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 B085AC4332F for ; Wed, 14 Dec 2022 16:09:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238751AbiLNQJW (ORCPT ); Wed, 14 Dec 2022 11:09:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238407AbiLNQJT (ORCPT ); Wed, 14 Dec 2022 11:09:19 -0500 Received: from mail-wr1-x449.google.com (mail-wr1-x449.google.com [IPv6:2a00:1450:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A39D7F57 for ; Wed, 14 Dec 2022 08:09:18 -0800 (PST) Received: by mail-wr1-x449.google.com with SMTP id r17-20020adfb1d1000000b002421ae7fd46so39026wra.10 for ; Wed, 14 Dec 2022 08:09:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=w7oQvbAJgsoOmtULmkMdeiEDs6Dmo2nAnuZLG7TfGBQ=; b=QW6ivnixs8SD8vSnGu+DMuMjtIS7ZkExXQk539lwR4AMJNJHfYG9V14bXHHRE4BM2x IMFtpP8XdWZw6ORRVL4yOc01HJ9DQiobnNl5roxjCFv2p5K6LB5MB1LTmTpTg+dzUTBV fNSc6beGhwYN9tsX4WUs7Ve+5sNq4BlbH07KAPyl0ImelUqXnF6/FjUs229HMBv7KPs/ IANBlGz1vBDFB83lvgQdAohKVSFH1N3lC/gB8oqf5EcMW2MNe6Lzd6tz5SX76hDOdjHp CA1UihAbnMDBCgSazwFa08vByCZc+JhgEI2XYATBGJTGiNYEZiYq9fhYfH+6Jm/c9nvq O+mg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=w7oQvbAJgsoOmtULmkMdeiEDs6Dmo2nAnuZLG7TfGBQ=; b=Im1PKDgFbgBoSBl4ZOFoRBjF+Xvn5JyqyeBEuLganrGDnvbLjASm9+MX/MbOsr1sng 4orGEuk+nuTLSYvU/DWDFX9ICqCN2jAt5nq5YB49aSdWGQNJFrYStdmeb1etc995lTNr aiYoDrQpgHkJuh+oVoLcA8ijdHDmQIQ7G7vCP9FIj6pWsAXO5rbwxF2Y/72Bjsxf4Dl/ 9BSaMtxLTisNfKwSay8X4P8vRCcE/10Jrga9VPJ3fTkGMdv9CTHuEHy3I+/8Y6Xl6Dpn eSPyp8VqCP2ee/fbsJ4WRVzUDYq0ywUmBUrH6TNpyGjSFTHtRQ/FVKaKovOdEdHH9ZWl zluA== X-Gm-Message-State: ANoB5pnuNEpHx9zMeSwPFSv071l6+R4Q93q0uauE/M26GTs8h3VTtU4p LeG/ph5NaN9mcTugZauyJIUmorjXL9kfxg0fPw== X-Google-Smtp-Source: AA0mqf43qeFw+3iEb4uhwvQLKYNs1BD3vSG++gWcPlhWszLGKl2mVI6Nncj7tdfgMdko/oDbEidyknZ/V4o1vPw6+A== X-Received: from peternewman-vh.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:30cc]) (user=peternewman job=sendgmr) by 2002:a7b:ce85:0:b0:3d1:f143:c062 with SMTP id q5-20020a7bce85000000b003d1f143c062mr225183wmj.128.1671034157185; Wed, 14 Dec 2022 08:09:17 -0800 (PST) Date: Wed, 14 Dec 2022 17:08:55 +0100 Mime-Version: 1.0 X-Mailer: git-send-email 2.39.0.rc1.256.g54fd8350bd-goog Message-ID: <20221214160856.2164207-1-peternewman@google.com> Subject: [PATCH v2 1/2] x86/resctrl: Fix event counts regression in reused RMIDs From: Peter Newman To: reinette.chatre@intel.com, fenghua.yu@intel.com Cc: Babu.Moger@amd.com, bp@alien8.de, dave.hansen@linux.intel.com, eranian@google.com, hpa@zytor.com, james.morse@arm.com, linux-kernel@vger.kernel.org, mingo@redhat.com, quic_jiles@quicinc.com, tan.shaopeng@fujitsu.com, tglx@linutronix.de, x86@kernel.org, Peter Newman Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When creating a new monitoring group, the RMID allocated for it may have been used by a group which was previously removed. In this case, the hardware counters will have non-zero values which should be deducted from what is reported in the new group's counts. resctrl_arch_reset_rmid() initializes the prev_msr value for counters to 0, causing the initial count to be charged to the new group. Resurrect __rmid_read() and use it to initialize prev_msr correctly. Unlike before, __rmid_read() checks for error bits in the MSR read so that callers don't need to. Fixes: 1d81d15db39c ("x86/resctrl: Move mbm_overflow_count() into resctrl_arch_rmid_read()") Signed-off-by: Peter Newman --- arch/x86/kernel/cpu/resctrl/monitor.c | 49 ++++++++++++++++++--------- 1 file changed, 33 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index efe0c30d3a12..77538abeb72a 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -146,6 +146,30 @@ static inline struct rmid_entry *__rmid_entry(u32 rmid) return entry; } +static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val) +{ + u64 msr_val; + + /* + * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured + * with a valid event code for supported resource type and the bits + * IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID, + * IA32_QM_CTR.data (bits 61:0) reports the monitored data. + * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62) + * are error bits. + */ + wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid); + rdmsrl(MSR_IA32_QM_CTR, msr_val); + + if (msr_val & RMID_VAL_ERROR) + return -EIO; + if (msr_val & RMID_VAL_UNAVAIL) + return -EINVAL; + + *val = msr_val; + return 0; +} + static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_domain *hw_dom, u32 rmid, enum resctrl_event_id eventid) @@ -172,8 +196,12 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, struct arch_mbm_state *am; am = get_arch_mbm_state(hw_dom, rmid, eventid); - if (am) + if (am) { memset(am, 0, sizeof(*am)); + + /* Record any initial, non-zero count value. */ + __rmid_read(rmid, eventid, &am->prev_msr); + } } static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width) @@ -191,25 +219,14 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); struct arch_mbm_state *am; u64 msr_val, chunks; + int ret; if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask)) return -EINVAL; - /* - * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured - * with a valid event code for supported resource type and the bits - * IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID, - * IA32_QM_CTR.data (bits 61:0) reports the monitored data. - * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62) - * are error bits. - */ - wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid); - rdmsrl(MSR_IA32_QM_CTR, msr_val); - - if (msr_val & RMID_VAL_ERROR) - return -EIO; - if (msr_val & RMID_VAL_UNAVAIL) - return -EINVAL; + ret = __rmid_read(rmid, eventid, &msr_val); + if (ret) + return ret; am = get_arch_mbm_state(hw_dom, rmid, eventid); if (am) { base-commit: 830b3c68c1fb1e9176028d02ef86f3cf76aa2476 -- 2.39.0.rc1.256.g54fd8350bd-goog