From patchwork Thu Jan 12 19:18:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13098661 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3835FC63797 for ; Thu, 12 Jan 2023 19:28:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240327AbjALT16 (ORCPT ); Thu, 12 Jan 2023 14:27:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238898AbjALT1J (ORCPT ); Thu, 12 Jan 2023 14:27:09 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFC3632199 for ; Thu, 12 Jan 2023 11:21:25 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A0460B81FF6 for ; Thu, 12 Jan 2023 19:21:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A03EC433D2; Thu, 12 Jan 2023 19:21:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673551283; bh=VcE5R6SmkNiedouhMzGZSI0/6/cU30SgVaBgzhk/R6s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KbcVL4forIydBURuGZpe1zlPPispwaBO1FWAaX4d3xtSjHknf5sReruwSQt2zaEbI ItPmadsDEia9UTMzaH9h67PjPL1A5eO6j55T5Zt71LuOBxCR/Kh7uzQTrygZ5Wgutf E07xmJ5KN6VArJCMDLp+ZeLgL/MVpF4Awp6mDTE6RvPPlTkTzEDvh/cyjpGPyKfMer pgv7+8lqrbJSmyJkXIRoD1jg8SSgHdsw1KdCT2NI/t4yDNRXaBPKxPUElknDNXAji1 NNi3H/mWHMB14646Y20X077kWh02ehTdqzoFsoWDa2oaRgb0nCe7BG8loB1x4Tmjr+ +M5hgIDYvPz/w== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pG374-001IWu-4J; Thu, 12 Jan 2023 19:19:46 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Alexandru Elisei , Andre Przywara , Chase Conklin , Christoffer Dall , Ganapatrao Kulkarni , Jintack Lim , Russell King , James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu Subject: [PATCH v7 27/68] KVM: arm64: nv: Allow a sysreg to be hidden from userspace only Date: Thu, 12 Jan 2023 19:18:46 +0000 Message-Id: <20230112191927.1814989-28-maz@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230112191927.1814989-1-maz@kernel.org> References: <20230112191927.1814989-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, alexandru.elisei@arm.com, andre.przywara@arm.com, chase.conklin@arm.com, christoffer.dall@arm.com, gankulkarni@os.amperecomputing.com, jintack@cs.columbia.edu, rmk+kernel@armlinux.org.uk, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org So far, we never needed to distinguish between registers hidden from userspace and being hidden from a guest (they are always either visible to both, or hidden from both). With NV, we have the ugly case of the EL02 and EL12 registers, which are only a view on the EL0 and EL1 registers. It makes absolutely no sense to expose them to userspace, since it already has the canonical view. Add a new visibility flag (REG_HIDDEN_USER) and a new helper that checks for it and REG_HIDDEN when checking whether to expose a sysreg to userspace. Subsequent patches will make use of it. Reviewed-by: Alexandru Elisei Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 6 +++--- arch/arm64/kvm/sys_regs.h | 14 ++++++++++++-- 2 files changed, 15 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 86b8d0c14d26..152b2e52ea47 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -3231,7 +3231,7 @@ int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, int ret; r = id_to_sys_reg_desc(vcpu, reg->id, table, num); - if (!r) + if (!r || sysreg_hidden_user(vcpu, r)) return -ENOENT; if (r->get_user) { @@ -3275,7 +3275,7 @@ int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, return -EFAULT; r = id_to_sys_reg_desc(vcpu, reg->id, table, num); - if (!r) + if (!r || sysreg_hidden_user(vcpu, r)) return -ENOENT; if (sysreg_user_write_ignore(vcpu, r)) @@ -3369,7 +3369,7 @@ static int walk_one_sys_reg(const struct kvm_vcpu *vcpu, if (!(rd->reg || rd->get_user)) return 0; - if (sysreg_hidden(vcpu, rd)) + if (sysreg_hidden_user(vcpu, rd)) return 0; if (!copy_reg_to_user(rd, uind)) diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h index e4ebb3a379fd..6b11f2cc7146 100644 --- a/arch/arm64/kvm/sys_regs.h +++ b/arch/arm64/kvm/sys_regs.h @@ -85,8 +85,9 @@ struct sys_reg_desc { }; #define REG_HIDDEN (1 << 0) /* hidden from userspace and guest */ -#define REG_RAZ (1 << 1) /* RAZ from userspace and guest */ -#define REG_USER_WI (1 << 2) /* WI from userspace only */ +#define REG_HIDDEN_USER (1 << 1) /* hidden from userspace only */ +#define REG_RAZ (1 << 2) /* RAZ from userspace and guest */ +#define REG_USER_WI (1 << 3) /* WI from userspace only */ static __printf(2, 3) inline void print_sys_reg_msg(const struct sys_reg_params *p, @@ -152,6 +153,15 @@ static inline bool sysreg_hidden(const struct kvm_vcpu *vcpu, return sysreg_visibility(vcpu, r) & REG_HIDDEN; } +static inline bool sysreg_hidden_user(const struct kvm_vcpu *vcpu, + const struct sys_reg_desc *r) +{ + if (likely(!r->visibility)) + return false; + + return r->visibility(vcpu, r) & (REG_HIDDEN | REG_HIDDEN_USER); +} + static inline bool sysreg_visible_as_raz(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) {