From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F3A32284896 for ; Tue, 13 Jan 2026 14:19:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768313965; cv=none; b=sFLliY8U+cK1pVvEKfVO9t0ujXbn1xwMjkdLLpAv0kK7p2lLJQ+O2jyXQfa5Ow6CmJ+2orQGfxvPUsQDAT16hRpfbpRBZvZV6UAr3jOgw/1NYmt3IZKCeZlvs7FnFjzOsue/W73rgzjQHl3mt8R/1z/t4pqWk5EfPbK85i7qeSA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768313965; c=relaxed/simple; bh=ZyR8TQ153JkeglmvwcRTy5JNkPjlYmWSxCduT/6f3oo=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ltr5u4gaLdVDUDeTLZ1/5Uk6UjfZvzURDailrE5Nql1lwMsOaau/cihIHi04LqEDegcAk4RVh21rANOf7aaWwpfwCR/kV/aUwPtgTN+fSjSicaXEkbybNznrZnGzPDI34X5D6VrKbD8/EPBNQsd5zyrMaoyetCRPt5EbPgteSh8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com 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) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml100009.china.huawei.com (7.191.174.83) To dubpeml100005.china.huawei.com (7.214.146.113) 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