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 2ACDDC47422 for ; Mon, 29 Jan 2024 12:16:16 +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-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=j3w53iqbRmKdU9n6VvXSxZyyw49uvTVd6rlb60C/sWM=; b=qiqrkn728CgNj4 RuiXLpMuRmOgVZfjvl3c3sE/dkfudSux+DE/Bz/1pQXF5WF9GzDVP9rD/tuQE3fete1FYb5Eq7Jqk fMmzj36oDodJr6vAo4+boV7vxdLuc+okMAw/vMOtsOcOdZA1HTQ6gdJiQQ8G5S9xHF+UoM3GagYAo t4vZ/EU9F0T37ZZpg6v3q0s6oMxBccm43pj7iCdaxBvbPC7hNZXE7uPPQWw4y8OH8oGr/E/i9CCMe J9qTHNwB4npLeMvTgq25vHVzToatE9EYZ+neIVJQ2TfN9JVBY1aVzFU8/tVs9YFP7OYtEA/Bdvdxj M6NWu3COUg3riuJ3MWpQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUQYQ-0000000CZhB-1G02; Mon, 29 Jan 2024 12:15:58 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUQYN-0000000CZfW-1yOS for linux-arm-kernel@lists.infradead.org; Mon, 29 Jan 2024 12:15:57 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 676B61FB; Mon, 29 Jan 2024 04:16:35 -0800 (PST) Received: from [10.1.197.1] (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E7DAE3F5A1; Mon, 29 Jan 2024 04:15:48 -0800 (PST) Message-ID: <95d829b3-d30e-4dcd-a7ca-69d80b9be418@arm.com> Date: Mon, 29 Jan 2024 12:15:47 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V16 2/8] KVM: arm64: Prevent guest accesses into BRBE system registers/instructions Content-Language: en-US To: Anshuman Khandual , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com Cc: Mark Brown , James Clark , Rob Herring , Marc Zyngier , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , linux-perf-users@vger.kernel.org, Oliver Upton , James Morse , kvmarm@lists.linux.dev References: <20240125094119.2542332-1-anshuman.khandual@arm.com> <20240125094119.2542332-3-anshuman.khandual@arm.com> From: Suzuki K Poulose In-Reply-To: <20240125094119.2542332-3-anshuman.khandual@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240129_041555_610141_C6F2AF11 X-CRM114-Status: GOOD ( 16.72 ) 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 25/01/2024 09:41, Anshuman Khandual wrote: > Currently BRBE feature is not supported in a guest environment. This hides > BRBE feature availability via masking ID_AA64DFR0_EL1.BRBE field. This also > blocks guest accesses into BRBE system registers and instructions as if the > underlying hardware never implemented FEAT_BRBE feature. > > Cc: Marc Zyngier > Cc: Oliver Upton > Cc: James Morse > Cc: Suzuki K Poulose > Cc: Catalin Marinas > Cc: Will Deacon > Cc: kvmarm@lists.linux.dev > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual > --- > Changes in V16: > > - Added BRB_INF_SRC_TGT_EL1 macro for corresponding BRB_[INF|SRC|TGT] expansion > > arch/arm64/kvm/sys_regs.c | 56 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 56 insertions(+) > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index 30253bd19917..6a06dc2f0c06 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -1304,6 +1304,11 @@ static int set_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, > return 0; > } > > +#define BRB_INF_SRC_TGT_EL1(n) \ > + { SYS_DESC(SYS_BRBINF##n##_EL1), undef_access }, \ > + { SYS_DESC(SYS_BRBSRC##n##_EL1), undef_access }, \ > + { SYS_DESC(SYS_BRBTGT##n##_EL1), undef_access } \ > + > /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */ > #define DBG_BCR_BVR_WCR_WVR_EL1(n) \ > { SYS_DESC(SYS_DBGBVRn_EL1(n)), \ > @@ -1707,6 +1712,9 @@ static u64 read_sanitised_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, > /* Hide SPE from guests */ > val &= ~ID_AA64DFR0_EL1_PMSVer_MASK; > > + /* Hide BRBE from guests */ > + val &= ~ID_AA64DFR0_EL1_BRBE_MASK; > + > return val; > } > > @@ -2195,6 +2203,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { > { SYS_DESC(SYS_DC_CISW), access_dcsw }, > { SYS_DESC(SYS_DC_CIGSW), access_dcgsw }, > { SYS_DESC(SYS_DC_CIGDSW), access_dcgsw }, > + { SYS_DESC(OP_BRB_IALL), undef_access }, > + { SYS_DESC(OP_BRB_INJ), undef_access }, > heads up: This may conflict with Marc's patches to move the sys instructions to a separate table. But otherwise, looks good to me. Suzuki _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel