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 D2E10C4332F for ; Wed, 12 Jan 2022 17:02:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355481AbiALRCD (ORCPT ); Wed, 12 Jan 2022 12:02:03 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:27260 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355435AbiALRBy (ORCPT ); Wed, 12 Jan 2022 12:01:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1642006913; 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=ZgYej9XbZ+Xa/X6Uh7UhuWNezHk2QG3G7eDzov+zY+E=; b=Hm48/Hgqx7gk4XU1yTc7c0Ex5yDysVAxZDNqEgmwBKzIHE3NoOew6GD/afpzOAclSvOeQF ceowJUEX/QTu5rM+yckZtQsGsTlklS3oNmMFhqD6XUFUmcez96aabd87ywJLKDhVBIxCbM rXFFPUWTfC3N9jbW7AXmVm3A6FehzyE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-590-J_5RRZwaN8maCVNhxIMYww-1; Wed, 12 Jan 2022 12:01:50 -0500 X-MC-Unique: J_5RRZwaN8maCVNhxIMYww-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 031F780574C; Wed, 12 Jan 2022 17:01:48 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.194.48]) by smtp.corp.redhat.com (Postfix) with ESMTP id E5C5A2B45F; Wed, 12 Jan 2022 17:01:45 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Maxim Levitsky , linux-kernel@vger.kernel.org Subject: [PATCH v3 4/5] KVM: nVMX: Implement evmcs_field_offset() suitable for handle_vmread() Date: Wed, 12 Jan 2022 18:01:33 +0100 Message-Id: <20220112170134.1904308-5-vkuznets@redhat.com> In-Reply-To: <20220112170134.1904308-1-vkuznets@redhat.com> References: <20220112170134.1904308-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In preparation to allowing reads from Enlightened VMCS from handle_vmread(), implement evmcs_field_offset() to get the correct read offset. get_evmcs_offset(), which is being used by KVM-on-Hyper-V, is almost what's needed but a few things need to be adjusted. First, WARN_ON() is unacceptable for handle_vmread() as any field can (in theory) be supplied by the guest and not all fields are defined in eVMCS v1. Second, we need to handle 'holes' in eVMCS (missing fields). It also sounds like a good idea to WARN_ON() if such fields are ever accessed by KVM-on-Hyper-V. Implement dedicated evmcs_field_offset() helper. No functional change intended. Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/vmx/evmcs.c | 3 +-- arch/x86/kvm/vmx/evmcs.h | 32 ++++++++++++++++++++++++-------- 2 files changed, 25 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c index a7ed30d5647a..87e3dc10edf4 100644 --- a/arch/x86/kvm/vmx/evmcs.c +++ b/arch/x86/kvm/vmx/evmcs.c @@ -12,8 +12,6 @@ DEFINE_STATIC_KEY_FALSE(enable_evmcs); -#if IS_ENABLED(CONFIG_HYPERV) - #define EVMCS1_OFFSET(x) offsetof(struct hv_enlightened_vmcs, x) #define EVMCS1_FIELD(number, name, clean_field)[ROL16(number, 6)] = \ {EVMCS1_OFFSET(name), clean_field} @@ -296,6 +294,7 @@ const struct evmcs_field vmcs_field_to_evmcs_1[] = { }; const unsigned int nr_evmcs_1_fields = ARRAY_SIZE(vmcs_field_to_evmcs_1); +#if IS_ENABLED(CONFIG_HYPERV) __init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf) { vmcs_conf->pin_based_exec_ctrl &= ~EVMCS1_UNSUPPORTED_PINCTRL; diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h index 3a461a32128b..9bc2521b159e 100644 --- a/arch/x86/kvm/vmx/evmcs.h +++ b/arch/x86/kvm/vmx/evmcs.h @@ -65,8 +65,6 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs); #define EVMCS1_UNSUPPORTED_VMENTRY_CTRL (VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL) #define EVMCS1_UNSUPPORTED_VMFUNC (VMX_VMFUNC_EPTP_SWITCHING) -#if IS_ENABLED(CONFIG_HYPERV) - struct evmcs_field { u16 offset; u16 clean_field; @@ -75,26 +73,44 @@ struct evmcs_field { extern const struct evmcs_field vmcs_field_to_evmcs_1[]; extern const unsigned int nr_evmcs_1_fields; -static __always_inline int get_evmcs_offset(unsigned long field, - u16 *clean_field) +static __always_inline int evmcs_field_offset(unsigned long field, + u16 *clean_field) { unsigned int index = ROL16(field, 6); const struct evmcs_field *evmcs_field; - if (unlikely(index >= nr_evmcs_1_fields)) { - WARN_ONCE(1, "KVM: accessing unsupported EVMCS field %lx\n", - field); + if (unlikely(index >= nr_evmcs_1_fields)) return -ENOENT; - } evmcs_field = &vmcs_field_to_evmcs_1[index]; + /* + * Use offset=0 to detect holes in eVMCS. This offset belongs to + * 'revision_id' but this field has no encoding and is supposed to + * be accessed directly. + */ + if (unlikely(!evmcs_field->offset)) + return -ENOENT; + if (clean_field) *clean_field = evmcs_field->clean_field; return evmcs_field->offset; } +#if IS_ENABLED(CONFIG_HYPERV) + +static __always_inline int get_evmcs_offset(unsigned long field, + u16 *clean_field) +{ + int offset = evmcs_field_offset(field, clean_field); + + WARN_ONCE(offset < 0, "KVM: accessing unsupported EVMCS field %lx\n", + field); + + return offset; +} + static __always_inline void evmcs_write64(unsigned long field, u64 value) { u16 clean_field; -- 2.34.1