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,NICE_REPLY_A,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 33888C2D0E4 for ; Fri, 27 Nov 2020 10:56:43 +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 8AA7420853 for ; Fri, 27 Nov 2020 10:56:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="uPyiaRJY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8AA7420853 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.39151.71943 (Exim 4.92) (envelope-from ) id 1kibQT-0000ZQ-1Q; Fri, 27 Nov 2020 10:56:29 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 39151.71943; Fri, 27 Nov 2020 10:56:29 +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 1kibQS-0000ZJ-Tn; Fri, 27 Nov 2020 10:56:28 +0000 Received: by outflank-mailman (input) for mailman id 39151; Fri, 27 Nov 2020 10:56:27 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kibQR-0000ZD-LN for xen-devel@lists.xenproject.org; Fri, 27 Nov 2020 10:56:27 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 55f058ed-6de4-4b20-9e8a-0ceddf9b3824; Fri, 27 Nov 2020 10:56:25 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 77EEEAD7C; Fri, 27 Nov 2020 10:56:24 +0000 (UTC) Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kibQR-0000ZD-LN for xen-devel@lists.xenproject.org; Fri, 27 Nov 2020 10:56:27 +0000 X-Inumbo-ID: 55f058ed-6de4-4b20-9e8a-0ceddf9b3824 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 55f058ed-6de4-4b20-9e8a-0ceddf9b3824; Fri, 27 Nov 2020 10:56:25 +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=1606474584; 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=GJiGZRoGdo1CBYHWTG9rexMadMVBWHmssa+Ae+8gdGg=; b=uPyiaRJY2ts86APmhdGOk+UZ5iAfSeglbwg/zf3hdT2Lz3azuMmFfAN9rlLC/98qDALP8Z az2wvSmsEB8NF4pFjQIJsxgkCiItyUhbvyG9LVKUvnr+3RqaxZDXtHorV9EWAzNGd+pEIW QuO0fH57fd04E0EXJqNbpSzwWtZO0tk= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 77EEEAD7C; Fri, 27 Nov 2020 10:56:24 +0000 (UTC) Subject: Re: [PATCH] x86/msr: don't inject #GP when trying to read FEATURE_CONTROL To: Roger Pau Monne Cc: Andrew Cooper , Wei Liu , xen-devel@lists.xenproject.org References: <20201127104614.71933-1-roger.pau@citrix.com> From: Jan Beulich Message-ID: Date: Fri, 27 Nov 2020 11:56:25 +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: <20201127104614.71933-1-roger.pau@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit On 27.11.2020 11:46, Roger Pau Monne wrote: > Windows 10 will triple fault if #GP is injected when attempting to > read the FEATURE_CONTROL MSR on Intel or compatible hardware. Fix this > by injecting a #GP only when the vendor doesn't support the MSR, even > if there are no features to expose. > > Fixes: 39ab598c50a2 ('x86/pv: allow reading FEATURE_CONTROL MSR') > Signed-off-by: Roger Pau Monné In principle Acked-by: Jan Beulich However, iirc it was Andrew who had suggested the conditional you now replace, so I'd like to wait for him to voice a view. > --- a/xen/arch/x86/msr.c > +++ b/xen/arch/x86/msr.c > @@ -176,7 +176,7 @@ int guest_rdmsr(struct vcpu *v, uint32_t msr, uint64_t *val) > switch ( msr ) > { > case MSR_IA32_FEATURE_CONTROL: > - if ( !cp->basic.vmx && !vmce_has_lmce(v) ) > + if ( !(cp->x86_vendor & (X86_VENDOR_INTEL | X86_VENDOR_CENTAUR)) ) What about Shanghai? init_shanghai() calling init_intel_cacheinfo() suggests to me it's at least as Intel-like as Centaur/VIA. Jan