From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55750C010A2 for ; Tue, 5 Nov 2019 11:10:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E297120869 for ; Tue, 5 Nov 2019 11:10:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WttzqtvS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E297120869 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 42A726B0003; Tue, 5 Nov 2019 06:10:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3B3456B0006; Tue, 5 Nov 2019 06:10:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2553E6B0007; Tue, 5 Nov 2019 06:10:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0072.hostedemail.com [216.40.44.72]) by kanga.kvack.org (Postfix) with ESMTP id 080A76B0003 for ; Tue, 5 Nov 2019 06:10:03 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id A66B545DA for ; Tue, 5 Nov 2019 11:10:02 +0000 (UTC) X-FDA: 76121954244.29.angle07_1d489ffdb8d0c X-HE-Tag: angle07_1d489ffdb8d0c X-Filterd-Recvd-Size: 7757 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Tue, 5 Nov 2019 11:10:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572952200; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FREnvreZ0DXlMswNBUBVaTmUA3OlcxYKpKYODf+ZHzI=; b=WttzqtvScM34sSHJCeqzftEiuUfyBlP8Bts8+PBSOJBJTCBgEDenhqtojWzPd82lKoKtsK uPg3XN+uFHn9Vn6AExd/XuXYrZnGkT4oAl32O9/gY0i97l4g/NRa8cRAiI6PRRFWqJqybQ EvLMV+k7qH9a/pVp9Zj7/vGwzvRh4ag= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-219-JwYfLl3JMpuPum529BzIzg-1; Tue, 05 Nov 2019 06:09:58 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2C6EC801FCB; Tue, 5 Nov 2019 11:09:52 +0000 (UTC) Received: from [10.36.117.253] (ovpn-117-253.ams2.redhat.com [10.36.117.253]) by smtp.corp.redhat.com (Postfix) with ESMTP id 15277608B5; Tue, 5 Nov 2019 11:09:33 +0000 (UTC) Subject: Re: [PATCH v1 02/10] KVM: x86/mmu: Prepare kvm_is_mmio_pfn() for PG_reserved changes To: Dan Williams Cc: Linux Kernel Mailing List , Linux MM , Michal Hocko , Andrew Morton , kvm-ppc@vger.kernel.org, linuxppc-dev , KVM list , linux-hyperv@vger.kernel.org, devel@driverdev.osuosl.org, xen-devel , X86 ML , Alexander Duyck , Alexander Duyck , Alex Williamson , Allison Randal , Andy Lutomirski , "Aneesh Kumar K.V" , Anshuman Khandual , Anthony Yznaga , Benjamin Herrenschmidt , Borislav Petkov , Boris Ostrovsky , Christophe Leroy , Cornelia Huck , Dave Hansen , Haiyang Zhang , "H. Peter Anvin" , Ingo Molnar , "Isaac J. Manjarres" , Jim Mattson , Joerg Roedel , Johannes Weiner , Juergen Gross , KarimAllah Ahmed , Kees Cook , "K. Y. Srinivasan" , "Matthew Wilcox (Oracle)" , Matt Sickler , Mel Gorman , Michael Ellerman , Michal Hocko , Mike Rapoport , Mike Rapoport , Nicholas Piggin , Oscar Salvador , Paolo Bonzini , Paul Mackerras , Paul Mackerras , Pavel Tatashin , Pavel Tatashin , Peter Zijlstra , Qian Cai , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Sasha Levin , Sean Christopherson , Stefano Stabellini , Stephen Hemminger , Thomas Gleixner , Vitaly Kuznetsov , Vlastimil Babka , Wanpeng Li , YueHaibing References: <20191024120938.11237-1-david@redhat.com> <20191024120938.11237-3-david@redhat.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <91df87ad-bbc5-aa9e-653f-d68c3c322978@redhat.com> Date: Tue, 5 Nov 2019 12:09:33 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: JwYfLl3JMpuPum529BzIzg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 05.11.19 02:37, Dan Williams wrote: > On Thu, Oct 24, 2019 at 5:10 AM David Hildenbrand wrot= e: >> >> Right now, ZONE_DEVICE memory is always set PG_reserved. We want to >> change that. >> >> KVM has this weird use case that you can map anything from /dev/mem >> into the guest. pfn_valid() is not a reliable check whether the memmap >> was initialized and can be touched. pfn_to_online_page() makes sure >> that we have an initialized memmap (and don't have ZONE_DEVICE memory). >> >> Rewrite kvm_is_mmio_pfn() to make sure the function produces the >> same result once we stop setting ZONE_DEVICE pages PG_reserved. >> >> Cc: Paolo Bonzini >> Cc: "Radim Kr=C4=8Dm=C3=A1=C5=99" >> Cc: Sean Christopherson >> Cc: Vitaly Kuznetsov >> Cc: Wanpeng Li >> Cc: Jim Mattson >> Cc: Joerg Roedel >> Cc: Thomas Gleixner >> Cc: Ingo Molnar >> Cc: Borislav Petkov >> Cc: "H. Peter Anvin" >> Cc: KarimAllah Ahmed >> Cc: Michal Hocko >> Cc: Dan Williams >> Signed-off-by: David Hildenbrand >> --- >> arch/x86/kvm/mmu.c | 29 +++++++++++++++++------------ >> 1 file changed, 17 insertions(+), 12 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index 24c23c66b226..f03089a336de 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -2962,20 +2962,25 @@ static bool mmu_need_write_protect(struct kvm_vc= pu *vcpu, gfn_t gfn, >> >> static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) >> { >> + struct page *page =3D pfn_to_online_page(pfn); >> + >> + /* >> + * ZONE_DEVICE pages are never online. Online pages that are res= erved >> + * either indicate the zero page or MMIO pages. >> + */ >> + if (page) >> + return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn= )); >> + >> + /* >> + * Anything with a valid (but not online) memmap could be ZONE_D= EVICE. >> + * Treat only UC/UC-/WC pages as MMIO. >=20 > You might clarify that ZONE_DEVICE pages that belong to WB cacheable > pmem have the correct memtype established by devm_memremap_pages(). /* * Anything with a valid (but not online) memmap could be ZONE_DEVICE. * Treat only UC/UC-/WC pages as MMIO. devm_memremap_pages() established * the correct memtype for WB cacheable ZONE_DEVICE pages. */ Thanks! >=20 > Other than that, feel free to add: >=20 > Reviewed-by: Dan Williams >=20 --=20 Thanks, David / dhildenb