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=-15.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, 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 2246FC433DB for ; Mon, 22 Mar 2021 11:29:52 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 B651B61972 for ; Mon, 22 Mar 2021 11:29:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B651B61972 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=oldpddbUaLYv5l92l0Xkn4itTGJLoEt+c343BdqdEaY=; b=ikL3026CozBiuK5xRYZLgs/A6 P5T/AuTVRSu5pvmEffN2cR3fM0EDOdN35aE9rLBfQ1d/ecvF8CXIjx62DxDbdV5/G6G+OGgsdYcWl oX3AmhAORNtlDfAHG2IVgalbhUdhYnaKeNAmr9n6yyKG8SeMW/mF472vqQ1SG+b48z9TeERNWkFCl iiyi3tmMZ8yMM3uZk83na8jPAJcr9UcucNgmy6sbrlObHXL1V84H/k3yhw11UcZyfAFWiIVO+TAi4 eb5EqFkWb2vasLinqLfuOXa0CJVmXspYY1Ro9gXBkTqBtv5Z1Rx1AV406mHel6l2Qrc8KpSqpeCFp FuY03ZaGg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lOIiw-00BSKi-2j; Mon, 22 Mar 2021 11:27:54 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lOIiq-00BSJJ-Ns for linux-arm-kernel@lists.infradead.org; Mon, 22 Mar 2021 11:27:50 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7C85F6191F; Mon, 22 Mar 2021 11:27:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616412467; bh=2rQCKuAt/izeJLTYF4MTljlVoBabkTjdYFUOiQ846kg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hCdtEo/cGqar4OAPPbwzZ28D6YUm9xkGkk1tyTKkmhP5BD0PvzRwzSgkiCBHJAHi3 0Oi+rd9f0hcStg2vT2O9d7ZbUfYzXiJdeqZcXb9Ep/TxIScPofF1zjqC16ZAlJeIxt QsT72YQmboZA/spmbvmXpElGMuaRW9TfpgpoP5EL2NSZNf8MFAJYAM98BddOjwfg2f C1oL7A2WJbicW71oOLiWXHvVnxBpNesdUlv2Gek+l4o+2ydE6+/ijgQs+EiILfSYm+ lPzMM8JFbFyGUpV+oX40F9xnPg1R8+0vIof9WNSw2uQxt47WjJFWBpJdWbMGLtz9xw 1NDgNzSETgyYg== Date: Mon, 22 Mar 2021 11:27:41 +0000 From: Will Deacon To: Quentin Perret Cc: catalin.marinas@arm.com, maz@kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, android-kvm@google.com, seanjc@google.com, mate.toth-pal@arm.com, linux-kernel@vger.kernel.org, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@android.com, kvmarm@lists.cs.columbia.edu, tabba@google.com, ardb@kernel.org, mark.rutland@arm.com, dbrazdil@google.com Subject: Re: [PATCH v6 29/38] KVM: arm64: Use page-table to track page ownership Message-ID: <20210322112741.GC10318@willie-the-truck> References: <20210319100146.1149909-1-qperret@google.com> <20210319100146.1149909-30-qperret@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210319100146.1149909-30-qperret@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210322_112749_130925_6402DBF8 X-CRM114-Status: GOOD ( 15.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Mar 19, 2021 at 10:01:37AM +0000, Quentin Perret wrote: > As the host stage 2 will be identity mapped, all the .hyp memory regions > and/or memory pages donated to protected guestis will have to marked > invalid in the host stage 2 page-table. At the same time, the hypervisor > will need a way to track the ownership of each physical page to ensure > memory sharing or donation between entities (host, guests, hypervisor) is > legal. > > In order to enable this tracking at EL2, let's use the host stage 2 > page-table itself. The idea is to use the top bits of invalid mappings > to store the unique identifier of the page owner. The page-table owner > (the host) gets identifier 0 such that, at boot time, it owns the entire > IPA space as the pgd starts zeroed. > > Provide kvm_pgtable_stage2_set_owner() which allows to modify the > ownership of pages in the host stage 2. It re-uses most of the map() > logic, but ends up creating invalid mappings instead. This impacts > how we do refcount as we now need to count invalid mappings when they > are used for ownership tracking. > > Signed-off-by: Quentin Perret > --- > arch/arm64/include/asm/kvm_pgtable.h | 20 +++++ > arch/arm64/kvm/hyp/pgtable.c | 126 ++++++++++++++++++++++----- > 2 files changed, 122 insertions(+), 24 deletions(-) Acked-by: Will Deacon Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel