From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (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 1E3813B47D7; Wed, 11 Mar 2026 07:56:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773215772; cv=none; b=NRp2wvzcRf2vTEQt46pceHk9WRD5qZSBjME4WzU2kK2GPCByy0TuUTrARBKVAQiGDSZWx9Gqa/vl3pJu9d33Ix304RcobVIyXrEoF0rKbo9dWWzPscUpjsBGXTramkslLWsOUdVdEm+veyuT987u3nQQQXtABXtioLiULy8StVo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773215772; c=relaxed/simple; bh=5tJw/N/Q4TfAKMwbURztKDMvsFfpdCgyjfGiBO4m4XE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cCAbh/225Zi4/p3tfXZGXFDeOXas3Nv+KRT75fJtdDXYFpBeYhLfUeYyDA/7nbKlXUPkiXl/+Eg1f05ga85Jut2KF5rVpqov0RK4WgzL9nrDcyOEcM9pv9gQDRi9+DfxdZZOhkul021zpxLj6ZrO5PWf0BbY1Hmyw3AWCfC6gNg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=GItixpSO; arc=none smtp.client-ip=192.198.163.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="GItixpSO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1773215769; x=1804751769; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5tJw/N/Q4TfAKMwbURztKDMvsFfpdCgyjfGiBO4m4XE=; b=GItixpSOEA5jfwmSvSJIc+lCrdetUWap5KQVf6oMnsYT/o1LBQjsNZNN 26RE5Qb3Hi/FrIO9FIzLYpqb/u0qvm8o/yO0Fz7cz4Ye8Hwaup5V+GOCQ dN2Y9cRXsVw/G2m682bu7tQQKf/ZhcKd6EbxO7owXsUahQLrcZXtvxXyM KCWcUxnaiS0kPoUa3RYd6LZVgTCDc9BgvK7/6JRRE08U2E4AjcXjJ6gon tetPgODnjPDurUmL3RUosk4uKcPqYgeE97WeixzlHoqyf+Ue7ELF/PvpO X57AvKUS3nGICR6VG4mDka2wESWpf9zTdaHs1dJBON1y2kZ95KMz50hTK A==; X-CSE-ConnectionGUID: NtZzrELIQV64745ccXnSoQ== X-CSE-MsgGUID: wxlSLaPUREmkTDpnvJWnig== X-IronPort-AV: E=McAfee;i="6800,10657,11725"; a="73298913" X-IronPort-AV: E=Sophos;i="6.23,113,1770624000"; d="scan'208";a="73298913" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Mar 2026 00:56:08 -0700 X-CSE-ConnectionGUID: rdEoMP+xTMG2BjSYin8Fkw== X-CSE-MsgGUID: 6PfwFjJRSbWjRgj2zyGoNw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,113,1770624000"; d="scan'208";a="225081266" Received: from spr.sh.intel.com ([10.112.229.196]) by fmviesa005.fm.intel.com with ESMTP; 11 Mar 2026 00:56:04 -0700 From: Dapeng Mi To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Ian Rogers , Adrian Hunter , Alexander Shishkin , Andi Kleen , Eranian Stephane Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Dapeng Mi , Zide Chen , Falcon Thomas , Xudong Hao , Dapeng Mi Subject: [PATCH 2/2] perf/x86: Update cap_user_rdpmc base on rdpmc user disable state Date: Wed, 11 Mar 2026 15:52:01 +0800 Message-Id: <20260311075201.2951073-2-dapeng1.mi@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260311075201.2951073-1-dapeng1.mi@linux.intel.com> References: <20260311075201.2951073-1-dapeng1.mi@linux.intel.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit After introducing the RDPMC user disable feature, user-space RDPMC may return 0 instead of the actual event count. This creates an inconsistency with cap_user_rdpmc, where cap_user_rdpmc is set, but user-space RDPMC only returns 0. To accurately represent the user-space RDPMC capability, update cap_user_rdpmc based on the RDPMC user disable state. If RDPMC user disable is enabled, cap_user_rdpmc is set to false, allowing user-space programs to fall back to the read() syscall to obtain the real event count. Fixes: 59af95e028d4 ("perf/x86/intel: Add support for rdpmc user disable feature") Signed-off-by: Dapeng Mi --- arch/x86/events/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 03ce1bc7ef2e..0266a11d7ec9 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2807,6 +2807,9 @@ void arch_perf_update_userpage(struct perf_event *event, userpg->cap_user_time_zero = 0; userpg->cap_user_rdpmc = !!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT); + if (x86_pmu_has_rdpmc_user_disable(event->pmu) && + event->hw.config & ARCH_PERFMON_EVENTSEL_RDPMC_USER_DISABLE) + userpg->cap_user_rdpmc = 0; userpg->pmc_width = x86_pmu.cntval_bits; if (!using_native_sched_clock() || !sched_clock_stable()) -- 2.34.1