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=-6.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C980ACA9ED3 for ; Tue, 5 Nov 2019 01:37:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 74A6C20717 for ; Tue, 5 Nov 2019 01:37:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="qw3wPwnJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 74A6C20717 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C4EE6B0003; Mon, 4 Nov 2019 20:37:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 076C06B0008; Mon, 4 Nov 2019 20:37:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EA5E66B000A; Mon, 4 Nov 2019 20:37:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0100.hostedemail.com [216.40.44.100]) by kanga.kvack.org (Postfix) with ESMTP id D2FC16B0003 for ; Mon, 4 Nov 2019 20:37:40 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 85A7D180AD815 for ; Tue, 5 Nov 2019 01:37:40 +0000 (UTC) X-FDA: 76120511880.27.man09_7cfa0663a9b14 X-HE-Tag: man09_7cfa0663a9b14 X-Filterd-Recvd-Size: 7651 Received: from mail-qt1-f196.google.com (mail-qt1-f196.google.com [209.85.160.196]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Tue, 5 Nov 2019 01:37:38 +0000 (UTC) Received: by mail-qt1-f196.google.com with SMTP id y10so20277104qto.3 for ; Mon, 04 Nov 2019 17:37:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=W2L5Wt9vAPwi2DADGCrJo4/gpgrXJ/vHj0hp5uT1/6w=; b=qw3wPwnJQEPIsA7f/w0mDIf51WQSqHZtNBtHkQ+a6qdpUzMOEXt/OAxm9io3JhbfP6 vTne7iEDoazWXW5xBbihS1O0cnamLcICRUtMB42yA1LqBFurawpARa+pI/loQ7TZozCS muNK+/gOteA/6DrrAtwCv6qzAGFDNLrT4lxpVufIgKeSiYXHaqk5RVXbSWJ1ueKtHuiv oOY+F9gg4Xa4vW+/ls61g41NWotER0Buor3x0J0NDaC4S7Hry/ZYzIQIeOoT7pjyK/9n KejzKKo5jxtmx28oPc0/OrVyt4Yy1MBj0AZXomNXumyf6TV3OJA/dy91Qa7O4iQ+cyCX +Lwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=W2L5Wt9vAPwi2DADGCrJo4/gpgrXJ/vHj0hp5uT1/6w=; b=RIKuTBYU8pZQE7wgJASjEH0+6mxhYq6csKZuPAyOvX4lJltwXLAYBG5gIzgIw3st0b WWm1UClDt9NLJsas9XZQCOgtqraELtgxVEZ1TYPq8jrER5VYUD3aShvVCRVQjLdwnIT/ ZRq3FRjSkS1AgqHgu4Hc0lUT4smFIgzutEUFsH/uQioKQcwpM7MiozDFbmy2INxvF9gS dBtm4FLYaIEE3bk6GoWGOfrf/qdoSDm2fwajt7vJ3/uoopauTikHFAiWFOcKrHTJrjtc A1skzrrSfNOi5pB+jiFA450MYd/YFOfjSp+BYbBzQ2YOqp1hLaXZLgVY4sX55WaVgfHf zkTA== X-Gm-Message-State: APjAAAXITboWXoqAmaaltN05ar3pQcze/HpzyH/QtkJcvCamCXNmuRK9 Vvw5whI7X0tudnigEpSYs8Y0tQnJML0Vj3IcLED03g== X-Google-Smtp-Source: APXvYqxf5b5k2/XEh51ut95Lrfer14ii/6Y4WgnKt5ObxWvYMWg+IxU5wRUlwhcOOGIDRGfOdEah46THNJk1jv52R/0= X-Received: by 2002:a0c:a910:: with SMTP id y16mr12413788qva.89.1572917858090; Mon, 04 Nov 2019 17:37:38 -0800 (PST) MIME-Version: 1.0 References: <20191024120938.11237-1-david@redhat.com> <20191024120938.11237-3-david@redhat.com> In-Reply-To: <20191024120938.11237-3-david@redhat.com> From: Dan Williams Date: Mon, 4 Nov 2019 17:37:27 -0800 Message-ID: Subject: Re: [PATCH v1 02/10] KVM: x86/mmu: Prepare kvm_is_mmio_pfn() for PG_reserved changes To: David Hildenbrand 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 Content-Type: text/plain; charset="UTF-8" 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 Thu, Oct 24, 2019 at 5:10 AM David Hildenbrand wrote: > > 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_vcp= u *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 rese= rved > + * 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_DE= VICE. > + * Treat only UC/UC-/WC pages as MMIO. You might clarify that ZONE_DEVICE pages that belong to WB cacheable pmem have the correct memtype established by devm_memremap_pages(). Other than that, feel free to add: Reviewed-by: Dan Williams