From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0917733EC for ; Mon, 16 Jan 2023 15:57:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80C39C433EF; Mon, 16 Jan 2023 15:57:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673884675; bh=/tp09Mprw1lIGcAX+snDZSpQYhuyWsel8eUaqvMOAwg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OgRFQHvtUpabj/ciYaBC5/Jj3e0218Xbfu6zA8ccvmc3ov4jLckP/siMxyQB4lDvP mKMuFpTejIBJdgetqLUZip5MM8SaHN39hiKQPQexP+iLOOHiUHY7j/zdOQjAOs+L/l GwfuxWcD1cVnRZB7ohC5qBQyIhOBq0DLcbu8IODM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Peter Newman , "Borislav Petkov (AMD)" , Reinette Chatre , Babu Moger Subject: [PATCH 6.1 096/183] x86/resctrl: Fix event counts regression in reused RMIDs Date: Mon, 16 Jan 2023 16:50:19 +0100 Message-Id: <20230116154807.457630188@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154803.321528435@linuxfoundation.org> References: <20230116154803.321528435@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Peter Newman commit 2a81160d29d65b5876ab3f824fda99ae0219f05e upstream. 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 Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Tested-by: Babu Moger Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20221220164132.443083-1-peternewman@google.com Signed-off-by: Greg Kroah-Hartman --- 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) { -- 2.39.0