From patchwork Tue Sep 13 09:44:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 12974637 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 933A8C6FA8A for ; Tue, 13 Sep 2022 09:45:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231811AbiIMJpT (ORCPT ); Tue, 13 Sep 2022 05:45:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231781AbiIMJpL (ORCPT ); Tue, 13 Sep 2022 05:45:11 -0400 Received: from out0.migadu.com (out0.migadu.com [IPv6:2001:41d0:2:267::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3EDF11C20; Tue, 13 Sep 2022 02:45:07 -0700 (PDT) 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=1663062306; 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=RmvFSZbv6WDm9Kg3YGiCwk2o02yAhCb9+UPvPpOU+S8=; b=DkPTDqiiOPttqXzR+4eHChDtDOjR5LNpIUWbIo8aRVQnKzvKsRV6w4vviLOmUR3z+59s1N 3Lh+CvtbDUnOFBjJIdm60gXZP7D/fZZ+2/iY6dmutpL62myR2uxC30YrUsQFWZlzSbnZVY Ps4/xtJ1ba4N+1ciHC/3fSqrGpktXOM= 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 , Andrew Jones , linux-kernel@vger.kernel.org Subject: [PATCH v3 5/7] KVM: arm64: Add a visibility bit to ignore user writes Date: Tue, 13 Sep 2022 09:44:38 +0000 Message-Id: <20220913094441.3957645-6-oliver.upton@linux.dev> In-Reply-To: <20220913094441.3957645-1-oliver.upton@linux.dev> References: <20220913094441.3957645-1-oliver.upton@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.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) {