[v18,065/121] KVM: TDX: Finalize VM initialization

Commit Message

Isaku Yamahata Jan. 22, 2024, 11:53 p.m. UTC

From: Isaku Yamahata <[e-mail]>

To protect the initial contents of the guest TD, the TDX module measures
the guest TD during the build process as SHA-384 measurement.  The
measurement of the guest TD contents needs to be completed to make the
guest TD ready to run.

Add a new subcommand, KVM_TDX_FINALIZE_VM, for VM-scoped
KVM_MEMORY_ENCRYPT_OP to finalize the measurement and mark the TDX VM ready
to run.

Signed-off-by: Isaku Yamahata <[e-mail]>

---
v18:
- Remove the change of tools/arch/x86/include/uapi/asm/kvm.h.

v14 -> v15:
- removed unconditional tdx_track() by tdx_flush_tlb_current() that
  does tdx_track().
---
 arch/x86/include/uapi/asm/kvm.h |  1 +
 arch/x86/kvm/vmx/tdx.c          | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)

Patch

diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 9fda7c90b7b5..f2a37b479f26 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -573,6 +573,7 @@  enum kvm_tdx_cmd_id {
 	KVM_TDX_INIT_VM,
 	KVM_TDX_INIT_VCPU,
 	KVM_TDX_INIT_MEM_REGION,
+	KVM_TDX_FINALIZE_VM,
 
 	KVM_TDX_CMD_NR_MAX,
 };
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 1a5a91b99de9..faa04d8922b6 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1473,6 +1473,24 @@  static int tdx_init_mem_region(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
 	return ret;
 }
 
+static int tdx_td_finalizemr(struct kvm *kvm)
+{
+	struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+	u64 err;
+
+	if (!is_hkid_assigned(kvm_tdx) || is_td_finalized(kvm_tdx))
+		return -EINVAL;
+
+	err = tdh_mr_finalize(kvm_tdx->tdr_pa);
+	if (WARN_ON_ONCE(err)) {
+		pr_tdx_error(TDH_MR_FINALIZE, err, NULL);
+		return -EIO;
+	}
+
+	kvm_tdx->finalized = true;
+	return 0;
+}
+
 int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 {
 	struct kvm_tdx_cmd tdx_cmd;
@@ -1495,6 +1513,9 @@  int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 	case KVM_TDX_INIT_MEM_REGION:
 		r = tdx_init_mem_region(kvm, &tdx_cmd);
 		break;
+	case KVM_TDX_FINALIZE_VM:
+		r = tdx_td_finalizemr(kvm);
+		break;
 	default:
 		r = -EINVAL;
 		goto out;