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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 B49B4C433F5 for ; Mon, 20 Sep 2021 12:22:12 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 3325D610A0 for ; Mon, 20 Sep 2021 12:22:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3325D610A0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id ACB234B0B4; Mon, 20 Sep 2021 08:22:11 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pJcQ4x1Fe29X; Mon, 20 Sep 2021 08:22:10 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 28D444B0B3; Mon, 20 Sep 2021 08:22:10 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id F28994B089 for ; Mon, 20 Sep 2021 08:22:08 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Waul+BbjoCU9 for ; Mon, 20 Sep 2021 08:22:08 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id D74844ACC9 for ; Mon, 20 Sep 2021 08:22:07 -0400 (EDT) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CD81460F9D; Mon, 20 Sep 2021 12:22:06 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mSIJA-00BkwX-Th; Mon, 20 Sep 2021 13:22:04 +0100 Date: Mon, 20 Sep 2021 13:22:04 +0100 Message-ID: <87tuifv3mb.wl-maz@kernel.org> From: Marc Zyngier To: Paolo Bonzini Subject: Re: [PATCH v2 00/13] perf: KVM: Fix, optimize, and clean up callbacks In-Reply-To: <662e93f9-e858-689d-d203-742731ecad2c@redhat.com> References: <20210828003558.713983-1-seanjc@google.com> <20210828201336.GD4353@worktop.programming.kicks-ass.net> <662e93f9-e858-689d-d203-742731ecad2c@redhat.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: pbonzini@redhat.com, peterz@infradead.org, seanjc@google.com, mingo@redhat.com, acme@kernel.org, will@kernel.org, mark.rutland@arm.com, catalin.marinas@arm.com, guoren@kernel.org, nickhu@andestech.com, green.hu@gmail.com, deanbo422@gmail.com, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, tglx@linutronix.de, bp@alien8.de, x86@kernel.org, boris.ostrovsky@oracle.com, jgross@suse.com, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, hpa@zytor.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, sstabellini@kernel.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-csky@vger.kernel.org, linux-riscv@lists.infradead.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org, artem.kashkanov@intel.com, like.xu.linux@gmail.com, lingsha n.zhu@intel.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: Wanpeng Li , kvm@vger.kernel.org, Peter Zijlstra , Catalin Marinas , Guo Ren , "H. Peter Anvin" , linux-riscv@lists.infradead.org, Vincent Chen , Jiri Olsa , Boris Ostrovsky , Stefano Stabellini , xen-devel@lists.xenproject.org, Will Deacon , Joerg Roedel , x86@kernel.org, linux-csky@vger.kernel.org, kvmarm@lists.cs.columbia.edu, Alexander Shishkin , Ingo Molnar , Like Xu , Albert Ou , Zhu Lingshan , Arnaldo Carvalho de Melo , Borislav Petkov , Greentime Hu , Paul Walmsley , Namhyung Kim , Thomas Gleixner , Artem Kashkanov , linux-arm-kernel@lists.infradead.org, Jim Mattson , Juergen Gross , Nick Hu , Sean Christopherson , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Palmer Dabbelt , Vitaly Kuznetsov X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Mon, 20 Sep 2021 13:05:25 +0100, Paolo Bonzini wrote: > > On 17/09/21 09:28, Peter Zijlstra wrote: > >> In theory, I like the idea of burying intel_pt inside x86 (and even in > >> Intel+VMX code for the most part), but the actual implementation is a > >> bit gross. Because of the whole "KVM can be a module" thing, > > > > ARGH!! we should really fix that. I've heard other archs have made much > > better choices here. > > I think that's only ARM, and even then it is only because of > limitations of the hardware which mostly apply only if VHE is not in > use. > > If anything, it's ARM that should support module build in VHE mode > (Linux would still need to know whether it will be running at EL1 or > EL2, but KVM's functionality is as self-contained as on x86 in the VHE > case). I don't see this happening anytime soon. At least not before we declare the arm64 single kernel image policy to be obsolete. M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm