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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 9D3A6C10F0E for ; Thu, 18 Apr 2019 16:10:44 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6AF4D20693 for ; Thu, 18 Apr 2019 16:10:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Cnh2kWC+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6AF4D20693 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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=Q/73Fc1m2SiFev2d8GISFj45Bodkd4Fa7VtOspUZZsA=; b=Cnh2kWC+V8dixIg0hEs8hzDSsQ 3/0rnCWW7uEKaXYUX5NhfSGHbKnvbJnSVvc89iBhYKSDDe9wW1fo+zeLX6miXOAEhqS8KIeNUxCp+ 6ul0QpW2HaiQwMldL+0Nyc853kdtE3g1q94TnKTKB6gzMKIG5ozTarYlmE2lBw86k9MB71kPjJkX0 CH0tDmXlg0BEymvWw9O/UnuU/LO7zEoYs+c5k+450uCiBuCoCRHOQxe3g7dZYv2rkMAxCkQlG5iLP fvAAcHPnGdEmQEvX+W0MidNifyjtYX3HxgtFdQXsNV3VqNb37dvHI/Eq1zRNT8GWId6Fmk1UQs+Xo SbQ3GilA==; 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 1hH9cS-0001uH-3S; Thu, 18 Apr 2019 16:10:36 +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 1hH9aR-0006N0-9N for linux-arm-kernel@lists.infradead.org; Thu, 18 Apr 2019 16:08:33 +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 3D07D169E; Thu, 18 Apr 2019 09:08:31 -0700 (PDT) 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 F09903F5AF; Thu, 18 Apr 2019 09:08:28 -0700 (PDT) From: Dave Martin To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v2 14/14] KVM: arm64: Clarify access behaviour for out-of-range SVE register slice IDs Date: Thu, 18 Apr 2019 17:07:11 +0100 Message-Id: <1555603631-8107-15-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1555603631-8107-1-git-send-email-Dave.Martin@arm.com> References: <1555603631-8107-1-git-send-email-Dave.Martin@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190418_090831_400178_D6578E92 X-CRM114-Status: GOOD ( 11.80 ) 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 , Andrew Jones , Zhang Lei , Julien Grall , =?UTF-8?q?Alex=20Benn=C3=A9e?= , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org The existing documentation for which SVE register slice IDs are considered out-of-range, and what happens when userspace tries to access them, is cryptic. This patch rewords the text with the aim of making it a bit easier to understand. No functional change. Suggested-by: Andrew Jones Signed-off-by: Dave Martin Reviewed-by: Andrew Jones --- Documentation/virtual/kvm/api.txt | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 818ac97..e410a9f 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2159,8 +2159,9 @@ arm64 SVE registers have the following bit patterns: 0x6050 0000 0015 060 FFR bits[256*slice + 255 : 256*slice] 0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register -Access to slices beyond the maximum vector length configured for the -vcpu (i.e., where 16 * slice >= max_vq (**)) will fail with ENOENT. +Access to register IDs where 2048 * slice >= 128 * max_vq will fail with +ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit +quadwords: see (**) below. These registers are only accessible on vcpus for which SVE is enabled. See KVM_ARM_VCPU_INIT for details. -- 2.1.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel