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 A8FE0C4167B for ; Fri, 23 Dec 2022 19:34:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232242AbiLWTeb (ORCPT ); Fri, 23 Dec 2022 14:34:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230366AbiLWTeZ (ORCPT ); Fri, 23 Dec 2022 14:34:25 -0500 Received: from mail.zytor.com (unknown [IPv6:2607:7c80:54:3::138]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9185E2018E; Fri, 23 Dec 2022 11:34:24 -0800 (PST) Received: from [127.0.0.1] ([73.223.250.219]) (authenticated bits=0) by mail.zytor.com (8.17.1/8.17.1) with ESMTPSA id 2BNJY7kW3005320 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Fri, 23 Dec 2022 11:34:08 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 2BNJY7kW3005320 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2022120601; t=1671824048; bh=IrboZx5CPC/dL/EdCsJXRS0OtXozRdw6gy0xC4hc90I=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=R5pLy9wg3IEoVnGbPbdm89AwneJqiYGnORrjHZQGNU+Paj35segoutCkPgDjLEYEx ykh5cC1tDtHw4Q8U1Ww7NZ+8B9VuYfHGv/NrrMX5JbDR0Kx8TqRz8DSNygppgJPy/b wmLkB+wbiOEHzsRoqoupa8JUtS2oMhFtig5tQpMuV93UUB8yPV0kU5qbUEmPcbKqe1 Inf9JJBwsBUh+5q78j8dLNq2SSeDWKTe4zJphbTpISrDMawJNqV+B+2+WCNkj406RK Xrk1n55tRsZ/QxGMBE4kqkMcUPjs49vIP2ncJxGAAutBpLnDm1tkCCaTsvpXvCkc6G DDybFYu/EihVw== Date: Fri, 23 Dec 2022 11:34:05 -0800 From: "H. Peter Anvin" To: Peter Zijlstra , "Li, Xin3" CC: "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "kvm@vger.kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "andrew.cooper3@citrix.com" , "Christopherson,, Sean" , "pbonzini@redhat.com" , "Shankar, Ravi V" Subject: Re: [RFC PATCH 14/32] x86/fred: header file with FRED definitions User-Agent: K-9 Mail for Android In-Reply-To: References: <20221220063658.19271-1-xin3.li@intel.com> <20221220063658.19271-15-xin3.li@intel.com> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On December 22, 2022 5:03:57 AM PST, Peter Zijlstra wrote: >On Wed, Dec 21, 2022 at 02:58:06AM +0000, Li, Xin3 wrote: > >> > > +/* Flags above the CS selector (regs->csl) */ >> > > +#define FRED_CSL_ENABLE_NMI _BITUL(28) >> > > +#define FRED_CSL_ALLOW_SINGLE_STEP _BITUL(25) >> > > +#define FRED_CSL_INTERRUPT_SHADOW _BITUL(24) >> >=20 >> > What's the state of IBT WAIT-FOR-ENDBR vs this? That really should al= so get a >> > high CS bit=2E >>=20 >> FRED does provide more possibilities :) > >That's not an answer=2E IBT has a clear defect and FRED *should* fix it= =2E You are not wrong, of course=2E That being said, we have not wanted to hit= ch too many things to the FRED baseline, lest it ends up delayed for implem= entation/validation reasons=2E The important thing is that FRED *does* prov= ide the mechanism for addressing that even if it does not make the first im= plementation=2E