Re: [PATCH 03/25] KVM: TDX: Add TDX "architectural" error codes

Binbin Wu
2024-08-13T06:08:47Z

On 8/13/2024 6:47 AM, Rick Edgecombe wrote:
> From: Sean Christopherson <sean.j.christopherson@intel.com>
>
> Add error codes for the TDX SEAMCALLs both for TDX VMM side for TDH
> SEAMCALL and TDX guest side for TDG.VP.VMCALL. KVM issues the TDX
> SEAMCALLs and checks its error code. KVM handles hypercall from the TDX
> guest and may return an error. So error code for the TDX guest is also
> needed.
>
> TDX SEAMCALL uses bits 31:0 to return more information, so these error
> codes will only exactly match RAX[63:32]. Error codes for TDG.VP.VMCALL is
> defined by TDX Guest-Host-Communication interface spec.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Reviewed-by: Yuan Yao <yuan.yao@intel.com>
> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
> ---
> v19:
> - Drop TDX_EPT_WALK_FAILED, TDX_EPT_ENTRY_NOT_FREE
> - Rename TDG_VP_VMCALL_ => TDVMCALL_ to match the existing code
> - Move TDVMCALL error codes to shared/tdx.h
> - Added TDX_OPERAND_ID_TDR
> - Fix bisectability issues in headers (Kai)
> ---
> arch/x86/include/asm/shared/tdx.h | 6 ++++++
> arch/x86/kvm/vmx/tdx.h | 1 +
> arch/x86/kvm/vmx/tdx_errno.h | 36 +++++++++++++++++++++++++++++++
> 3 files changed, 43 insertions(+)
> create mode 100644 arch/x86/kvm/vmx/tdx_errno.h
>
> diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h
> index fdfd41511b02..6ebbf8ee80b3 100644
> --- a/arch/x86/include/asm/shared/tdx.h
> +++ b/arch/x86/include/asm/shared/tdx.h
> @@ -28,6 +28,12 @@
>
> #define TDVMCALL_STATUS_RETRY 1
>
> +/*
> + * TDG.VP.VMCALL Status Codes (returned in R10)
> + */
> +#define TDVMCALL_SUCCESS 0x0000000000000000ULL
> +#define TDVMCALL_INVALID_OPERAND 0x8000000000000000ULL
> +
TDX guest code has already defined/uses "TDVMCALL_STATUS_RETRY", which
is one
of the TDG.VP.VMCALL Status Codes.

IMHO, the style of the macros should be unified.
How about using TDVMALL_STATUS_* for TDG.VP.VMCALL Status Codes?

+/*
+ * TDG.VP.VMCALL Status Codes (returned in R10)
+ */
+#define TDVMCALL_STATUS_SUCCESS 0x0000000000000000ULL
-#define TDVMCALL_STATUS_RETRY                  1
+#define TDVMCALL_STATUS_RETRY 0x0000000000000001ULL
+#define TDVMCALL_STATUS_INVALID_OPERAND 0x8000000000000000ULL …