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

From: isaku . yamahata
Date: Mon Jan 22 2024 - 19:10:40 EST


From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

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 <isaku.yamahata@xxxxxxxxx>

---
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(+)

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;
--
2.25.1