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 C4A03EB64DC for ; Fri, 14 Jul 2023 22:02:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229819AbjGNWCm (ORCPT ); Fri, 14 Jul 2023 18:02:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229966AbjGNWCj (ORCPT ); Fri, 14 Jul 2023 18:02:39 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A37C71BF3 for ; Fri, 14 Jul 2023 15:02:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=fgAY7veGGJCbRAMMbGZOc0grcKb2j7RyXFUpzppk3bI=; b=bUUx3olRZMph1mbYBULy3tcBGa yVuwnMLkusxKRB5aElHF9v8LE4c5B1NsUQP1H4CVV8ydwGJBFAo7T//lx2WyIcElM5/DfM/FEZgSw 3GsErSOjrNHZHOKjE9y5BNn2kRA5LYVAVCT084KHQWN+fETr/h3/mtrK3xBKtLIU33Wofk2Hic9Vg z6A14nxA2a+tWcVM22LKs+46IFDOdJTIOK7Mokb8WpWJeJXLwgt+nY/gZFFRxwDIv+QLfZ98BWESN bfzKin4y3lx2Faw7Yu0loNW2LyGSsUEgzvZNBPpkgVXFKg9BrLZDYVdvc6Mxkvg+g+usjZA51BLB2 1gFtjF+w==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qKQrk-006OfH-2c; Fri, 14 Jul 2023 22:02:21 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 3FC593001FD; Sat, 15 Jul 2023 00:02:20 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 29DFE245CA115; Sat, 15 Jul 2023 00:02:20 +0200 (CEST) Date: Sat, 15 Jul 2023 00:02:20 +0200 From: Peter Zijlstra To: Arjan van de Ven Cc: "Wysocki, Rafael J" , Bruno Goncalves , x86@kernel.org, LKML Subject: Re: [6.5.0-rc1] unchecked MSR access error: RDMSR from 0xe2 at rIP: 0xffffffff87090227 (native_read_msr+0x7/0x40) (intel_idle_init_cstates_icpu) Message-ID: <20230714220220.GC3273303@hirez.programming.kicks-ass.net> References: <20230711112421.GI3062772@hirez.programming.kicks-ass.net> <20230711125557.GM3062772@hirez.programming.kicks-ass.net> <20230711132553.GN3062772@hirez.programming.kicks-ass.net> <0837a34c-f66e-aa04-d4a7-b032d3dbab7a@intel.com> <20230714211109.GC3275140@hirez.programming.kicks-ass.net> <6ce7c4d8-3320-7712-a562-a43224c2602b@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6ce7c4d8-3320-7712-a562-a43224c2602b@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 14, 2023 at 02:47:24PM -0700, Arjan van de Ven wrote: > > I still don't know why this needs to be in intel_idle. > > we can do a seperate idle driver; it'll still be x86 specific (since > idle really is arch specific)... and then the umwait parts of this > will be Intel specific.. as well any future idle methods .. and I'm > not sure the AMD folks would even want it used .... at which point it > ends up Intel specific fully and we now have 2 Intel idle drivers. I > don't see how that makes sense. intel-idle is huge, the last thing it needs is yet another little driver hidding inside it. Creating a new simple and small x86-guest cpuidle driver seems, well, simpler. And the whole umwait / mwaitx thing really isn't that hard, this is all indirect functions anyway. All that thing needs to do is amortize the VMEXIT cost.