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 ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (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 AB4DDC4332F for ; Tue, 7 Nov 2023 08:05:45 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id 149CA60D33 for ; Tue, 7 Nov 2023 08:05:45 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id DE1B89867FE for ; Tue, 7 Nov 2023 08:05:44 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id C64F89867E8; Tue, 7 Nov 2023 08:05:44 +0000 (UTC) Mailing-List: contact virtio-comment-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id BBA8E9867EA for ; Tue, 7 Nov 2023 08:05:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: Hdmx52b3Ptytst6Uiw3Y5Q-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699344311; x=1699949111; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=u6t95Qag17M/YFz4xN8tPtid7yfQWmagZck/lyGlg/0=; b=TqIb57/4N/Z0iDMU2b6DbyWdNk+7XS/ZeX0HaZPh/EyPjPOPFEKaOEXdHGf0jaGF9p uFMaHo22xtez5jfGeu6UXx1AMdSD0bTCQEjRNV8hbWhvHOH1O/ylHMRmK+j/L1sleYz+ 7lUY/g6R+h4HGauj8rSdyiZjYasiBW1P0w1ZcY7s5yBfVsnFTFbZEcVIoEnyrOod0iRr ikmlneb5umvqhz4Wik3ptHIjs3BGvWP+Bijmgdfu4qeg722EV38XBu3PKt8jrXEDhxoz wlV5a21LvwpbRm0RUQSGhTgtT6rTmEFHeJ6/NA184gUtwAG0Kvf3PVcnkicqKEGa6kqY FLAA== X-Gm-Message-State: AOJu0YztmVZ5duYTR6LIZRXUXKV69Wj2ZWMl8kTDyZyO0wTTkLZUnbBA mWaf12ttCLlQyk8u/64MoW67xuBzjVrxtlXdlPsZgJ66o5MQWmURt9Uf37opEhIcGNmw0VVamV1 Cw0TFD1Ztx7inKDwl/Zu4yuQ15RB8zJl6xg== X-Received: by 2002:a7b:c5d7:0:b0:408:37aa:774a with SMTP id n23-20020a7bc5d7000000b0040837aa774amr2121269wmk.17.1699344311562; Tue, 07 Nov 2023 00:05:11 -0800 (PST) X-Google-Smtp-Source: AGHT+IFyOO0XMNLbJY+PKId48vD/V64Bmimi2sU9OFiLQ8ArUGCd7iFkaiQl064CRhHdSgenNThNpw== X-Received: by 2002:a7b:c5d7:0:b0:408:37aa:774a with SMTP id n23-20020a7bc5d7000000b0040837aa774amr2121241wmk.17.1699344311195; Tue, 07 Nov 2023 00:05:11 -0800 (PST) Date: Tue, 7 Nov 2023 03:05:04 -0500 From: "Michael S. Tsirkin" To: "Zhu, Lingshan" Cc: Jason Wang , Parav Pandit , "virtio-comment@lists.oasis-open.org" , "cohuck@redhat.com" , "sburla@marvell.com" , Shahaf Shuler , Maor Gottlieb , Yishai Hadas Message-ID: <20231107030205-mutt-send-email-mst@kernel.org> References: <20231107021917-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: Re: [virtio-comment] [PATCH v1 1/8] admin: Add theory of operation for device migration On Tue, Nov 07, 2023 at 03:57:29PM +0800, Zhu, Lingshan wrote: > > > On 11/7/2023 3:22 PM, Michael S. Tsirkin wrote: > > On Tue, Nov 07, 2023 at 12:05:12PM +0800, Jason Wang wrote: > > > > > > > One thing that you ignore is that, hypervisor can use what you > > > > > > > invented as a transport for VF, no? > > > > > > > > > > > > > No. by design, > > > > > It works like hypervisor traps the virito config and forwards it to admin > > > > > virtqueue and starts the device via device context. > > > > It needs more granular support than the management framework of device context. > > > It doesn't otherwise it is a design defect as you can't recover the > > > device context in the destination. > > > > > > Let me give you an example: > > > > > > 1) in the case of live migration, dst receive migration byte flows and > > > convert them into device context > > > 2) in the case of transporting, hypervisor traps virtio config and > > > convert them into the device context > > > > > > I don't see anything different in this case. Or can you give me an example? > > "trap virtio config" means "trap writes into virtio config" presumably? > > config can change itself without driver doing anything. Hypervisor > > can't trap it then. This is one of the problems with Lingshan's > > SUSPEND bit - what happens with these config changes in underspecified. > It should send a config interrupt and increase its generation. /me shrugs > By the way, is it buggy if a device suspend itself? > Is needs_reset better even not properly handled by virito driver NEEDS_RESET turned out not to be a great design. -- MST This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. 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