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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9EFCCC31E44 for ; Fri, 14 Jun 2019 12:08:38 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 1CCD4208CA for ; Fri, 14 Jun 2019 12:08:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1CCD4208CA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 54CFC4A483; Fri, 14 Jun 2019 08:08:37 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ltESMsca6GaI; Fri, 14 Jun 2019 08:08:36 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 31B8D4A4FD; Fri, 14 Jun 2019 08:08:36 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id BC3074A4A4 for ; Fri, 14 Jun 2019 08:08:35 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eW1V8cB3D46e for ; Fri, 14 Jun 2019 08:08:34 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 657544A483 for ; Fri, 14 Jun 2019 08:08:34 -0400 (EDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E0D2F2B; Fri, 14 Jun 2019 05:08:33 -0700 (PDT) Received: from [10.1.196.93] (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ECDC73F246; Fri, 14 Jun 2019 05:08:32 -0700 (PDT) Subject: Re: [PATCH v9 5/5] KVM: arm/arm64: support chained PMU counters To: andrew.murray@arm.com, christoffer.dall@arm.com, marc.zyngier@arm.com References: <20190612190450.7085-1-andrew.murray@arm.com> <20190612190450.7085-6-andrew.murray@arm.com> From: Suzuki K Poulose Message-ID: <3586de02-c64b-a9cd-1397-7e844a119625@arm.com> Date: Fri, 14 Jun 2019 13:08:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190612190450.7085-6-andrew.murray@arm.com> Content-Language: en-US Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On 12/06/2019 20:04, Andrew Murray wrote: > ARMv8 provides support for chained PMU counters, where an event type > of 0x001E is set for odd-numbered counters, the event counter will > increment by one for each overflow of the preceding even-numbered > counter. Let's emulate this in KVM by creating a 64 bit perf counter > when a user chains two emulated counters together. > > For chained events we only support generating an overflow interrupt > on the high counter. We use the attributes of the low counter to > determine the attributes of the perf event. > > Suggested-by: Marc Zyngier > Signed-off-by: Andrew Murray > Reviewed-by: Julien Thierry Reviewed-by: Suzuki K Poulose _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm