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Fri, 23 Oct 2026 02:13:45 +0000 Date: Fri, 23 Oct 2026 10:12:45 +0800 From: Yan Zhao To: "Edgecombe, Rick P" CC: "Du, Fan" , , "Li, Xiaoyao" , "Hansen, Dave" , "thomas.lendacky@amd.com" , "vbabka@suse.cz" , "tabba@google.com" , "david@kernel.org" , "kas@kernel.org" , "binbin.wu@linux.intel.com" , "seanjc@google.com" , "pbonzini@redhat.com" , "Peng, Chao P" , "ackerleytng@google.com" , "michael.roth@amd.com" , "nik.borisov@suse.com" , "linux-kernel@vger.kernel.org" , "sagis@google.com" , "Annapurve, Vishal" , "Chen, Farrah" , "Gao, Chao" , "francescolavra.fl@gmail.com" , "Miao, Jun" , "jgross@suse.com" , "pgonda@google.com" , "x86@kernel.org" Subject: Re: [PATCH v4 08/17] KVM: TDX: Adjust the topup count of DPAMT page pairs for splitting S-EPT Message-ID: Reply-To: Yan Zhao References: <25927de50b85816956e8989f402ff6ccfa8fa0ba.camel@intel.com> <55ccf641218c6553b2f43f4394b92c23bd8b5d98.camel@intel.com> <29790651d7a5d8727f956985823c17e3dfbdcc24.camel@intel.com> <97ad9dac09d945ab5b76ec8596a76f8fdf2bb6b6.camel@intel.com> Content-Type: text/plain; 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Instead of expanding the details in the comment, would it be better > > to put the explanation in the patch changelog? > > I think the detail that is missing is that DPAMT only needs one page pair per > 2MB aligned region. That info is encapsulated in arch/x86 side. So I think this > code needs a comment to cover that part. Makes sense. > That the 2MB page is 2MB aligned is not necessary. Can you propose something > else? What about /* * Only one DPAMT page pair is needed per 2MB aligned region. * +1 pair to account for mapping a new 4KB guest page or splitting a * 2MB guest page into 512 4KB pages. */ ? > > > > > /* > > >   * +1 pair to account for mapping a new 4KB guest page or splitting a > > >   * 2MB guest page. Since the resulting split 2MB page will be 2MB > > >   * aligned it will only end up needing one DPAMT page pair to cover all > > >   * 512 4KB pages. > > >   */ > >