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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44106C77B76 for ; Thu, 20 Apr 2023 14:16:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231948AbjDTOQT (ORCPT ); Thu, 20 Apr 2023 10:16:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230459AbjDTOQO (ORCPT ); Thu, 20 Apr 2023 10:16:14 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC4A240DB; Thu, 20 Apr 2023 07:16:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1682000173; x=1713536173; h=from:to:cc:subject:date:message-id; bh=Rwr5CeFQ61aTbP5d7pe753QwhuSBeTN+SBYWhcSkS7A=; b=DgFl3KMCb7fYydrRgGdD8MNogg+rmw2sQY545aQq7shV+Znvz+40w/dk G+aoSkUxilkHQ8t0yZcgqKWfjGqKwwEzoHeZTzjAcV5Zh2yu/jl55fPJI ptn3d15lon/TUBKZBiDFrzXbwYlip8FYEPdaroHLN78kksfr+ZcW3GO3i ShnZDeYSyl0jsRNZsZKyqRVErrJKmYPVdI01BPTdEorwMQFBr00w+889X ++B770+Hx7O1hRG/6YbQ+grKy7L1hCynUugz2lj13KzRo0ZjN+zyE6EZR NmLnA7aGzvFOqPB1B0itOHgiSNK7lszP30Vh1HadLexSGKzpwxv3jkUQR g==; X-IronPort-AV: E=McAfee;i="6600,9927,10686"; a="343217764" X-IronPort-AV: E=Sophos;i="5.99,212,1677571200"; d="scan'208";a="343217764" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Apr 2023 07:16:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10686"; a="816028785" X-IronPort-AV: E=Sophos;i="5.99,212,1677571200"; d="scan'208";a="816028785" Received: from arthur-vostro-3668.sh.intel.com ([10.238.200.53]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Apr 2023 07:15:57 -0700 From: Zeng Guang To: Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , H Peter Anvin , kvm@vger.kernel.org Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Gao Chao , Zeng Guang Subject: [PATCH 0/6] LASS KVM virtualization support Date: Thu, 20 Apr 2023 21:37:18 +0800 Message-Id: <20230420133724.11398-1-guang.zeng@intel.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Linear Address Space Separation (LASS)[1] is a new mechanism that enforces the same mode-based protections as paging, i.e. SMAP/SMEP but without traversing the paging structures. Because the protections enforced by LASS are applied before paging, "probes" by malicious software will provide no paging-based timing information. LASS works in long mode and partitions the 64-bit canonical linear address space into two halves: 1. Lower half (LA[63]=0) --> user space 2. Upper half (LA[63]=1) --> kernel space When LASS is enabled, a general protection #GP fault or a stack fault #SS will be generated if software accesses the address from the half in which it resides to another half, e.g., either from user space to upper half, or from kernel space to lower half. This protection applies to data access, code execution. This series add KVM LASS virtualization support. When platform has LASS capability, KVM requires to expose this feature to guest VM enumerated by CPUID.(EAX=07H.ECX=1):EAX.LASS[bit 6], and allow guest to enable it via CR4.LASS[bit 27] on demand. For instruction executed in the guest directly, hardware will perform the LASS violation check, while KVM also needs to apply LASS to instructions emulated by software and injects #GP or #SS fault to the guest. Following LASS voilations check will be taken on KVM emulation path. User-mode access to supervisor space address: LA[bit 63] && (CPL == 3) Supervisor-mode access to user space address: Instruction fetch: !LA[bit 63] && (CPL < 3) Data access: !LA[bit 63] && (CR4.SMAP==1) && ((RFLAGS.AC == 0 && CPL < 3) || Implicit supervisor access) We tested the basic function of LASS virtualization including LASS enumeration and enabling in non-root and nested environment. As current KVM unittest framework is not compatible to LASS rule that kernel should run in the upper half, we use kernel module and application test to verify LASS functionalities in guest instead. The data access related x86 emulator code is verified with forced emulation prefix (FEP) mechanism. Other test cases are working in progress. How to add tests for LASS in KUT or kselftest is still under investigation. [1] Intel Architecutre Instruction Set Extensions and Future Features Programming Reference: Chapter Linear Address Space Separation (LASS) https://cdrdv2.intel.com/v1/dl/getContent/671368 Zeng Guang (6): KVM: x86: Virtualize CR4.LASS KVM: VMX: Add new ops in kvm_x86_ops for LASS violation check KVM: x86: Add emulator helper for LASS violation check KVM: x86: LASS protection on KVM emulation when LASS enabled KVM: x86: Advertise LASS CPUID to user space KVM: x86: Set KVM LASS based on hardware capability arch/x86/include/asm/cpuid.h | 36 +++++++++++++++++++ arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 7 +++- arch/x86/kvm/cpuid.c | 8 +++-- arch/x86/kvm/emulate.c | 36 ++++++++++++++++--- arch/x86/kvm/kvm_emulate.h | 1 + arch/x86/kvm/vmx/nested.c | 3 ++ arch/x86/kvm/vmx/sgx.c | 2 ++ arch/x86/kvm/vmx/vmx.c | 58 ++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/vmx.h | 2 ++ arch/x86/kvm/x86.c | 9 +++++ arch/x86/kvm/x86.h | 2 ++ 12 files changed, 157 insertions(+), 8 deletions(-) -- 2.27.0