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 D7A11D2D10D for ; Tue, 13 Jan 2026 14:19:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To: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=uwu93khu8v5XO73UrkFCBry/W0irdFXIwCCGsh5usSY=; b=dnVggMUR0xpj7iXzyAHNcBbiGT AZvaTUv4+R8trFIV4biTpPtQnC54yQjOBPSTJW7mrOa93L/JpF7qpVq2jxKnOU+w3Qh27uIMOQaqz 5CdnOZKirB6jHzrpWs/fFCW034rVXC0chieqz2khMrUDzTJyLj8FlGyDXuMdFeUU6jtE7UjTi1P/9 JEMWYJWLKnff+iliMtsm2lOiGjZcIsxM0Xl02nhnoqM+HCtSbsSYkOtGdXKhigQbgvSEnU6qTmnKa vD428jYmQ2uaJVjhWrG+zZ+IqQY0sJ49U9kJ30ZlfQxEdKjoHWkkRd7JnC3oFF0y8G4Vb4Nfry2Ra XF+youzg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vffF9-00000007Egi-1Tm1; Tue, 13 Jan 2026 14:19:35 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vffEz-00000007Ecq-26n0 for linux-arm-kernel@lists.infradead.org; Tue, 13 Jan 2026 14:19:28 +0000 Received: from mail.maildlp.com (unknown [172.18.224.150]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4drBFQ24VCzJ46Bs; Tue, 13 Jan 2026 22:19:06 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 64C6540563; Tue, 13 Jan 2026 22:19:19 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Tue, 13 Jan 2026 14:19:18 +0000 Date: Tue, 13 Jan 2026 14:19:16 +0000 From: Jonathan Cameron To: Ben Horgan CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v3 12/47] KVM: arm64: Force guest EL1 to use user-space's partid configuration Message-ID: <20260113141916.000018b8@huawei.com> In-Reply-To: <20260112165914.4086692-13-ben.horgan@arm.com> References: <20260112165914.4086692-1-ben.horgan@arm.com> <20260112165914.4086692-13-ben.horgan@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml100009.china.huawei.com (7.191.174.83) To dubpeml100005.china.huawei.com (7.214.146.113) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260113_061925_689891_601A29DC X-CRM114-Status: GOOD ( 10.59 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 12 Jan 2026 16:58:39 +0000 Ben Horgan wrote: > From: James Morse > > While we trap the guest's attempts to read/write the MPAM control > registers, the hardware continues to use them. Guest-EL0 uses KVM's > user-space's configuration, as the value is left in the register, and > guest-EL1 uses either the host kernel's configuration, or in the case of > VHE, the UNKNOWN reset value of MPAM1_EL1. > > We want to force the guest-EL1 to use KVM's user-space's MPAM > configuration. On nVHE rely on MPAM0_EL1 and MPAM1_EL1 always being > programmed the same and on VHE copy MPAM0_EL1 into the guest's > MPAM1_EL1. There is no need to restore as this is out of context once TGE > is set. > > Signed-off-by: James Morse > Signed-off-by: Ben Horgan Reviewed-by: Jonathan Cameron