From patchwork Fri Sep 2 15:48:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 12964361 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 1D6A2C001B5 for ; Fri, 2 Sep 2022 15:50:28 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Rv87qK2qg3HJPTgsn+fRL46p2OpspsHC995EKCrGjsk=; b=iUWkvNNzLYIf5N r5SXIeoQvxGP5Yl0ILZ+Pt8nXGYGmFGZUUPXa4p7cJGhBelaIy1uS4Zgx7GxFqNI1GpA+So/BSq21 q9h+kE47MrsGBzDRJCy8gg2xPNLuvnFDK+QCGd4WqjkMgoosBcP/JHje7w+SQcn0iBkEYGbHlhOIT f88+SJHsm3lL6D5/LvU96ZL+gG5VC9YXSdzippzmRDoPn1zQ4oF287A+jC6VZF/KBHGWMRaJdGzNV khT/KnQmqQDw5c/l9m4zBNuloEn8QeVdI0qONLwucyUQ6pynV91/V5s2Ze0PATCM/xW3Gjnn8FY5G TkWP9WE2EMTi2ks6a6gg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oU8v9-006U4r-8I; Fri, 02 Sep 2022 15:49:27 +0000 Received: from out0.migadu.com ([94.23.1.103]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oU8uF-006TW4-0z for linux-arm-kernel@lists.infradead.org; Fri, 02 Sep 2022 15:48:32 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1662133709; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/op3CBEinkvTvgamMVY4adnisAOglI/j+DprQ1jnwLs=; b=vSJYzQjTn5JiKKoXkIZFS6sZAL8nglhzH3m1Cc/56eVqKV0nSy+FT02abLWZ1L6hrzWu90 z6eh3xL6WzqfhvTScyYCtYflkQOkDIV6H5YWago7Roz7+NyW2+R+fbnntKdIR6URj8iMNY jDvRIPaeT6UQFQOPBdmyO5uF3ll3Fvo= From: Oliver Upton To: Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Oliver Upton , Catalin Marinas , Will Deacon Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Reiji Watanabe , linux-kernel@vger.kernel.org Subject: [PATCH v2 5/7] KVM: arm64: Add a visibility bit to ignore user writes Date: Fri, 2 Sep 2022 15:48:01 +0000 Message-Id: <20220902154804.1939819-6-oliver.upton@linux.dev> In-Reply-To: <20220902154804.1939819-1-oliver.upton@linux.dev> References: <20220902154804.1939819-1-oliver.upton@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220902_084831_241699_73A82F1D X-CRM114-Status: GOOD ( 12.53 ) 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 We're about to ignore writes to AArch32 ID registers on AArch64-only systems. Add a bit to indicate a register is handled as write ignore when accessed from userspace. Signed-off-by: Oliver Upton Reviewed-by: Reiji Watanabe --- arch/arm64/kvm/sys_regs.c | 3 +++ arch/arm64/kvm/sys_regs.h | 7 +++++++ 2 files changed, 10 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 0e20a311ea20..6d0511247df4 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2775,6 +2775,9 @@ int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, if (!r) return -ENOENT; + if (sysreg_user_write_ignore(vcpu, r)) + return 0; + if (r->set_user) { ret = (r->set_user)(vcpu, r, val); } else { diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h index e78b51059622..e4ebb3a379fd 100644 --- a/arch/arm64/kvm/sys_regs.h +++ b/arch/arm64/kvm/sys_regs.h @@ -86,6 +86,7 @@ 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 */ static __printf(2, 3) inline void print_sys_reg_msg(const struct sys_reg_params *p, @@ -157,6 +158,12 @@ static inline bool sysreg_visible_as_raz(const struct kvm_vcpu *vcpu, return sysreg_visibility(vcpu, r) & REG_RAZ; } +static inline bool sysreg_user_write_ignore(const struct kvm_vcpu *vcpu, + const struct sys_reg_desc *r) +{ + return sysreg_visibility(vcpu, r) & REG_USER_WI; +} + static inline int cmp_sys_reg(const struct sys_reg_desc *i1, const struct sys_reg_desc *i2) {