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[209.132.183.28]) by mx.google.com with ESMTPS id h90si931784qtd.353.2019.05.13.08.25.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 May 2019 08:25:26 -0700 (PDT) Received-SPF: pass (google.com: domain of armbru@redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; Authentication-Results: mx.google.com; spf=pass (google.com: domain of armbru@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=armbru@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2690F59451; Mon, 13 May 2019 15:25:26 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-28.ams2.redhat.com [10.36.116.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C59666A490; Mon, 13 May 2019 15:25:25 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 42ADE11385E4; Mon, 13 May 2019 17:25:23 +0200 (CEST) From: Markus Armbruster To: Andrew Jones Cc: qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org, richard.henderson@linaro.org, abologna@redhat.com, alex.bennee@linaro.org, Dave.Martin@arm.com Subject: Re: [Qemu-devel] [PATCH 11/13] target/arm/cpu64: max cpu: Introduce sve-vls-map References: <20190512083624.8916-1-drjones@redhat.com> <20190512083624.8916-12-drjones@redhat.com> Date: Mon, 13 May 2019 17:25:23 +0200 In-Reply-To: <20190512083624.8916-12-drjones@redhat.com> (Andrew Jones's message of "Sun, 12 May 2019 10:36:22 +0200") Message-ID: <875zqefkbg.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 13 May 2019 15:25:26 +0000 (UTC) X-TUID: tmtmTq4wJEx1 Andrew Jones writes: > Introduce another cpu property to control SVE vector lengths, > sve-vls-map, which allows the user to explicitly select the > set of vector lengths the guest can use. The map must conform > to QEMU's limits and architectural constraints, checked when > the property is set. Inconsistencies with sve-max-vq are also > checked. The bit number of a set bit in the map represents the > allowed vector length in number of quadwords. > > Note, as the map is implemented with a single 64-bit word we > currently only support up to 8192-bit vectors. As QEMU and > KVM only support up to 2048-bit vectors then this sufficient > now, and probably for some time. Extending the bitmap beyond > a single word will likely require changing the property to > a string and adding yet another parser to QEMU. > > Signed-off-by: Andrew Jones Please add an example of how the new property should be used on the command line to your commit message. I'd ask for a documentation update as well if we had any to update. 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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 13202C04AA7 for ; Mon, 13 May 2019 15:32:09 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DCF0E2084A for ; Mon, 13 May 2019 15:32:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DCF0E2084A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:59167 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hQCvw-0004TT-26 for qemu-devel@archiver.kernel.org; Mon, 13 May 2019 11:32:08 -0400 Received: from eggs.gnu.org ([209.51.188.92]:50999) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hQCud-0003hZ-CV for qemu-devel@nongnu.org; Mon, 13 May 2019 11:30:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hQCpU-0002WJ-5c for qemu-devel@nongnu.org; Mon, 13 May 2019 11:25:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48166) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hQCpT-0002Uu-0m; Mon, 13 May 2019 11:25:27 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2690F59451; Mon, 13 May 2019 15:25:26 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-28.ams2.redhat.com [10.36.116.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C59666A490; Mon, 13 May 2019 15:25:25 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 42ADE11385E4; Mon, 13 May 2019 17:25:23 +0200 (CEST) From: Markus Armbruster To: Andrew Jones References: <20190512083624.8916-1-drjones@redhat.com> <20190512083624.8916-12-drjones@redhat.com> Date: Mon, 13 May 2019 17:25:23 +0200 In-Reply-To: <20190512083624.8916-12-drjones@redhat.com> (Andrew Jones's message of "Sun, 12 May 2019 10:36:22 +0200") Message-ID: <875zqefkbg.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 13 May 2019 15:25:26 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 11/13] target/arm/cpu64: max cpu: Introduce sve-vls-map X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, richard.henderson@linaro.org, qemu-devel@nongnu.org, abologna@redhat.com, qemu-arm@nongnu.org, alex.bennee@linaro.org, Dave.Martin@arm.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Andrew Jones writes: > Introduce another cpu property to control SVE vector lengths, > sve-vls-map, which allows the user to explicitly select the > set of vector lengths the guest can use. The map must conform > to QEMU's limits and architectural constraints, checked when > the property is set. Inconsistencies with sve-max-vq are also > checked. The bit number of a set bit in the map represents the > allowed vector length in number of quadwords. > > Note, as the map is implemented with a single 64-bit word we > currently only support up to 8192-bit vectors. As QEMU and > KVM only support up to 2048-bit vectors then this sufficient > now, and probably for some time. Extending the bitmap beyond > a single word will likely require changing the property to > a string and adding yet another parser to QEMU. > > Signed-off-by: Andrew Jones Please add an example of how the new property should be used on the command line to your commit message. I'd ask for a documentation update as well if we had any to update.