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Message-ID: <e4a106ba016d790af60ed72492695ab2b905ede1.camel@intel.com>
Subject: Re: [PATCH v7 033/102] KVM: x86/mmu: Add address conversion
 functions for TDX shared bits
From:   Kai Huang <kai.huang@intel.com>
To:     Isaku Yamahata <isaku.yamahata@gmail.com>
Cc:     isaku.yamahata@intel.com, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
        Rick Edgecombe <rick.p.edgecombe@intel.com>
Date:   Wed, 13 Jul 2022 22:41:33 +1200
In-Reply-To: <20220713045225.GP1379820@ls.amr.corp.intel.com>
References: <cover.1656366337.git.isaku.yamahata@intel.com>
         <69f4b4942d5f17fad40a8d08556488b8e4b7954d.1656366338.git.isaku.yamahata@intel.com>
         <6cc36b662dffaf0aa2a2f389f073daa2d63a530b.camel@intel.com>
         <20220713045225.GP1379820@ls.amr.corp.intel.com>
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> >=20
> > And by applying this patch, nothing will prevent you to turn on INTEL_T=
DX_HOST
> > and KVM_INTEL, which also turns on KVM_MMU_PRIVATE.
> >=20
> > So 'kvm_arch::gfn_shared_mask' is guaranteed to be 0?  If not, can lega=
l
> > (shared) GFN for normal VM be potentially treated as private?
> >=20
> > If yes, perhaps explicitly call out in changelog so people don't need t=
o worry
> > about?
>=20
> struct kvm that includes struct kvm_arch is guaranteed to be zero.
>=20
> Here is the updated commit message.
>=20
> Author: Isaku Yamahata <isaku.yamahata@intel.com>
> Date:   Tue Jul 12 00:10:13 2022 -0700
>=20
>     KVM: x86/mmu: Add address conversion functions for TDX shared bit of =
GPA
>    =20
>     TDX repurposes one GPA bit (51 bit or 47 bit based on configuration) =
to
>     indicate the GPA is private(if cleared) or shared (if set) with VMM. =
 If
>     GPA.shared is set, GPA is converted existing conventional EPT pointed=
 by
>     EPTP.  If GPA.shared bit is cleared, GPA is converted by TDX module.
>     VMM has to issue SEAMCALLs to operate.

Sorry what does "GPA is converted ..." mean?


--=20
Thanks,
-Kai