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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 6A706C433DB for ; Fri, 15 Jan 2021 16:43:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1FA3422262 for ; Fri, 15 Jan 2021 16:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726475AbhAOQn0 (ORCPT ); Fri, 15 Jan 2021 11:43:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:38508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726151AbhAOQn0 (ORCPT ); Fri, 15 Jan 2021 11:43:26 -0500 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 9B538221FE; Fri, 15 Jan 2021 16:42:45 +0000 (UTC) Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1l0SBP-007o67-EU; Fri, 15 Jan 2021 16:42:43 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 15 Jan 2021 16:42:38 +0000 From: Marc Zyngier To: Auger Eric Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Suzuki K Poulose , kernel-team@android.com, James Morse , Alexandru Elisei , Julien Thierry Subject: Re: [PATCH 6/6] KVM: arm64: Upgrade PMU support to ARMv8.4 In-Reply-To: References: <20210114105633.2558739-1-maz@kernel.org> <20210114105633.2558739-7-maz@kernel.org> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <28dab4367d6ced5a7d7cbc80ee77f68d@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: eric.auger@redhat.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, suzuki.poulose@arm.com, kernel-team@android.com, james.morse@arm.com, alexandru.elisei@arm.com, julien.thierry.kdev@gmail.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Eric, On 2021-01-15 14:01, Auger Eric wrote: > Hi Marc, > > On 1/14/21 11:56 AM, Marc Zyngier wrote: >> Upgrading the PMU code from ARMv8.1 to ARMv8.4 turns out to be >> pretty easy. All that is required is support for PMMIR_EL1, which >> is read-only, and for which returning 0 is a valid option. >> >> Let's just do that and adjust what we return to the guest. >> >> Signed-off-by: Marc Zyngier >> --- >> arch/arm64/kvm/sys_regs.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c >> index 8f79ec1fffa7..2f4ecbd2abfb 100644 >> --- a/arch/arm64/kvm/sys_regs.c >> +++ b/arch/arm64/kvm/sys_regs.c >> @@ -1051,10 +1051,10 @@ static u64 read_id_reg(const struct kvm_vcpu >> *vcpu, >> /* Limit debug to ARMv8.0 */ >> val &= ~FEATURE(ID_AA64DFR0_DEBUGVER); >> val |= FIELD_PREP(FEATURE(ID_AA64DFR0_DEBUGVER), 6); >> - /* Limit guests to PMUv3 for ARMv8.1 */ >> + /* Limit guests to PMUv3 for ARMv8.4 */ >> val = cpuid_feature_cap_perfmon_field(val, >> ID_AA64DFR0_PMUVER_SHIFT, >> - kvm_vcpu_has_pmu(vcpu) ? ID_AA64DFR0_PMUVER_8_1 : 0); >> + kvm_vcpu_has_pmu(vcpu) ? ID_AA64DFR0_PMUVER_8_4 : 0); >> break; >> case SYS_ID_DFR0_EL1: >> /* Limit guests to PMUv3 for ARMv8.1 */ > what about the debug version in aarch32 state. Is it on purpose that > you > leave it as 8_1? That's a good point. There is also the fact that we keep reporting STALL_SLOT as a valid event even in PMCEID0_EL1 despite PMMIR_EL1.SLOTS always reporting 0. I'll fix that and resend something next week. Thanks, M. -- Jazz is not dead. It just smells funny...