Re: [PATCH v1] virt: tdx-guest: Add Quote generation support using TSM_REPORTS

[Huang, Kai]

On Sun, 2023-09-10 at 17:10 -0700, Kuppuswamy Sathyanarayanan wrote:
> 
> On 9/8/2023 9:19 AM, Dan Williams wrote:
> > > > Changes since previous version:
> > > > * Used ConfigFS interface instead of IOCTL interface.
> > > > * Used polling model for Quote generation and dropped the event notification IRQ support.
> > > Can you elaborate why the notification IRQ is dropped?
> > Because it was a pile of hacks and non-idiomatic complexity. It can come
> > back when / if driver code can treat it like a typical interrupt.
> 
> Currently, the VMM assumes that the vCPU that executes the TDG.VP.VMCALL
> <SetupEventNotifyInterrupt> hypercall as the target vCPU for event
> notification IRQ. To satisfy this assumption, the guest driver that uses
> this hypercall/IRQ had to include CPU/IRQ affinity related code changes. This
> adds unnecessary complication to the guest driver code without any real
> ARCH need or benefit. So we want to modify the GHCI ABI to let TD guest pass
> the target CPU as an argument. With this change, we can hide the IRQ related
> configuration in the IRQ chip code and let the guest driver treat the
> event notification IRQ as a regular interrupt.
> 

Sorry I missed some internal discussion.  Please feel free to ignore my
comments.