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 Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2898ACDB47E for ; Fri, 13 Oct 2023 10:28:51 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id B90D741D9F; Fri, 13 Oct 2023 10:28:50 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org B90D741D9F Authentication-Results: smtp4.osuosl.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=UjGqXHhG X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sdbF-DAhWgMo; Fri, 13 Oct 2023 10:28:48 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTPS id 185FF41DB2; Fri, 13 Oct 2023 10:28:48 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 185FF41DB2 Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id E2DD9C0071; Fri, 13 Oct 2023 10:28:47 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 64F3EC0032 for ; Fri, 13 Oct 2023 10:28:47 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 3DA28405D6 for ; Fri, 13 Oct 2023 10:28:47 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 3DA28405D6 Authentication-Results: smtp2.osuosl.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=UjGqXHhG X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9j2Y_1w3jPO2 for ; Fri, 13 Oct 2023 10:28:46 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.136]) by smtp2.osuosl.org (Postfix) with ESMTPS id 28BCC400CB for ; Fri, 13 Oct 2023 10:28:46 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 28BCC400CB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697192926; x=1728728926; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to; bh=/ji+HuuWrqaUKnBD5fajwGqzQmBqwfwkvoSu+zCpKPw=; b=UjGqXHhGpsrMwzwy0cERkRyl2rC2MpyXZXtIGPg4SvB+aEO1vFxNkmRQ 8Z04ucFst4K9LCAQSFmPL66l8hg5tu9v+bUXuzoWTXI4VJ7SOFmQNussZ 8t2soNOVWzvddYXFfnbeQ3gGqBS+yIIf4VWEpZPYYdC22tx3VeLMU8miQ 84Z/hhhUMeuJ4QQ2RsHNLESumhoIAPFOM2JaZt/c2W6EeoQRyP/o8a8Gg vTzfKJKBRSvcNxYi22iDgRggllOdPP0DwpQ78GTXpZA/6OLXBAh1N0NgC Z17rkrmMJ8ONhoAPqMIHhNgVNnmUIa7A56l58zSf9Rb+Y1IicDE0Ia9Yf A==; X-IronPort-AV: E=McAfee;i="6600,9927,10861"; a="364515209" X-IronPort-AV: E=Sophos;i="6.03,221,1694761200"; d="scan'208,217";a="364515209" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2023 03:28:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10861"; a="758453038" X-IronPort-AV: E=Sophos;i="6.03,221,1694761200"; d="scan'208,217";a="758453038" Received: from lingshan-mobl.ccr.corp.intel.com (HELO [10.93.29.0]) ([10.93.29.0]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2023 03:28:37 -0700 Message-ID: <840d4c6f-4150-4818-a66c-1dbe1474b4c6@intel.com> Date: Fri, 13 Oct 2023 18:28:34 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH vfio 10/11] vfio/virtio: Expose admin commands over virtio device Content-Language: en-US To: Jason Gunthorpe References: <20231010140849.GL3952@nvidia.com> <20231010105339-mutt-send-email-mst@kernel.org> <20231010111339-mutt-send-email-mst@kernel.org> <20231010155937.GN3952@nvidia.com> <20231011021454-mutt-send-email-mst@kernel.org> <20231012132749.GK3952@nvidia.com> From: "Zhu, Lingshan" In-Reply-To: <20231012132749.GK3952@nvidia.com> Cc: "kvm@vger.kernel.org" , "Michael S. Tsirkin" , Leon Romanovsky , "virtualization@lists.linux-foundation.org" , Christoph Hellwig , Jiri Pirko , Maor Gottlieb X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============6032283145338888533==" Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" This is a multi-part message in MIME format. --===============6032283145338888533== Content-Type: multipart/alternative; boundary="------------NqORYrha0EqGVvEB2iIKOt8n" Content-Language: en-US This is a multi-part message in MIME format. --------------NqORYrha0EqGVvEB2iIKOt8n Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/12/2023 9:27 PM, Jason Gunthorpe wrote: > On Thu, Oct 12, 2023 at 06:29:47PM +0800, Zhu, Lingshan wrote: > >> sorry for the late reply, we have discussed this for weeks in virtio mailing >> list. I have proposed a live migration solution which is a config space solution. > I'm sorry that can't be a serious proposal - config space can't do > DMA, it is not suitable. config space only controls the live migration process and config the related facilities. We don't use config space to transfer data. The new added registers work like queue_enable or features. For example, we use DMA to report dirty pages and MMIO to fetch the dirty data. I remember in another thread you said:"you can't use DMA for any migration flows" And I agree to that statement, so we use config space registers to control the flow. Thanks, Zhu Lingshan > > Jason --------------NqORYrha0EqGVvEB2iIKOt8n Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit

On 10/12/2023 9:27 PM, Jason Gunthorpe wrote:
On Thu, Oct 12, 2023 at 06:29:47PM +0800, Zhu, Lingshan wrote:


sorry for the late reply, we have discussed this for weeks in virtio mailing
list. I have proposed a live migration solution which is a config space solution.

I'm sorry that can't be a serious proposal - config space can't do
DMA, it is not suitable.
config space only controls the live migration process and config the related facilities.
We don't use config space to transfer data.

The new added registers work like queue_enable or features.

For example, we use DMA to report dirty pages and MMIO to fetch the dirty data.

I remember in another thread you said:"you can't use DMA for any migration flows"

And I agree to that statement, so we use config space registers to control the flow.

Thanks,
Zhu Lingshan
 

Jason

--------------NqORYrha0EqGVvEB2iIKOt8n-- --===============6032283145338888533== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization --===============6032283145338888533==--