From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu Zhang Subject: Re: [PATCH v1 3/4] KVM: MMU: Add 5 level EPT & Shadow page table support. Date: Mon, 14 Aug 2017 22:55:57 +0800 Message-ID: <6b4d84f0-4159-19a4-3670-fb68ecc25753@linux.intel.com> References: <1502544906-1108-1-git-send-email-yu.c.zhang@linux.intel.com> <1502544906-1108-4-git-send-email-yu.c.zhang@linux.intel.com> <04271af0-e735-022b-fb22-4d39bf32b01b@redhat.com> <22052f76-f8b3-d18c-f21a-4cb367f90993@linux.intel.com> <2ab782d9-f1cc-f9d0-97d0-876a97f28fe2@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, rkrcmar@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, xiaoguangrong@tencent.com, joro@8bytes.org To: Paolo Bonzini , kvm@vger.kernel.org Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 8/14/2017 11:02 PM, Paolo Bonzini wrote: > On 14/08/2017 16:32, Yu Zhang wrote: >> >> On 8/14/2017 10:13 PM, Paolo Bonzini wrote: >>> On 14/08/2017 13:37, Yu Zhang wrote: >>>> Thanks a lot for your comments, Paolo. :-) >>>> >>>> >>>> On 8/14/2017 3:31 PM, Paolo Bonzini wrote: >>>>> On 12/08/2017 15:35, Yu Zhang wrote: >>>>>> struct rsvd_bits_validate { >>>>>> - u64 rsvd_bits_mask[2][4]; >>>>>> + u64 rsvd_bits_mask[2][5]; >>>>>> u64 bad_mt_xwr; >>>>>> }; >>>>> Can you change this 4 to PT64_ROOT_MAX_LEVEL in patch 2? >>>> Well, I had tried, but failed to find a neat approach to do so. The >>>> difficulty I have met is that PT64_ROOT_MAX_LEVEL is defined together >>>> with PT64_ROOT_4LEVEL/PT32E_ROOT_LEVEL/PT32_ROOT_LEVEL in mmu.h, yet >>>> the rsvd_bits_validate structure is defined in kvm_host.h, which are >>>> included in quite a lot .c files that do not include mmu.h or include >>>> the mmu.h after kvm_host.h. >>>> >>>> I guess that's the reason why the magic number 4 instead of >>>> PT64_ROOT_4LEVEL is used in current definition of >>>> rsvd_bits_vadlidate. :-) >>> Yes, you're right. I think the solution is to define >>> PT64_ROOT_MAX_LEVEL in kvm_host.h. >> Thanks, Paolo. How about we also move the definition of PT64_ROOT_4LEVEL/ >> PT32E_ROOT_LEVEL/PT32_ROOT_LEVEL from mmu.h to kvm_host.h? Then we >> can define PT64_ROOT_MAX_LEVEL as PT64_ROOT_4LEVEL instead of 4 in >> kvm_host.h. > No, I think those are best left in mmu.h. They are only used in mmu > files, except for two occurrences in svm.c. > > kvm_host.h would have PT64_ROOT_MAX_LEVEL just because it is slightly > better than "4" or "5". OK. I can define PT64_ROOT_MAX_LEVEL in kvm_host.h as 4 in patch 2, and change it to 5 in patch 3. :- ) Thanks Yu