From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v3 7/8] kvm: x86: mmu: Lockless access tracking for Intel CPUs without EPT A bits. Date: Tue, 20 Dec 2016 10:01:12 +0100 Message-ID: <2c76bc86-39a3-8de5-da40-e1895acfd2bd@redhat.com> References: <4157789.R9cn7kUSZu@js-desktop.mtv.corp.google.com> <1942485779.4450132.1481984369832.JavaMail.zimbra@redhat.com> <2941755.AtdGOR38c0@js-desktop.mtv.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: Xiao Guangrong , kvm@vger.kernel.org, andreslc@google.com, pfeiner@google.com To: Junaid Shahid Return-path: Received: from mx1.redhat.com ([209.132.183.28]:39632 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755648AbcLTJBQ (ORCPT ); Tue, 20 Dec 2016 04:01:16 -0500 In-Reply-To: <2941755.AtdGOR38c0@js-desktop.mtv.corp.google.com> Sender: kvm-owner@vger.kernel.org List-ID: On 20/12/2016 04:36, Junaid Shahid wrote: > > On Saturday, December 17, 2016 09:19:29 AM Paolo Bonzini wrote: >>> >>> Yes, I guess we can do that since if the restored PTE doesn’t satisfy the >>> access we are just going to get another fault anyway. >> >> Please do it as a follow up, since it complicates the logic a bit. >> >> .... >>> >>> Ok. So you mean that vmx.c should just pass VMX_EPT_RWX_MASK here and >>> VMX_EPT_MISCONFIG_WX_VALUE for the mmio mask and then mmu.c should add in >>> SPTE_SPECIAL_MASK before storing these values in shadow_acc_track_mask and >>> shadow_mmio_mask? >> >> I think I agree, but we can do this too as a separate follow-up cleanup patch. >> > > Sure. I’ll defer these to follow-up patches. What about the change to move the pgtable walk inside the retry loop in fast_page_fault? Should I update the current patch-set to do that or should we defer that to a later patch as well? Please separate everything. Paolo