From mboxrd@z Thu Jan 1 00:00:00 1970 From: Barret Rhoden Subject: Re: [PATCH 2/2] kvm: Use huge pages for DAX-backed files Date: Tue, 13 Nov 2018 10:56:28 -0500 Message-ID: <20181113105628.37449f52@gnomeregan.cam.corp.google.com> References: <20181109203921.178363-1-brho@google.com> <20181109203921.178363-3-brho@google.com> <043a592d-6592-3053-15a0-68cc54a26deb@redhat.com> <286665658.33247363.1542103353780.JavaMail.zimbra@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, yu c zhang , kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, David Hildenbrand , Radim =?UTF-8?B?S3LEjW3DocWZ?= , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, Ingo Molnar , Borislav Petkov , Ross Zwisler , Paolo Bonzini , "H. Peter Anvin" , Thomas Gleixner , yi z zhang To: Pankaj Gupta Return-path: In-Reply-To: <286665658.33247363.1542103353780.JavaMail.zimbra-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: kvm.vger.kernel.org On 2018-11-13 at 05:02 Pankaj Gupta wrote: > As this patch is dependent on PageReserved patch(which is in progress), just > wondering if we are able to test the code path for hugepage with DAX. For testing, I used the following patch. It's not 100%, since it intercepts at kvm_is_reserved_pfn(), and not PageReserved() directly. The only difference is with kvm_set_pfn_dirty() I think. I also have a nasty module that would dump the EPT's and the host page table's mappings so I could confirm that the huge pages are being mapped correctly. ----------------------- diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2679e476b6c3..1b394a0752a0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -148,6 +148,10 @@ __weak int kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, bool kvm_is_reserved_pfn(kvm_pfn_t pfn) { + // XXX hack + if (is_zone_device_page(pfn_to_page(pfn))) + return false; + if (pfn_valid(pfn)) return PageReserved(pfn_to_page(pfn)); ----------------------- Thanks, Barret