Re: [PATCH v3 3/4] KVM: TDX: Don't assume exit_reason[31:16] as all-0 in tdx_to_vmx_exit_reason()

[Xiaoyao Li <xiaoyao.li@intel.com>]

On 8/13/2026 8:14 AM, Sean Christopherson wrote:
> On Wed, Aug 12, 2026, Xiaoyao Li wrote:
>> On 8/12/2026 4:23 PM, sashiko-bot@kernel.org wrote:
>>>> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
>>> When the basic exit reason is set to TDX_INVALID_EXIT_REASON here, but upper
>>> bits like Bus Lock are preserved in exit_reason.full, does this break
>>> tdx_get_exit_info()?
>>>
>>> In tdx_get_exit_info(), it evaluates against the full 32-bit exit reason:
>>>
>>>       *reason = tdx->vt.exit_reason.full;
>>>       if (*reason != TDX_INVALID_EXIT_REASON) {
>>>           *info1 = vmx_get_exit_qual(vcpu);
>>>           ...
>>>
>>> Since TDX_INVALID_EXIT_REASON is the 16-bit 0xFFFF, this check will pass if
>>> any upper bits are set, even if the basic reason was marked invalid,
>>> incorrectly exposing meaningless hardware state.
>>
>> Oh, I should have called it out it's intentional to check the full 32 bits
>> Exit Reason instead of checking the lower 16 bits .basic field as what it
>> did in the v2.
> 
> Please wait for discussion to die down before sending new versions.  You sent
> this version literally the same day you responded to some of my comments on v2.
> Now the discussion is spread across different mail threads and I'm having to
> piece the converation together.
> 
> In short, spamming versions makes it harder to review, and thus slows the process
> down; it doesn't speed things up.

My apologies for this.