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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 078FECA9EA0 for ; Tue, 22 Oct 2019 18:30:43 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 669FA21783 for ; Tue, 22 Oct 2019 18:30:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Mu/wPKo5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 669FA21783 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46yMWd3Xw4zDqMm for ; Wed, 23 Oct 2019 05:30:37 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=redhat.com (client-ip=205.139.110.61; helo=us-smtp-delivery-1.mimecast.com; envelope-from=david@redhat.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="Mu/wPKo5"; dkim-atps=neutral Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46yKqg469gzDqLx for ; Wed, 23 Oct 2019 04:14:23 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571764461; 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=RJLxUYZkphEfv5+PiNRBYPJsBqxuoPsQs816P7mVHAI=; b=Mu/wPKo5RtvUuNRJZ9sinwv0ot8/qTb0saRb828KW5NhpgkWYlVrGdKkCjRu46KLJAJwE7 TlQ4wiGv+Boi+M39U+2qbQ8waQb61iQAVrR3MX5/vllnDukrj34FircnVlhjkJ4ryU2Y1b FFXd+Ity1kizJHN/ai33TGeEhqJuiFs= 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-196-LQ7sslTiPc68PqWCypqf4g-1; Tue, 22 Oct 2019 13:14:18 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C3CE880183D; Tue, 22 Oct 2019 17:14:13 +0000 (UTC) Received: from t460s.redhat.com (ovpn-116-248.ams2.redhat.com [10.36.116.248]) by smtp.corp.redhat.com (Postfix) with ESMTP id 83D8F5ED21; Tue, 22 Oct 2019 17:13:53 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Subject: [PATCH RFC v1 03/12] KVM: x86/mmu: Prepare kvm_is_mmio_pfn() for PG_reserved changes Date: Tue, 22 Oct 2019 19:12:30 +0200 Message-Id: <20191022171239.21487-4-david@redhat.com> In-Reply-To: <20191022171239.21487-1-david@redhat.com> References: <20191022171239.21487-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: LQ7sslTiPc68PqWCypqf4g-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Wed, 23 Oct 2019 05:28:43 +1100 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kate Stewart , Sasha Levin , linux-hyperv@vger.kernel.org, Michal Hocko , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , kvm@vger.kernel.org, David Hildenbrand , KarimAllah Ahmed , Dave Hansen , Alexander Duyck , Michal Hocko , linux-mm@kvack.org, Pavel Tatashin , Paul Mackerras , "H. Peter Anvin" , Wanpeng Li , Alexander Duyck , "K. Y. Srinivasan" , Fabio Estevam , Ben Chan , Kees Cook , devel@driverdev.osuosl.org, Stefano Stabellini , Stephen Hemminger , "Aneesh Kumar K.V" , Joerg Roedel , x86@kernel.org, YueHaibing , Mike Rapoport , Madhumitha Prabakaran , Peter Zijlstra , Ingo Molnar , Vlastimil Babka , Nishka Dasgupta , Anthony Yznaga , Oscar Salvador , Dan Carpenter , "Isaac J. Manjarres" , Matt Sickler , Juergen Gross , Anshuman Khandual , Haiyang Zhang , =?UTF-8?q?Simon=20Sandstr=C3=B6m?= , Dan Williams , kvm-ppc@vger.kernel.org, Qian Cai , Alex Williamson , Mike Rapoport , Borislav Petkov , Nicholas Piggin , Andy Lutomirski , xen-devel@lists.xenproject.org, Boris Ostrovsky , Todd Poynor , Vitaly Kuznetsov , Allison Randal , Jim Mattson , Vandana BN , Jeremy Sowden , Greg Kroah-Hartman , Cornelia Huck , Pavel Tatashin , Mel Gorman , Sean Christopherson , Rob Springer , Thomas Gleixner , Johannes Weiner , Paolo Bonzini , Andrew Morton , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 - however, there is no reliable and fast check to detect memmaps that were initialized and are ZONE_DEVICE. Let's rewrite kvm_is_mmio_pfn() so we really only touch initialized memmaps that are guaranteed to not contain garbage. Make sure that RAM without a memmap is still not detected as MMIO and that ZONE_DEVICE that is not UC/UC-/WC is not detected as MMIO. 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 | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 24c23c66b226..795869ffd4bb 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2962,20 +2962,26 @@ static bool mmu_need_write_protect(struct kvm_vcpu = *vcpu, gfn_t gfn, =20 static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) { +=09struct page *page =3D pfn_to_online_page(pfn); + +=09/* +=09 * Online pages consist of pages managed by the buddy. Especially, +=09 * ZONE_DEVICE pages are never online. Online pages that are reserved +=09 * indicate the zero page and MMIO pages. +=09 */ +=09if (page) +=09=09return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)); + +=09/* +=09 * Anything with a valid memmap could be ZONE_DEVICE - or the +=09 * memmap could be uninitialized. Treat only UC/UC-/WC pages as MMIO. +=09 */ =09if (pfn_valid(pfn)) -=09=09return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)) && -=09=09=09/* -=09=09=09 * Some reserved pages, such as those from NVDIMM -=09=09=09 * DAX devices, are not for MMIO, and can be mapped -=09=09=09 * with cached memory type for better performance. -=09=09=09 * However, the above check misconceives those pages -=09=09=09 * as MMIO, and results in KVM mapping them with UC -=09=09=09 * memory type, which would hurt the performance. -=09=09=09 * Therefore, we check the host memory type in addition -=09=09=09 * and only treat UC/UC-/WC pages as MMIO. -=09=09=09 */ -=09=09=09(!pat_enabled() || pat_pfn_immune_to_uc_mtrr(pfn)); +=09=09return !pat_enabled() || pat_pfn_immune_to_uc_mtrr(pfn); =20 +=09/* +=09 * Any RAM that has no memmap (e.g., mapped via /dev/mem) is not MMIO. +=09 */ =09return !e820__mapped_raw_any(pfn_to_hpa(pfn), =09=09=09=09 pfn_to_hpa(pfn + 1) - 1, =09=09=09=09 E820_TYPE_RAM); --=20 2.21.0