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=-15.8 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 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 50752C433EF for ; Mon, 6 Sep 2021 09:30:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DA9A61027 for ; Mon, 6 Sep 2021 09:30:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241319AbhIFJbN (ORCPT ); Mon, 6 Sep 2021 05:31:13 -0400 Received: from mail.skyhub.de ([5.9.137.197]:54084 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241313AbhIFJbJ (ORCPT ); Mon, 6 Sep 2021 05:31:09 -0400 Received: from zn.tnic (p200300ec2f0c2400e3336e9341833586.dip0.t-ipconnect.de [IPv6:2003:ec:2f0c:2400:e333:6e93:4183:3586]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id D96501EC04D1; Mon, 6 Sep 2021 11:30:02 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1630920603; h=from:from:reply-to:subject:subject: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=n1HSM8YrKqN1A8cBHayWCuJLrO98T8taynt/2Ecj/p4=; b=khLOXp/6KvfYyqQj1w2mTd9JUhUeg6l9ESMQubY/wvdTH4hAHhq3J18qt6hX7gtKrXepD5 5gBoIKzSE7Sib3p5MMAu8MZwcU2fvOlqJjNKai2voOLD7S2bcX4vMZ9rUu9J+CWydi5IdF 3xspFkUYNO6ClUsgns5A9XD5/dn7UU4= Date: Mon, 6 Sep 2021 11:30:01 +0200 From: Borislav Petkov To: Hao Peng Cc: tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org, Pawan Gupta Subject: Re: [PATCH] x86/tsx: clear RTM and HLE when MSR_IA32_TSX_CTRL is not supported Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 06, 2021 at 10:46:05AM +0800, Hao Peng wrote: > If hypervisor does not support MSR_IA32_TSX_CTRL, but guest supports > RTM and HLE features, it will affect TAA mitigation. > > Signed-off-by: Peng Hao > --- > arch/x86/kernel/cpu/tsx.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/x86/kernel/cpu/tsx.c b/arch/x86/kernel/cpu/tsx.c > index 9c7a5f049292..5e852c14fef2 100644 > --- a/arch/x86/kernel/cpu/tsx.c > +++ b/arch/x86/kernel/cpu/tsx.c > @@ -122,6 +122,13 @@ void __init tsx_init(void) > > if (!tsx_ctrl_is_supported()) { > tsx_ctrl_state = TSX_CTRL_NOT_SUPPORTED; > + > + /* If hypervisor does not support MSR_IA32_TSX_CTRL emulation, > + * but guest supports RTM and HLE features, it will affect TAA > + * （tsx_async_abort）mitigation. > + */ > + setup_clear_cpu_cap(X86_FEATURE_RTM); > + setup_clear_cpu_cap(X86_FEATURE_HLE); > return; > } How does that even happen - the hypervisor does not support the MSR but "guest supports" TSX features?! I guess the guest is detecting it wrong. What hypervisor, what guest, how do I reproduce? Please give full details. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette