On 9/4/24 05:07, Rick Edgecombe wrote:
From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Add a new VM-scoped KVM_MEMORY_ENCRYPT_OP IOCTL subcommand,
KVM_TDX_FINALIZE_VM, to perform TD Measurement Finalization.
Documentation for the API is added in another patch:
"Documentation/virt/kvm: Document on Trust Domain Extensions(TDX)"
For the purpose of attestation, a measurement must be made of the TDX VM
initial state. This is referred to as TD Measurement Finalization, and
uses SEAMCALL TDH.MR.FINALIZE, after which:
1. The VMM adding TD private pages with arbitrary content is no longer
allowed
2. The TDX VM is runnable
Co-developed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
---
TDX MMU part 2 v1:
- Added premapped check.
- Update for the wrapper functions for SEAMCALLs. (Sean)
- Add check if nr_premapped is zero. If not, return error.
- Use KVM_BUG_ON() in tdx_td_finalizer() for consistency.
- Change tdx_td_finalizemr() to take struct kvm_tdx_cmd *cmd and return error
(Adrian)
- Handle TDX_OPERAND_BUSY case (Adrian)
- Updates from seamcall overhaul (Kai)
- Rename error->hw_error
v18:
- Remove the change of tools/arch/x86/include/uapi/asm/kvm.h.
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 | 28 ++++++++++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 789d1d821b4f..0b4827e39458 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -932,6 +932,7 @@ enum kvm_tdx_cmd_id {
KVM_TDX_INIT_VM,
KVM_TDX_INIT_VCPU,
KVM_TDX_INIT_MEM_REGION,
+ KVM_TDX_FINALIZE_VM,
KVM_TDX_GET_CPUID,
KVM_TDX_CMD_NR_MAX,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 796d1a495a66..3083a66bb895 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1257,6 +1257,31 @@ void tdx_flush_tlb_current(struct kvm_vcpu *vcpu)
ept_sync_global();
}
+static int tdx_td_finalizemr(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
+{
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+
+ if (!is_hkid_assigned(kvm_tdx) || is_td_finalized(kvm_tdx))
+ return -EINVAL;
+ /*
+ * Pages are pending for KVM_TDX_INIT_MEM_REGION to issue
+ * TDH.MEM.PAGE.ADD().
+ */
+ if (atomic64_read(&kvm_tdx->nr_premapped))
+ return -EINVAL;
I suggest moving all of patch 16, plus the
+ WARN_ON_ONCE(!atomic64_read(&kvm_tdx->nr_premapped));
+ atomic64_dec(&kvm_tdx->nr_premapped);
lines of patch 19, into this patch.
+ cmd->hw_error = tdh_mr_finalize(kvm_tdx);
+ if ((cmd->hw_error & TDX_SEAMCALL_STATUS_MASK) == TDX_OPERAND_BUSY)
+ return -EAGAIN;
+ if (KVM_BUG_ON(cmd->hw_error, kvm)) {
+ pr_tdx_error(TDH_MR_FINALIZE, cmd->hw_error);
+ return -EIO;
+ }
+
+ kvm_tdx->finalized = true;
+ return 0;
This should also set pre_fault_allowed to true.
Paolo
