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Date: Wed, 20 Mar 2024 13:20:40 -0700
From: Isaku Yamahata <isaku.yamahata@intel.com>
To: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: "Yamahata, Isaku" <isaku.yamahata@intel.com>,
	"Zhang, Tina" <tina.zhang@intel.com>,
	"isaku.yamahata@linux.intel.com" <isaku.yamahata@linux.intel.com>,
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	"Huang, Kai" <kai.huang@intel.com>,
	"sean.j.christopherson@intel.com" <sean.j.christopherson@intel.com>,
	"Chen, Bo2" <chen.bo@intel.com>,
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	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Yuan, Hang" <hang.yuan@intel.com>,
	"Aktas, Erdem" <erdemaktas@google.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
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	"Yao, Yuan" <yuan.yao@intel.com>,
	"isaku.yamahata@gmail.com" <isaku.yamahata@gmail.com>,
	"binbin.wu@linux.intel.com" <binbin.wu@linux.intel.com>
Subject: Re: [PATCH v19 029/130] KVM: TDX: Add C wrapper functions for
 SEAMCALLs to the TDX module
Message-ID: <20240320202040.GH1994522@ls.amr.corp.intel.com>
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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>