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 22892C761AF for ; Mon, 3 Apr 2023 20:04:25 +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 9963841A2D for ; Mon, 3 Apr 2023 20:04:20 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id D31AF9867BA for ; Mon, 3 Apr 2023 20:04:19 +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 DADD39863F0; Mon, 3 Apr 2023 20:04:18 +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 D9CA49863E6 for ; Mon, 3 Apr 2023 20:02:48 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: QJSVuAAQNre2IbHSHDyI7w-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680552166; 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=62TyVBhAZtEAEIhi/uD8oEUdD4eh+DskgPJR/z/GnuQ=; b=0j0mQZEF7HIs2TjpES+gHfw3/7uCNZZ1RHA/Ekr9wFRiFtAyBk3sMRfDQi8UB+SMoT AArJaw1BCLd1EX80++moj0Q/ORs2ZoJvlonnjV1NAQQ1OJtnTkAyaqoOfEICHTEd6b+I O5a5G0vUbzHCxJCABAKZ4P3lpi+pektgbMSzHgZApTEcqprIZuql8zULyjMJPYhPVJg0 1Kg4QLrtKRuRRi/y5gzs9tQragWXdG9Mkmwp2XaGE4Z5V1puNYM6G0p8ZqozPLl+C9Qv Ivd3TBOu43n1dDNpbQLIqv7YoulkPR85eO3FkrjgkWb6DxedaMS+uycwAAMWxFZD4v1r NLpQ== X-Gm-Message-State: AAQBX9cBD7N/oMSmcOJSD+F8VVSwlSzRzIS3I6tBSim0KmardE0N+YuU 5cLEW8FPkGSbELgkYtzGV2LZ1BlK1RwBGBkChVERz+QYZ55WCWqb2ZsyO2GSPjxFgKxNwEOEK1h ydQPaiuKay3jBPIwGvV+o5AxoEAvqkZNBvg== X-Received: by 2002:a05:6402:31e1:b0:4fb:5291:13bb with SMTP id dy1-20020a05640231e100b004fb529113bbmr315911edb.39.1680552165861; Mon, 03 Apr 2023 13:02:45 -0700 (PDT) X-Google-Smtp-Source: AKy350Z5IdT/oVyozjbSXcpVzBy7KhRKJUoEUPAnTpKtWk3O/850ABI9erW9uJmY9RS7gbsw3R+fUA== X-Received: by 2002:a05:6402:31e1:b0:4fb:5291:13bb with SMTP id dy1-20020a05640231e100b004fb529113bbmr315886edb.39.1680552165537; Mon, 03 Apr 2023 13:02:45 -0700 (PDT) Date: Mon, 3 Apr 2023 16:02:39 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: Stefan Hajnoczi , "virtio-dev@lists.oasis-open.org" , "cohuck@redhat.com" , "virtio-comment@lists.oasis-open.org" , Shahaf Shuler Message-ID: <20230403155310-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230403144523.GC302168@fedora> <46a0db06-f922-2a8a-acf0-cf7e453a2945@nvidia.com> <20230403134407-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 00/11] Introduce transitional mmr pci device On Mon, Apr 03, 2023 at 07:48:56PM +0000, Parav Pandit wrote: > > OK but supporting them with a passthrough driver such as vfio does not seem > > that important. > Not sure on what basis you assert it. > I clarified in the cover letter that these are the user level requirements to support transitional and non-transitional devices both via single vfio subsystem. And what is so wrong with vdpa? Really I don't see how the virtio spec needs to accomodate specific partitioning between linux modules, be it vdpa or vfio. Way beyond the scope of the driver. But anyway, my main point is about DMA. On the one hand you are asking for a VQ based management interface because it saves money. On the other you are saying DMA operations take extremely long to the point where they are unusable in the boot sequence. So what is it? Was admin vq a mistake and we should do memory mapped? I know Jason really wanted that, and it makes a bunch of things easier. Or is legacy emulation doable over a vq and latency is not a concern, and the real reason is because it makes you push out a host driver with a bit less effort? I just do not see how these claims do not contradict each other. -- 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. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/ 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 E4E2BC76196 for ; Mon, 3 Apr 2023 20:04:19 +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 24202335C1 for ; Mon, 3 Apr 2023 20:04:19 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id EC982986418 for ; Mon, 3 Apr 2023 20:04:18 +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 D9DB49863E4; Mon, 3 Apr 2023 20:04:18 +0000 (UTC) Mailing-List: contact virtio-dev-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 E13A79863E5 for ; Mon, 3 Apr 2023 20:02:49 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 1HnYehblOiKgeN9HGxy81g-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680552166; 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=62TyVBhAZtEAEIhi/uD8oEUdD4eh+DskgPJR/z/GnuQ=; b=tzLoveqthTFt/XorrsrqC4Hcz0Lqeek9sUuw7v3eQD0ClXUkpAeWNbEH1u5V4gLnlH ARzJkvDDD559T9K2fPk8WbDRLZcKMPJZoXLCQiYI9IyAHupvPsvAzgwPpa73Gk9xWU7t VF5N0e4s+xCNAYmCkK+uzOu121YCTGfGMcGyJLG0iMIaWSvBZPsyMOqnVqqw5tRWap9I DWvOWo4KnHxQZll5ejIgDoCO6bQIJb2G2UDkjf9VgJ80gSlHAJn3SNowiue4r0oYmEXA 3K+Luj7tEhP1YtgDgGAfNo1HpXTNcUBDcth3hxwS+hMqOPsCPoDnqRgARexv5+IyrytO P4qw== X-Gm-Message-State: AAQBX9fLR1mtKe1GjQMTgVLQrX1JB6JQbriiT23508+Sg3sUDOayCeWo 3KUSFXMIExgz+E+YywA7Qvasi+jOgz5OdapyLL1Y6xOTilzC/n/r3BiLALjpQe47oXsku6WGtXd PpIEn1jb/e92LnNwVj8KrOKqxWPL1 X-Received: by 2002:a05:6402:31e1:b0:4fb:5291:13bb with SMTP id dy1-20020a05640231e100b004fb529113bbmr315914edb.39.1680552165862; Mon, 03 Apr 2023 13:02:45 -0700 (PDT) X-Google-Smtp-Source: AKy350Z5IdT/oVyozjbSXcpVzBy7KhRKJUoEUPAnTpKtWk3O/850ABI9erW9uJmY9RS7gbsw3R+fUA== X-Received: by 2002:a05:6402:31e1:b0:4fb:5291:13bb with SMTP id dy1-20020a05640231e100b004fb529113bbmr315886edb.39.1680552165537; Mon, 03 Apr 2023 13:02:45 -0700 (PDT) Date: Mon, 3 Apr 2023 16:02:39 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: Stefan Hajnoczi , "virtio-dev@lists.oasis-open.org" , "cohuck@redhat.com" , "virtio-comment@lists.oasis-open.org" , Shahaf Shuler Message-ID: <20230403155310-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230403144523.GC302168@fedora> <46a0db06-f922-2a8a-acf0-cf7e453a2945@nvidia.com> <20230403134407-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: [virtio-dev] Re: [virtio-comment] [PATCH 00/11] Introduce transitional mmr pci device On Mon, Apr 03, 2023 at 07:48:56PM +0000, Parav Pandit wrote: > > OK but supporting them with a passthrough driver such as vfio does not seem > > that important. > Not sure on what basis you assert it. > I clarified in the cover letter that these are the user level requirements to support transitional and non-transitional devices both via single vfio subsystem. And what is so wrong with vdpa? Really I don't see how the virtio spec needs to accomodate specific partitioning between linux modules, be it vdpa or vfio. Way beyond the scope of the driver. But anyway, my main point is about DMA. On the one hand you are asking for a VQ based management interface because it saves money. On the other you are saying DMA operations take extremely long to the point where they are unusable in the boot sequence. So what is it? Was admin vq a mistake and we should do memory mapped? I know Jason really wanted that, and it makes a bunch of things easier. Or is legacy emulation doable over a vq and latency is not a concern, and the real reason is because it makes you push out a host driver with a bit less effort? I just do not see how these claims do not contradict each other. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org