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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, 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 ED1F2C388F9 for ; Mon, 23 Nov 2020 13:46:10 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 78647206F1 for ; Mon, 23 Nov 2020 13:46:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="vVX4omis" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 78647206F1 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.34351.65346 (Exim 4.92) (envelope-from ) id 1khCAJ-0002CI-Bc; Mon, 23 Nov 2020 13:45:59 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 34351.65346; Mon, 23 Nov 2020 13:45:59 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1khCAJ-0002CB-6u; Mon, 23 Nov 2020 13:45:59 +0000 Received: by outflank-mailman (input) for mailman id 34351; Mon, 23 Nov 2020 13:45:58 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1khCAI-0002C4-R3 for xen-devel@lists.xenproject.org; Mon, 23 Nov 2020 13:45:58 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id fcb645b7-d493-414d-8ed5-da826e2edc67; Mon, 23 Nov 2020 13:45:58 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6277DAD19; Mon, 23 Nov 2020 13:45:57 +0000 (UTC) Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1khCAI-0002C4-R3 for xen-devel@lists.xenproject.org; Mon, 23 Nov 2020 13:45:58 +0000 X-Inumbo-ID: fcb645b7-d493-414d-8ed5-da826e2edc67 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id fcb645b7-d493-414d-8ed5-da826e2edc67; Mon, 23 Nov 2020 13:45:58 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1606139157; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w7uDOn4N0IoJ51us1LkK9OZYghwqQsMbEk0Oi9fZxmc=; b=vVX4omisYEgIILBK7CbJImhtB56Q0TRg2zdFwOd5W9a35SD3MCmc8tUfmQHZCCX6gHZVw8 1BRDnqx24cDcwiNY2Dn44KlU9EZc00YAKS2vyeFVjjmhrxvtsyH/t5X0Qsi/+vRbLF3Iul HKGyOPtTmLW6CgpA3rze81SEmbGnoM8= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6277DAD19; Mon, 23 Nov 2020 13:45:57 +0000 (UTC) Subject: [PATCH v3 6/7] x86: make guarding against straight-line speculation optional From: Jan Beulich To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , Wei Liu , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= References: <8e7d1472-dd37-8ed3-ec2f-ce954ea61dfd@suse.com> Message-ID: Date: Mon, 23 Nov 2020 14:45:56 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <8e7d1472-dd37-8ed3-ec2f-ce954ea61dfd@suse.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Put insertion of INT3 behind CONFIG_SPECULATIVE_HARDEN_BRANCH conditionals. Signed-off-by: Jan Beulich --- v3: New. --- a/xen/arch/x86/indirect-thunk.S +++ b/xen/arch/x86/indirect-thunk.S @@ -11,8 +11,10 @@ #include +#ifdef CONFIG_SPECULATIVE_HARDEN_BRANCH /* Don't transform the "ret" further down. */ .purgem ret +#endif .macro IND_THUNK_RETPOLINE reg:req call 2f @@ -45,7 +47,9 @@ ENTRY(__x86_indirect_thunk_\reg) __stringify(IND_THUNK_LFENCE \reg), X86_FEATURE_IND_THUNK_LFENCE, \ __stringify(IND_THUNK_JMP \reg), X86_FEATURE_IND_THUNK_JMP +#ifdef CONFIG_SPECULATIVE_HARDEN_BRANCH int3 /* Halt straight-line speculation */ +#endif .size __x86_indirect_thunk_\reg, . - __x86_indirect_thunk_\reg .type __x86_indirect_thunk_\reg, @function --- a/xen/include/asm-x86/asm-defns.h +++ b/xen/include/asm-x86/asm-defns.h @@ -45,6 +45,8 @@ INDIRECT_BRANCH jmp \arg .endm +#ifdef CONFIG_SPECULATIVE_HARDEN_BRANCH + /* * To guard against speculation past RET, insert a breakpoint insn * immediately after them. @@ -60,3 +62,5 @@ .word \operand .endif .endm + +#endif