On 12/16/2024 8:54 AM, Binbin Wu wrote:
On 12/13/2024 4:57 PM, Xiaoyao Li wrote:
On 12/1/2024 11:53 AM, Binbin Wu wrote:
...
}
void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int
pgd_level)
@@ -1135,6 +1215,88 @@ int tdx_sept_remove_private_spte(struct kvm
*kvm, gfn_t gfn,
return tdx_sept_drop_private_spte(kvm, gfn, level, pfn);
}
+int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
+{
+ struct vcpu_tdx *tdx = to_tdx(vcpu);
+ u64 vp_enter_ret = tdx->vp_enter_ret;
+ union vmx_exit_reason exit_reason;
+
+ if (fastpath != EXIT_FASTPATH_NONE)
+ return 1;
+
+ /*
+ * Handle TDX SW errors, including TDX_SEAMCALL_UD,
TDX_SEAMCALL_GP and
+ * TDX_SEAMCALL_VMFAILINVALID.
+ */
+ if (unlikely((vp_enter_ret & TDX_SW_ERROR) == TDX_SW_ERROR)) {
+ KVM_BUG_ON(!kvm_rebooting, vcpu->kvm);
+ goto unhandled_exit;
+ }
+
+ /*
+ * Without off-TD debug enabled, failed_vmentry case must have
+ * TDX_NON_RECOVERABLE set.
+ */
This comment is confusing. I'm not sure why it is put here. Below code
does nothing with exit_reason.failed_vmentry.
Because when failed_vmentry occurs, vp_enter_ret will have
TDX_NON_RECOVERABLE set, so it will be handled below.
The words somehow is confusing, which to me is implying something like:
WARN_ON(!debug_td() && exit_reason.failed_vmentry &&
!(vp_enter_ret & TDX_NON_RECOVERABLE))
Besides, VMX returns KVM_EXIT_FAIL_ENTRY for vm-entry failure. So the
question is why TDX cannot do it same way?
+ if (unlikely(vp_enter_ret & (TDX_ERROR | TDX_NON_RECOVERABLE))) {
+ /* Triple fault is non-recoverable. */
+ if (unlikely(tdx_check_exit_reason(vcpu,
EXIT_REASON_TRIPLE_FAULT)))
+ return tdx_handle_triple_fault(vcpu);
+
+ kvm_pr_unimpl("TD vp_enter_ret 0x%llx, hkid 0x%x hkid pa
0x%llx\n",
+ vp_enter_ret, to_kvm_tdx(vcpu->kvm)->hkid,
+ set_hkid_to_hpa(0, to_kvm_tdx(vcpu->kvm)->hkid));
It indeed needs clarification for the need of "hkid" and "hkid pa".
Especially the "hkdi pa", which is the result of applying HKID of the
current TD to a physical address 0. I cannot think of any reason why
we need such info.
Yes, set_hkid_to_hpa(0, to_kvm_tdx(vcpu->kvm)->hkid) should be removed.
I didn't notice it.
don't forget to justify why HKID is useful here. To me, HKID can be
dropped as well.
Thanks!
+ goto unhandled_exit;
+ }
+
+ /* From now, the seamcall status should be TDX_SUCCESS. */
+ WARN_ON_ONCE((vp_enter_ret & TDX_SEAMCALL_STATUS_MASK) !=
TDX_SUCCESS);
Is there any case that TDX_SUCCESS with additional non-zero
information in the lower 32-bits? I thought TDX_SUCCESS is a whole 64-
bit status code.
TDX status code uses the upper 32-bits.
When the status code is TDX_SUCCESS and has a valid VMX exit reason, the
lower
32-bit is the VMX exit reason.
You can refer to the TDX module ABI spec or
interface_function_completion_status.json
from the intel-tdx-module-1.5-abi-table for details.
I see. (I asked a silly question that I even missed the normal Exit case)
