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=-12.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 3392AC433FE for ; Thu, 10 Dec 2020 04:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02F3B23A02 for ; Thu, 10 Dec 2020 04:04:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732216AbgLJEEy (ORCPT ); Wed, 9 Dec 2020 23:04:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:55343 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731933AbgLJEEv (ORCPT ); Wed, 9 Dec 2020 23:04:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607572999; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ep/ZiwecWipeqk42V6c9PjyxWhVrZXaXr/UgV2fCnYY=; b=jUrAtZ1CPjriXmQQqEYE0LTNunMmk/UqBewk/0DPiiQYOJrNalv1kM0qiyo2gj0bd0fSie 2pm5WgO/Tpq+2WkuZoLK6oAvTYUGRHI/BxkU0ZBbdg7FqEBIVUiwv5QNERA5F+12iOIff3 5N/kIA/wMUx36u2D52rhU5cht7balcs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-512-3ir88J8zN1aW0_fCiv20MQ-1; Wed, 09 Dec 2020 23:03:15 -0500 X-MC-Unique: 3ir88J8zN1aW0_fCiv20MQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 18F32107ACF6; Thu, 10 Dec 2020 04:03:14 +0000 (UTC) Received: from [10.72.13.187] (ovpn-13-187.pek2.redhat.com [10.72.13.187]) by smtp.corp.redhat.com (Postfix) with ESMTP id C52E75D6A1; Thu, 10 Dec 2020 04:03:04 +0000 (UTC) Subject: Re: [PATCH v3 05/19] vdpa_sim: remove the limit of IOTLB entries To: Stefano Garzarella Cc: virtualization@lists.linux-foundation.org, Stefan Hajnoczi , "Michael S. Tsirkin" , Oren Duer , Laurent Vivier , linux-kernel@vger.kernel.org, Max Gurtovoy , Shahaf Shuler , Eli Cohen References: <20201203170511.216407-1-sgarzare@redhat.com> <20201203170511.216407-6-sgarzare@redhat.com> <20201209105829.6l6ie7xqp2eycds6@steredhat> From: Jason Wang Message-ID: <0333484d-7fa1-fc88-7e22-14492e994b72@redhat.com> Date: Thu, 10 Dec 2020 12:03:03 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201209105829.6l6ie7xqp2eycds6@steredhat> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/12/9 下午6:58, Stefano Garzarella wrote: > On Mon, Dec 07, 2020 at 12:00:07PM +0800, Jason Wang wrote: >> >> On 2020/12/4 上午1:04, Stefano Garzarella wrote: >>> The simulated devices can support multiple queues, so this limit >>> should be defined according to the number of queues supported by >>> the device. >>> >>> Since we are in a simulator, let's simply remove that limit. >>> >>> Suggested-by: Jason Wang >>> Acked-by: Jason Wang >>> Signed-off-by: Stefano Garzarella >> >> >> Rethink about this, since simulator can be used by VM, so the >> allocation is actually guest trigger-able when vIOMMU is enabled. >> >> This means we need a limit somehow, (e.g I remember swiotlb is about >> 64MB by default). Or having a module parameter for this. >> >> Btw, have you met any issue when using 2048, I guess it can happen >> when we run several processes in parallel? >> > > No, I didn't try with the limit. > This came from the reviews to Max's patches. > > Anyway I can add a module parameter to control that limit, do you > think is better to set a limit per queue (the parameter per number of > queues), or just a value for the entire device? Per-device should be ok. Thanks > > Thanks, > Stefano >