Re: [PATCH v2 0/3] TDX attestation support and GHCI fixup

[Xiaoyao Li]

On 6/20/2025 2:01 AM, Paolo Bonzini wrote:
> This is a refresh of Binbin's patches with a change to the userspace
> API.  I am consolidating everything into a single KVM_EXIT_TDX and
> adding to the contract that userspace is free to ignore it *except*
> for having to reenter the guest with KVM_RUN.
>
> If in the future this does not work, it should be possible to introduce
> an opt-in interface.  Hopefully that will not be necessary.

For <GetTdVmCallInfo> exit, I think KVM still needs to report which 
TDVMCALL leaf will exit to userspace, to differentiate between different 
KVMs.

But it's not a must for current <GetQuote> since it exits to userspace 
from day 0. So that we can leave the report interface until KVM needs to 
support user exit of another TDVMCALL leaf.

> Paolo
>
> Binbin Wu (3):
>    KVM: TDX: Add new TDVMCALL status code for unsupported subfuncs
>    KVM: TDX: Handle TDG.VP.VMCALL<GetQuote>
>    KVM: TDX: Exit to userspace for GetTdVmCallInfo
>
>   Documentation/virt/kvm/api.rst    | 62 ++++++++++++++++++++++++-
>   arch/x86/include/asm/shared/tdx.h |  1 +
>   arch/x86/kvm/vmx/tdx.c            | 77 ++++++++++++++++++++++++++++---
>   include/uapi/linux/kvm.h          | 22 +++++++++
>   4 files changed, 154 insertions(+), 8 deletions(-)