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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AEC2CC4345F for ; Wed, 1 May 2024 17:48:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; 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=ani/vzAgj/1M35mdbvMYpIH7s8rDW1cW8ynhbl6rMUE=; b=1WKI0lr0R8dL2A BUXghm/BGjVX9DDrLAdHVaymyyeJoHvGyDQDQKXWhXtNBNzQFY48ib8KQH5o4zhm5ts8+6x5NamUt 5fD1kixNggtk2D4Hh+RpQwK/nfItGHvFPuzooEnEXTmmjOY9MW7nmEGtJwYFqwClJiAexj20dK1am 8MXQizsBVTZq6uilDVv2A4LEFRZAvR7a70TsG2IfG8LGOGVKNwTye/KGIMWHBzou66u9UCU7L3+K6 gJAH3YpEGDpAqnE3+K9G+WnFiZnHiDg4hr3uUwDR6AgbM+xNPdiVguLOsLztOE+TUKDC3LmxmNNZq m4XMJjYylHlyP2wwH3yA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1s2E3b-0000000ALj9-38P6; Wed, 01 May 2024 17:47:51 +0000 Received: from out-173.mta0.migadu.com ([91.218.175.173]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1s2E3X-0000000ALhp-2pCr for linux-arm-kernel@lists.infradead.org; Wed, 01 May 2024 17:47:49 +0000 Date: Wed, 1 May 2024 17:47:40 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1714585664; 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: in-reply-to:in-reply-to:references:references; bh=yDJUUdp8ULPIC4L+2eqNBMvqRsFS5KecxcGEHAt4XSo=; b=T8PE2vztU71RhSxxtea777/ypUHS02ctMoptEmeyo+QqDRtvOscpSfQhBNsgbNow1P1l/U BlqwL1C5N9zRcGVes9ydIZelZPzcszVTrT1bDx5/nRncpempgSRuAojz9Cejm7zZjkaGA0 KTX1iGWinS5wWCbHqKv335DoitrXDFs= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Will Deacon Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Marc Zyngier Subject: Re: [PATCH 2/2] KVM: arm64: Use hVHE in pKVM by default on CPUs with VHE support Message-ID: References: <20240501163400.15838-1-will@kernel.org> <20240501163400.15838-3-will@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240501163400.15838-3-will@kernel.org> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240501_104747_888277_D0A7B349 X-CRM114-Status: GOOD ( 13.21 ) 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 Wed, May 01, 2024 at 05:34:00PM +0100, Will Deacon wrote: > The early command line parsing treats "kvm-arm.mode=protected" as an > alias for "id_aa64mmfr1.vh=0", forcing the use of nVHE so that the host > kernel runs at EL1 with the pKVM hypervisor at EL2. > > With the introduction of hVHE support in ad744e8cb346 ("arm64: Allow > arm64_sw.hvhe on command line"), the hypervisor can run using the EL2+0 > translation regime. This is interesting for unusual CPUs that have VH > stuck to 1, but also because it opens the possibility of a hypervisor > "userspace" in the distant future which could be used to isolate vCPU > contexts in the hypervisor (see Marc's talk from KVM Forum 2022 [1]). > > Repaint the "kvm-arm.mode=protected" alias to map to "arm64_sw.hvhe=1", > which will use hVHE on CPUs that support it and remain with nVHE > otherwise. > > [1] https://www.youtube.com/watch?v=1F_Mf2j9eIo > Signed-off-by: Will Deacon Acked-by: Oliver Upton -- Thanks, Oliver _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel