From patchwork Tue Dec 11 23:28:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Martin X-Patchwork-Id: 10725247 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9A7EB6C5 for ; Tue, 11 Dec 2018 23:33:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8726529CAA for ; Tue, 11 Dec 2018 23:33:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 77E6929EEE; Tue, 11 Dec 2018 23:33:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id ED74129CAA for ; Tue, 11 Dec 2018 23:33:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=N8P7hf9+tHOWeEjWpVPkbx2VeTg4Qij0oqgGv+D9O6s=; b=oLyNEfQNQCho9IGPGvHLeEL0hS vkv5fiXYLUuYHrq1kT8ZRdFgdmvSs7AAmZl7ZHL4yrzdKO3kKqtx8fW6NyZEE5GrU7I4GFWoSFtzC 7p0yKhN5x/63dL4p1yAJpdRDaMPYdMPxQ18oJRbYIBnKnRrchT3+iAEXQugjyvrwuC5y4sfuLMyTJ NdGMVASCakMHAm5Qgta8KfiNO3KsNXH1ca2aQVGqSPmvwJgW8Xs4WVB3qscvIAgAgzMWLT7pJN/GG j/erBAAcD9RuAWWz4r/3ut0NbHBSbNUGQTpHs0jTX+YeyUi7DW2djN9P8V9cjqYEXurV+gqiT46f7 LLAy3WTw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWrWx-00088q-O3; Tue, 11 Dec 2018 23:33:35 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWrTn-0004gh-BI for linux-arm-kernel@lists.infradead.org; Tue, 11 Dec 2018 23:30:29 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 22EA715AB; Tue, 11 Dec 2018 15:30:19 -0800 (PST) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7930B3F614; Tue, 11 Dec 2018 15:30:17 -0800 (PST) From: Dave Martin To: kvmarm@lists.cs.columbia.edu Subject: [RFC PATCH v3 15/24] KVM: arm64: Reject ioctl access to FPSIMD V-regs on SVE vcpus Date: Tue, 11 Dec 2018 23:28:52 +0000 Message-Id: <1544570941-7377-16-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1544570941-7377-1-git-send-email-Dave.Martin@arm.com> References: <1544570941-7377-1-git-send-email-Dave.Martin@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181211_153019_670983_0C181134 X-CRM114-Status: GOOD ( 16.47 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Okamoto Takayuki , Christoffer Dall , Ard Biesheuvel , Marc Zyngier , Catalin Marinas , Will Deacon , =?utf-8?q?Alex_Benn=C3=A9e?= , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP In order to avoid the pointless complexity of maintaining two ioctl register access views of the same data, this patch blocks ioctl access to the FPSIMD V-registers on vcpus that support SVE. This will make it more straightforward to add SVE register access support. Since SVE is an opt-in feature for userspace, this will not affect existing users. Signed-off-by: Dave Martin --- Changes since RFC v2: * New patch The initial code was split from "KVM: arm64/sve: Add SVE support to register access ioctl interface". However, some additional refactoring makes this change quite noisy: for ease of review, I decided it was best to keep the two parts of the change separate. * Move core_reg_offset_is_vreg() before validate_core_reg_id() (which now makes use of it). * Move rejection of KVM_REG_ARM_CORE view of the FPSIMD V-regs on SVE-enabled vcpus into validate_core_reg_id(), so that it can be applied everywhere appropriate instead of being open-coded. This requires vcpu to be pushed down into a few code paths (This is the noise alluded to above). --- arch/arm64/kvm/guest.c | 39 +++++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 0bf0ed3..e1ea73e 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -83,7 +83,13 @@ static int core_reg_size_from_offset(u64 off) return -EINVAL; } -static int validate_core_reg_id(u64 id) +static bool core_reg_offset_is_vreg(u64 off) +{ + return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) && + off < KVM_REG_ARM_CORE_REG(fp_regs.fpsr); +} + +static int validate_core_reg_id(const struct kvm_vcpu *vcpu, u64 id) { u64 off = core_reg_offset_from_id(id); int size = core_reg_size_from_offset(off); @@ -91,10 +97,18 @@ static int validate_core_reg_id(u64 id) if (size < 0) return size; - if (KVM_REG_SIZE(id) == size && IS_ALIGNED(off, size / sizeof(__u32))) - return 0; + if (KVM_REG_SIZE(id) != size || !IS_ALIGNED(off, size / sizeof(__u32))) + return -EINVAL; - return -EINVAL; + /* + * The KVM_REG_ARM64_SVE regs must be used instead of + * KVM_REG_ARM_CORE for accessing the FPSIMD V-registers on + * SVE-enabled vcpus: + */ + if (vcpu_has_sve(vcpu) && core_reg_offset_is_vreg(off)) + return -EINVAL; + + return 0; } static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) @@ -116,7 +130,7 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs) return -ENOENT; - if (validate_core_reg_id(reg->id)) + if (validate_core_reg_id(vcpu, reg->id)) return -EINVAL; if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id))) @@ -141,7 +155,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs) return -ENOENT; - if (validate_core_reg_id(reg->id)) + if (validate_core_reg_id(vcpu, reg->id)) return -EINVAL; if (KVM_REG_SIZE(reg->id) > sizeof(tmp)) @@ -194,7 +208,8 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) return -EINVAL; } -static int copy_core_reg_indices(u64 __user **uind) +static int copy_core_reg_indices(const struct kvm_vcpu *vcpu, + u64 __user **uind) { unsigned int i; int total = 0; @@ -228,7 +243,7 @@ static int copy_core_reg_indices(u64 __user **uind) break; } - if (validate_core_reg_id(id)) + if (validate_core_reg_id(vcpu, id)) continue; if (uind) { @@ -243,9 +258,9 @@ static int copy_core_reg_indices(u64 __user **uind) return total; } -static unsigned long num_core_regs(void) +static unsigned long num_core_regs(const struct kvm_vcpu *vcpu) { - return copy_core_reg_indices(NULL); + return copy_core_reg_indices(vcpu, NULL); } /** @@ -310,7 +325,7 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu) { unsigned long res = 0; - res += num_core_regs(); + res += num_core_regs(vcpu); res += kvm_arm_num_sys_reg_descs(vcpu); res += kvm_arm_get_fw_num_regs(vcpu); res += NUM_TIMER_REGS; @@ -327,7 +342,7 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) { int ret; - ret = copy_core_reg_indices(&uindices); + ret = copy_core_reg_indices(vcpu, &uindices); if (ret < 0) return ret;