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=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 F0D9CC433DF for ; Sun, 5 Jul 2020 18:11:45 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 7516020720 for ; Sun, 5 Jul 2020 18:11:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="r668MgQ/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7516020720 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1B7354B1AE; Sun, 5 Jul 2020 14:11:45 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id YKNSGk-Oq5hA; Sun, 5 Jul 2020 14:11:44 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 0BD6A4B1A7; Sun, 5 Jul 2020 14:11:44 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C0D664B1A7 for ; Sun, 5 Jul 2020 14:11:42 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RyA3T41Q+-oD for ; Sun, 5 Jul 2020 14:11:41 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id CB4044B1A5 for ; Sun, 5 Jul 2020 14:11:41 -0400 (EDT) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B424820720; Sun, 5 Jul 2020 18:11:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593972700; bh=35Aa+KpBnotH0KDmL3yvxY8C5Ay/bKSt6QiE0SJmnWY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=r668MgQ/+j0d0LCpt5Kv+qjH/oSkaV4yuWsP/ggxGHVXC/Y1Q7UBF5uWR9lNb1YHZ Ysjp7QhpnkevlOESm2VPecTB+paLK49FpEiHTzutqPtNQLlR/Ha7BDe3gUDQybF3fy mgB61NEZxJtKj9hayT/uKWFijXCJ8zkk4/cpZzLg= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1js975-009DlO-8K; Sun, 05 Jul 2020 19:11:39 +0100 Date: Sun, 05 Jul 2020 19:11:38 +0100 Message-ID: <87o8otesrp.wl-maz@kernel.org> From: Marc Zyngier To: Alexander Graf Subject: Re: [PATCH] KVM: arm64: Change default caching mode for {PEND, PROP}BASER.outer In-Reply-To: <20200701140206.8664-1-graf@amazon.com> References: <20200701140206.8664-1-graf@amazon.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 EasyPG/1.0.0 Emacs/26.3 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: graf@amazon.com, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Wed, 01 Jul 2020 15:02:06 +0100, Alexander Graf wrote: > > PENDBASER and PROPBASER define the outer caching mode for LPI tables. > The memory backing them may not be outer sharable, so we mark them as nC > by default. This however, breaks Windows on ARM which only accepts > SameAsInner or RaWaWb as values for outer cachability. > > We do today already allow the outer mode to be set to SameAsInner > explicitly, so the easy fix is to default to that instead of nC for > situations when an OS asks for a not fulfillable cachability request. > > This fixes booting Windows in KVM with vgicv3 and ITS enabled for me. > > Signed-off-by: Alexander Graf > --- > arch/arm64/kvm/vgic/vgic-mmio-v3.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c > index d2339a2b9fb9..5c786b915cd3 100644 > --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c > +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c > @@ -389,7 +389,7 @@ u64 vgic_sanitise_outer_cacheability(u64 field) > case GIC_BASER_CACHE_nC: > return field; > default: > - return GIC_BASER_CACHE_nC; > + return GIC_BASER_CACHE_SameAsInner; > } > } > I am going to provisionally queue this for 5.9, with the explicit reserve that it will be reverted if it causes a regression for other guests (as this is an observable change in behaviour). Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm