Re: [PATCH v19 029/130] KVM: TDX: Add C wrapper functions for SEAMCALLs to the TDX module

Isaku Yamahata
2024-03-20T20:20:53Z

On Tue, Mar 19, 2024 at 10:41:09PM -0700,
Isaku Yamahata <isaku.yamahata@intel.com> wrote:

> On Wed, Mar 20, 2024 at 12:11:17AM +0000,
> "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> wrote:
>
> > On Tue, 2024-03-19 at 17:09 -0700, Isaku Yamahata wrote:
> > > > The helper abstracts setting the arguments into the proper
> > > > registers
> > > > fields passed in, but doesn't abstract pulling the result out from
> > > > the
> > > > register fields. Then the caller has to manually extract them in
> > > > this
> > > > verbose way. Why not have the helper do both?
> > >
> > > Yes. Let me update those arguments.
> >
> > What were you thinking exactly, like?
> >
> > tdh_mem_sept_add(kvm_tdx, gpa, tdx_level, hpa, &entry, &level_state);
> >
> > And for the other helpers?
>
> I have the following four helpers. Other helpers will have no out argument.
>
> tdh_mem_sept_add(kvm_tdx, gpa, tdx_level, hpa, &entry, &level_state);
> tdh_mem_page_aug(kvm_tdx, gpa, hpa, &entry, &level_state);
> tdh_mem_page_remove(kvm_tdx, gpa, tdx_level, &entry, &level_state);
> tdh_mem_range_block(kvm_tdx, gpa, tdx_level, &entry, &level_state);

By updating the code, I found that tdh_mem_range_block() doesn't need out
variables. and tdh_vp_rd() needs output.
tdh_mem_range_block() doesn't need the out.

u64 tdh_vp_rd(struct vcpu_tdx *tdx, u64 field, u64 *value)
--
Isaku Yamahata <isaku.yamahata@intel.com>