroes. + */ + if (data_npages && kvm_clear_guest(kvm, data_gpa, 24)) + return -EIO; + } + + return snp_handle_guest_req(svm, req_gpa, resp_gpa); + +request_invalid: + ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2); + ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT); + return 1; /* resume guest */ +} + static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) { struct vmcb_control_area *control = &svm->vmcb->control; @@ -4325,6 +4378,9 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) case SVM_VMGEXIT_GUEST_REQUEST: ret = snp_handle_guest_req(svm, control->exit_info_1, control->exit_info_2); break; + case SVM_VMGEXIT_EXT_GUEST_REQUEST: + ret = snp_handle_ext_guest_req(svm, control->exit_info_1, control->exit_info_2); + break; case SVM_VMGEXIT_UNSUPPORTED_EVENT: vcpu_unimpl(vcpu, "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n", |