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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E780C433E0 for ; Tue, 26 May 2020 16:29:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E73320787 for ; Tue, 26 May 2020 16:29:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729769AbgEZQ3p (ORCPT ); Tue, 26 May 2020 12:29:45 -0400 Received: from foss.arm.com ([217.140.110.172]:53280 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729594AbgEZQ3p (ORCPT ); Tue, 26 May 2020 12:29:45 -0400 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 C352B30E; Tue, 26 May 2020 09:29:44 -0700 (PDT) Received: from [192.168.0.14] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C53183F52E; Tue, 26 May 2020 09:29:42 -0700 (PDT) From: James Morse Subject: Re: [PATCH 19/26] KVM: arm64: Make struct kvm_regs userspace-only To: Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Andre Przywara , Christoffer Dall , Dave Martin , Jintack Lim , Alexandru Elisei , George Cherian , "Zengtao (B)" , Will Deacon , Catalin Marinas , Mark Rutland , Julien Thierry , Suzuki K Poulose References: <20200422120050.3693593-1-maz@kernel.org> <20200422120050.3693593-20-maz@kernel.org> Message-ID: <0a38305f-77f8-11b0-cb74-2bec07ce0a0a@arm.com> Date: Tue, 26 May 2020 17:29:41 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200422120050.3693593-20-maz@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Marc, On 22/04/2020 13:00, Marc Zyngier wrote: > struct kvm_regs is used by userspace to indicate which register gets > accessed by the {GET,SET}_ONE_REG API. But as we're about to refactor > the layout of the in-kernel register structures, we need the kernel to > move away from it. > > Let's make kvm_regs userspace only, and let the kernel map it to its own > internal representation. > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c > index 23ebe51410f06..9fec9231b63e2 100644 > --- a/arch/arm64/kvm/guest.c > +++ b/arch/arm64/kvm/guest.c > @@ -102,6 +102,55 @@ static int core_reg_size_from_offset(const struct kvm_vcpu *vcpu, u64 off) > return size; > } > > +static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > +{ > + u64 off = core_reg_offset_from_id(reg->id); > + > + switch (off) { > + default: > + return NULL; Doesn't this switch statement catch an out of range offset, and a misaligned offset? ... We still test for those explicitly in the caller. Better safe than implicit? > + } > +} With the reset thing reported by Zenghui and Zengtao on the previous patch fixed: Reviewed-by: James Morse (otherwise struct kvm_regs isn't userspace-only!) Thanks, James