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 0584BC433EF for ; Fri, 4 Mar 2022 13:42:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236609AbiCDNnE (ORCPT ); Fri, 4 Mar 2022 08:43:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237225AbiCDNmz (ORCPT ); Fri, 4 Mar 2022 08:42:55 -0500 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 A62A91B8BC3; Fri, 4 Mar 2022 05:42:04 -0800 (PST) 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=y9PpE0gkDy9J4jeFuVca7c+WURC8tyGMPwoneuqmxJo=; b=i2dMqtCBRJbiz7rFAWzNKCr52E philOHD1okKyQDRyMeL9Gcwmh4Yi/19FrTp81UNuP21poIVa16/x/QwNAnqN5zZuLNN2lD9iEd+H0 H/kgTxQumAnsf+qpSKxGwfc703k1iBKK+v5m8TYQ3UIQTCZWsmntCYK9JUTd6KBA0HZYUs1LrDww9 PlUK0tV2WHFMz6w9UqyucqAcgWOHdzvlYJ3kizKztQkQvFKsj6tHyR57QHsegm8adXNYHJMFMK1LV h+7YpME0R03XHQWQsJobOR8JTFuAcj6zSzfOV4E9yYDHk6bsKu0OskAiAzoT+ebET1PLREB6jXyBx LLlRHYRA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nQ8Bk-00FCcj-A2; Fri, 04 Mar 2022 13:41:44 +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) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 8ADFC3001EA; Fri, 4 Mar 2022 14:41:42 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7550C201A4139; Fri, 4 Mar 2022 14:41:42 +0100 (CET) Date: Fri, 4 Mar 2022 14:41:42 +0100 From: Peter Zijlstra To: Adrian Hunter Cc: Alexander Shishkin , Arnaldo Carvalho de Melo , Jiri Olsa , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, kvm@vger.kernel.org, H Peter Anvin , Mathieu Poirier , Suzuki K Poulose , Leo Yan Subject: Re: [PATCH V2 03/11] perf/x86: Add support for TSC in nanoseconds as a perf event clock Message-ID: References: <20220214110914.268126-1-adrian.hunter@intel.com> <20220214110914.268126-4-adrian.hunter@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220214110914.268126-4-adrian.hunter@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 14, 2022 at 01:09:06PM +0200, Adrian Hunter wrote: > Currently, when Intel PT is used within a VM guest, it is not possible to > make use of TSC because perf clock is subject to paravirtualization. Yeah, so how much of that still makes sense, or ever did? AFAIK the whole pv_clock thing is utter crazy. Should we not fix that instead?