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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 4E9D4C7618B for ; Wed, 24 Jul 2019 11:20:52 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id DA1592190F for ; Wed, 24 Jul 2019 11:20:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DA1592190F 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 435454A579; Wed, 24 Jul 2019 07:20:51 -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 VUkH0LB3wIrN; Wed, 24 Jul 2019 07:20:49 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7D7BF4A586; Wed, 24 Jul 2019 07:20:49 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4F4784A572 for ; Wed, 24 Jul 2019 07:20:48 -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 qenEyWIlmO8V for ; Wed, 24 Jul 2019 07:20:47 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id DD7464A562 for ; Wed, 24 Jul 2019 07:20:46 -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 7FBB8337; Wed, 24 Jul 2019 04:20:46 -0700 (PDT) Received: from [10.1.197.61] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DA6C13F71A; Wed, 24 Jul 2019 04:20:45 -0700 (PDT) Subject: Re: [PATCH 2/3] KVM: arm/arm64: vgic-its: Do not execute invalidate MSI-LPI translation cache on movi command To: Xiangyou Xie References: <20190724090437.49952-1-xiexiangyou@huawei.com> <20190724090437.49952-3-xiexiangyou@huawei.com> From: Marc Zyngier Openpgp: preference=signencrypt Autocrypt: addr=marc.zyngier@arm.com; prefer-encrypt=mutual; keydata= mQINBE6Jf0UBEADLCxpix34Ch3kQKA9SNlVQroj9aHAEzzl0+V8jrvT9a9GkK+FjBOIQz4KE g+3p+lqgJH4NfwPm9H5I5e3wa+Scz9wAqWLTT772Rqb6hf6kx0kKd0P2jGv79qXSmwru28vJ t9NNsmIhEYwS5eTfCbsZZDCnR31J6qxozsDHpCGLHlYym/VbC199Uq/pN5gH+5JHZyhyZiNW ozUCjMqC4eNW42nYVKZQfbj/k4W9xFfudFaFEhAf/Vb1r6F05eBP1uopuzNkAN7vqS8XcgQH qXI357YC4ToCbmqLue4HK9+2mtf7MTdHZYGZ939OfTlOGuxFW+bhtPQzsHiW7eNe0ew0+LaL 3wdNzT5abPBscqXWVGsZWCAzBmrZato+Pd2bSCDPLInZV0j+rjt7MWiSxEAEowue3IcZA++7 ifTDIscQdpeKT8hcL+9eHLgoSDH62SlubO/y8bB1hV8JjLW/jQpLnae0oz25h39ij4ijcp8N t5slf5DNRi1NLz5+iaaLg4gaM3ywVK2VEKdBTg+JTg3dfrb3DH7ctTQquyKun9IVY8AsxMc6 lxl4HxrpLX7HgF10685GG5fFla7R1RUnW5svgQhz6YVU33yJjk5lIIrrxKI/wLlhn066mtu1 DoD9TEAjwOmpa6ofV6rHeBPehUwMZEsLqlKfLsl0PpsJwov8TQARAQABtCNNYXJjIFp5bmdp ZXIgPG1hcmMuenluZ2llckBhcm0uY29tPokCTwQTAQIAOQIbAwYLCQgHAwIGFQgCCQoLBBYC AwECHgECF4AWIQSf1RxT4LVjGP2VnD0j0NC60T16QwUCXR3BUgAKCRAj0NC60T16Qyd/D/9s x0puxd3lI+jdLMEY8sTsNxw/+CZfyKaHtysasZlloLK7ftYhRUc63mMW2mrvgB1GEnXYIdj3 g6Qo4csoDuN+9EBmejh7SglM/h0evOtrY2V5QmZA/e/Pqfj0P3N/Eb5BiB3R4ptLtvKCTsqr 3womxCRqQY3IrMn1s2qfpmeNLUIfCUtgh8opzPtFuFJWVBzbzvhPEApZzMe9Vs1O2P8BQaay QXpbzHaKruthoLICRzS/3UCe0N/mBZQRKHrqhPwvjZdO0KMqjSsPqfukOJ8bl5jZxYk+G/3T 66Z4JUpZ7RkcrX7CvBfZqRo19WyWFfjGz79iVMJNIEkJvJBANbTSiWUC6IkP+zT/zWYzZPXx XRlrKWSBBqJrWQKZBwKOLsL62oQG7ARvpCG9rZ6hd5CLQtPI9dasgTwOIA1OW2mWzi20jDjD cGC9ifJiyWL8L/bgwyL3F/G0R1gxAfnRUknyzqfpLy5cSgwKCYrXOrRqgHoB+12HA/XQUG+k vKW8bbdVk5XZPc5ghdFIlza/pb1946SrIg1AsjaEMZqunh0G7oQhOWHKOd6fH0qg8NssMqQl jLfFiOlgEV2mnaz6XXQe/viXPwa4NCmdXqxeBDpJmrNMtbEbq+QUbgcwwle4Xx2/07ICkyZH +7RvbmZ/dM9cpzMAU53sLxSIVQT5lj23WLkCDQROiX9FARAAz/al0tgJaZ/eu0iI/xaPk3DK NIvr9SsKFe2hf3CVjxriHcRfoTfriycglUwtvKvhvB2Y8pQuWfLtP9Hx3H+YI5a78PO2tU1C JdY5Momd3/aJBuUFP5blbx6n+dLDepQhyQrAp2mVC3NIp4T48n4YxL4Og0MORytWNSeygISv Rordw7qDmEsa7wgFsLUIlhKmmV5VVv+wAOdYXdJ9S8n+XgrxSTgHj5f3QqkDtT0yG8NMLLmY kZpOwWoMumeqn/KppPY/uTIwbYTD56q1UirDDB5kDRL626qm63nF00ByyPY+6BXH22XD8smj f2eHw2szECG/lpD4knYjxROIctdC+gLRhz+Nlf8lEHmvjHgiErfgy/lOIf+AV9lvDF3bztjW M5oP2WGeR7VJfkxcXt4JPdyDIH6GBK7jbD7bFiXf6vMiFCrFeFo/bfa39veKUk7TRlnX13go gIZxqR6IvpkG0PxOu2RGJ7Aje/SjytQFa2NwNGCDe1bH89wm9mfDW3BuZF1o2+y+eVqkPZj0 mzfChEsiNIAY6KPDMVdInILYdTUAC5H26jj9CR4itBUcjE/tMll0n2wYRZ14Y/PM+UosfAhf YfN9t2096M9JebksnTbqp20keDMEBvc3KBkboEfoQLU08NDo7ncReitdLW2xICCnlkNIUQGS WlFVPcTQ2sMAEQEAAYkCHwQYAQIACQUCTol/RQIbDAAKCRAj0NC60T16QwsFD/9T4y30O0Wn MwIgcU8T2c2WwKbvmPbaU2LDqZebHdxQDemX65EZCv/NALmKdA22MVSbAaQeqsDD5KYbmCyC czilJ1i+tpZoJY5kJALHWWloI6Uyi2s1zAwlMktAZzgGMnI55Ifn0dAOK0p8oy7/KNGHNPwJ eHKzpHSRgysQ3S1t7VwU4mTFJtXQaBFMMXg8rItP5GdygrFB7yUbG6TnrXhpGkFBrQs9p+SK vCqRS3Gw+dquQ9QR+QGWciEBHwuSad5gu7QC9taN8kJQfup+nJL8VGtAKgGr1AgRx/a/V/QA ikDbt/0oIS/kxlIdcYJ01xuMrDXf1jFhmGZdocUoNJkgLb1iFAl5daV8MQOrqciG+6tnLeZK HY4xCBoigV7E8KwEE5yUfxBS0yRreNb+pjKtX6pSr1Z/dIo+td/sHfEHffaMUIRNvJlBeqaj BX7ZveskVFafmErkH7HC+7ErIaqoM4aOh/Z0qXbMEjFsWA5yVXvCoJWSHFImL9Bo6PbMGpI0 9eBrkNa1fd6RGcktrX6KNfGZ2POECmKGLTyDC8/kb180YpDJERN48S0QBa3Rvt06ozNgFgZF Wvu5Li5PpY/t/M7AAkLiVTtlhZnJWyEJrQi9O2nXTzlG1PeqGH2ahuRxn7txA5j5PHZEZdL1 Z46HaNmN2hZS/oJ69c1DI5Rcww== Organization: ARM Ltd Message-ID: Date: Wed, 24 Jul 2019 12:20:43 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190724090437.49952-3-xiexiangyou@huawei.com> Content-Language: en-US Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On 24/07/2019 10:04, Xiangyou Xie wrote: > It is not necessary to invalidate the lpi translation cache when the > virtual machine executes the movi instruction to adjust the affinity of > the interrupt. Irqbalance will adjust the interrupt affinity in a short > period of time to achieve the purpose of interrupting load balancing, > but this does not affect the contents of the lpi translation cache. What does irqbalance have to do with it? We're dealing with the GIC architecture here, not with userspace. If the guest issues a MOVI command to a RD where GICR_CTLR.EnableLPI is 0, and that we use an existing cached translation, we are going to make the interrupt pending for that RD. This is direct violation of the architecture, which says: "LPI support is disabled. Any doorbell interrupt generated as a result of a write to a virtual LPI register must be discarded, and any ITS translation requests or commands involving LPIs in this Redistributor are ignored." So the interrupt cannot be made pending. No IFs, no BUTs. If you really want to optimize it, check that the target RD is actually enabled and only invalidate in this particular case. Your guest would have to have a rate of MOVI that is comparable to that of the interrupts for it to show on any radar though... Thanks, M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm