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 17A81C25B6D for ; Wed, 25 Oct 2023 00:01:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344715AbjJYABe (ORCPT ); Tue, 24 Oct 2023 20:01:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344663AbjJYABa (ORCPT ); Tue, 24 Oct 2023 20:01:30 -0400 Received: from out-197.mta1.migadu.com (out-197.mta1.migadu.com [95.215.58.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D641910D0 for ; Tue, 24 Oct 2023 17:01:27 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1698192085; 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=gulJryeOiAII7rRti1FgpAMjLmQKWyqOB8guMGZkbTk=; b=LOm2g80fdK+Zk5MnmgUOQet8LgbtP/tQYKA6OMIXPTBEC7vrNUPmgB628GHUI7I8ZaII4i IVDHYLJXyoM8876962oTh9j+WU1EHNo9f+EOR5vArflelhg6qZzgZ6T5Ntt8db+kZ9N0zf gLQ6XHnz90rwmGJ9eyd1uB2fX6JeIWA= From: Oliver Upton To: Raghavendra Rao Ananta , Marc Zyngier Cc: Oliver Upton , Zenghui Yu , Jing Zhang , kvm@vger.kernel.org, Reiji Watanabe , Shaoqin Huang , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Suzuki K Poulose , kvmarm@lists.linux.dev, James Morse , Colton Lewis , Paolo Bonzini , Alexandru Elisei Subject: Re: [PATCH v8 00/13] KVM: arm64: PMU: Allow userspace to limit the number of PMCs on vCPU Date: Wed, 25 Oct 2023 00:01:12 +0000 Message-ID: <169819197647.2014901.5722928932912558103.b4-ty@linux.dev> In-Reply-To: <20231020214053.2144305-1-rananta@google.com> References: <20231020214053.2144305-1-rananta@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Oct 2023 21:40:40 +0000, Raghavendra Rao Ananta wrote: > The goal of this series is to allow userspace to limit the number > of PMU event counters on the vCPU. We need this to support migration > across systems that implement different numbers of counters. > > The number of PMU event counters is indicated in PMCR_EL0.N. > For a vCPU with PMUv3 configured, its value will be the same as > the current PE by default. Userspace can set PMCR_EL0.N for the > vCPU to any value even with the current KVM using KVM_SET_ONE_REG. > However, it is practically unsupported, as KVM resets PMCR_EL0.N > to the host value on vCPU reset and some KVM code uses the host > value to identify (un)implemented event counters on the vCPU. > > [...] I've applied this with Marc + I's fixes. I'm happy to toss any fixes on top of this series if folks spot issues. [01/13] KVM: arm64: PMU: Introduce helpers to set the guest's PMU https://git.kernel.org/kvmarm/kvmarm/c/1616ca6f3c10 [02/13] KVM: arm64: PMU: Set the default PMU for the guest before vCPU reset https://git.kernel.org/kvmarm/kvmarm/c/427733579744 [03/13] KVM: arm64: PMU: Add a helper to read a vCPU's PMCR_EL0 https://git.kernel.org/kvmarm/kvmarm/c/57fc267f1b5c [04/13] KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU https://git.kernel.org/kvmarm/kvmarm/c/4d20debf9ca1 [05/13] KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} https://git.kernel.org/kvmarm/kvmarm/c/a45f41d754e0 [06/13] KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run https://git.kernel.org/kvmarm/kvmarm/c/27131b199f9f [07/13] KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest https://git.kernel.org/kvmarm/kvmarm/c/ea9ca904d24f [08/13] tools: Import arm_pmuv3.h https://git.kernel.org/kvmarm/kvmarm/c/9f4b3273dfbe [09/13] KVM: selftests: aarch64: Introduce vpmu_counter_access test https://git.kernel.org/kvmarm/kvmarm/c/8d0aebe1ca2b [10/13] KVM: selftests: aarch64: vPMU register test for implemented counters https://git.kernel.org/kvmarm/kvmarm/c/ada1ae68262d [11/13] KVM: selftests: aarch64: vPMU register test for unimplemented counters https://git.kernel.org/kvmarm/kvmarm/c/e1cc87206348 [12/13] KVM: selftests: aarch64: vPMU test for validating user accesses https://git.kernel.org/kvmarm/kvmarm/c/62708be351fe -- Best, Oliver