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Message-ID: <a816c65d-1db2-9043-9e4c-bb0d3f318044@infradead.org>
Date:   Mon, 26 Jun 2023 14:44:51 -0700
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Subject: Re: [PATCH v2 3/6] KVM: Documentation: Add the missing description
 for ptep in kvm_mmu_page
Content-Language: en-US
To:     Mingwei Zhang <mizhang@google.com>,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>
Cc:     kvm@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, Kai Huang <kai.huang@intel.com>,
        Jim Mattson <jmattson@google.com>,
        David Matlack <dmatlack@google.com>,
        Ben Gardon <bgardon@google.com>, Xu Yilun <yilun.xu@intel.com>,
        Zhi Wang <zhi.wang.linux@gmail.com>
References: <20230626182016.4127366-1-mizhang@google.com>
 <20230626182016.4127366-4-mizhang@google.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <20230626182016.4127366-4-mizhang@google.com>
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On 6/26/23 11:20, Mingwei Zhang wrote:
> Add the missing description for ptep in kvm_mmu_page description. ptep is
> used when TDP MMU is enabled and it shares the storage with parent_ptes.
> Update the doc to help readers to get up-to-date info.
> 
> Signed-off-by: Mingwei Zhang <mizhang@google.com>
> ---
>  Documentation/virt/kvm/x86/mmu.rst | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/virt/kvm/x86/mmu.rst b/Documentation/virt/kvm/x86/mmu.rst
> index 4c9044b4dc6c..5cd6cd5e8926 100644
> --- a/Documentation/virt/kvm/x86/mmu.rst
> +++ b/Documentation/virt/kvm/x86/mmu.rst
> @@ -237,6 +237,11 @@ Shadow pages contain the following information:
>      parent_ptes points at this single spte, otherwise, there exists multiple
>      sptes pointing at this page and (parent_ptes & ~0x1) points at a data
>      structure with a list of parent sptes.
> +  ptep:
> +    The reverse mapping for the pte pointing at this page's spt. This field is
> +    used in replace of parent_ptes when TDP MMU is used. In TDP MMU, each

            in replacement of

> +    non-root shadow page will have one parent, while each root shadow page has
> +    no parent. Note that this field is a union with parent_ptes.
>    unsync:
>      If true, then the translations in this page may not match the guest's
>      translation.  This is equivalent to the state of the tlb when a pte is

-- 
~Randy