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 54424103E19E for ; Wed, 18 Mar 2026 15:57:27 +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: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=O0cusI1ZB9OhVNs77Idf8i7gTZk8DkZ2iUUsoda/tmE=; b=n+Y/PCub89WVdZPnCUslCb0j8n 2Uu7Ln82B/+pZE/w7TdUCRgK04lbS00Y7GFjZvIxHlD0HBaMx9iRmQE6WqIYEfO3yvpklQOPxDit4 3/mf8IeXuKqACobNR2Ex6i/VRGui0Nzvs9fIDthU+fsirtyYy1u6ntUU/VtCKNJWDa5QMidp7FC99 jn5j9xwqiyrGiaLWb/JPPoKDO36tcfH/qq+d85mnsGFMdWWVndb79fmvfngh+vdrf8HcamDPH3mf1 L8kN/oAYKkIM5h90IterwxoE5E60i7s/quZbf4DVWO/PsyYoAkVHJCox9aLgDhtclhsT74ctocKnD yQeGk+vA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2tGp-00000008qd6-0wIT; Wed, 18 Mar 2026 15:57:19 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2tGO-00000008q6n-35fb for linux-arm-kernel@bombadil.infradead.org; Wed, 18 Mar 2026 15:56:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:MIME-Version :References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=O0cusI1ZB9OhVNs77Idf8i7gTZk8DkZ2iUUsoda/tmE=; b=gWmRZXvSimrH5bu81dZOKqcKxP XezMgAwQEzR30CPTlCAGSHMBsu6ueZ0RtWqc17rGvrQzq5OcJwKxRC2UDIxm37aJP6g5DGexCNngu 0aRa3vNqgOfdnkrtoNUocYQ0WxqaffVJbaViicEK3BCZwew4Av3mtRvNW48EQJJY9eQj1/q3ZA5QQ m5wSNcfNqmKNoDEUXzgabPa38Vr3gDSXUHnzWqbjYRFU1Q5NEVjPRXfmKq0yT3Xj1Fjgp4K3cusBV 8712YChEOseH0Gnhw6sYsuc/70myuimWHgn4Xg4R8Ph8xQfpLIiNn6vPJRObXHJmOTw+iYR9pFbb3 unG7vi3A==; Received: from foss.arm.com ([217.140.110.172]) by desiato.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2tGK-0000000Bdvm-2rhg for linux-arm-kernel@lists.infradead.org; Wed, 18 Mar 2026 15:56:50 +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 DEF311C2B; Wed, 18 Mar 2026 08:56:40 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.61.122]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9EAA83F73B; Wed, 18 Mar 2026 08:56:43 -0700 (PDT) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Jean-Philippe Brucker , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve , Steven Price Subject: [PATCH v13 39/48] arm64: RMI: Propagate number of breakpoints and watchpoints to userspace Date: Wed, 18 Mar 2026 15:54:03 +0000 Message-ID: <20260318155413.793430-40-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260318155413.793430-1-steven.price@arm.com> References: <20260318155413.793430-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260318_155649_131658_8BE3EE30 X-CRM114-Status: GOOD ( 11.68 ) 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 From: Jean-Philippe Brucker The RMM describes the maximum number of BPs/WPs available to the guest in the Feature Register 0. Propagate those numbers into ID_AA64DFR0_EL1, which is visible to userspace. A VMM needs this information in order to set up realm parameters. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Steven Price Reviewed-by: Gavin Shan Reviewed-by: Suzuki K Poulose Reviewed-by: Joey Gouly --- arch/arm64/include/asm/kvm_rmi.h | 2 ++ arch/arm64/kvm/rmi.c | 22 ++++++++++++++++++++++ arch/arm64/kvm/sys_regs.c | 2 +- 3 files changed, 25 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h index 17bb7e2a2aa0..8fb526764c30 100644 --- a/arch/arm64/include/asm/kvm_rmi.h +++ b/arch/arm64/include/asm/kvm_rmi.h @@ -87,6 +87,8 @@ struct realm_rec { void kvm_init_rmi(void); u32 kvm_realm_ipa_limit(void); +u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val); + bool kvm_rmi_supports_sve(void); bool kvm_rmi_supports_pmu(void); diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c index 8dc090da6e5f..01519d934d3a 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -212,6 +212,28 @@ u32 kvm_realm_ipa_limit(void) return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_S2SZ); } +u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val) +{ + u32 bps = u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_NUM_BPS); + u32 wps = u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_NUM_WPS); + u32 ctx_cmps; + + if (!kvm_is_realm(vcpu->kvm)) + return val; + + /* Ensure CTX_CMPs is still valid */ + ctx_cmps = FIELD_GET(ID_AA64DFR0_EL1_CTX_CMPs, val); + ctx_cmps = min(bps, ctx_cmps); + + val &= ~(ID_AA64DFR0_EL1_BRPs_MASK | ID_AA64DFR0_EL1_WRPs_MASK | + ID_AA64DFR0_EL1_CTX_CMPs); + val |= FIELD_PREP(ID_AA64DFR0_EL1_BRPs_MASK, bps) | + FIELD_PREP(ID_AA64DFR0_EL1_WRPs_MASK, wps) | + FIELD_PREP(ID_AA64DFR0_EL1_CTX_CMPs, ctx_cmps); + + return val; +} + static int get_start_level(struct realm *realm) { return 4 - stage2_pgtable_levels(realm->ia_bits); diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 46f5e2ab3e2c..83b5c36f43bf 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2043,7 +2043,7 @@ static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val) /* Hide BRBE from guests */ val &= ~ID_AA64DFR0_EL1_BRBE_MASK; - return val; + return kvm_realm_reset_id_aa64dfr0_el1(vcpu, val); } /* -- 2.43.0