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 19B63C7619A for ; Wed, 12 Apr 2023 05:12:17 +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 672DA3250 for ; Wed, 12 Apr 2023 05:12:16 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 5CD0F986549 for ; Wed, 12 Apr 2023 05:12:16 +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 51F10986509; Wed, 12 Apr 2023 05:12:16 +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 40A4F98650E for ; Wed, 12 Apr 2023 05:12:11 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: bxvIQwruNrunkCo_onRVcg-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681276328; 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=e/d3A4gx6awjnCS+UqmFyZ2zuplRG02Yk/eSwjUAJo8=; b=zarAndEj4b/PG1FDS3/sxOIpRSbIzCQV4gRArElIzUJI7dgJtY/do9sSHXLULX2QQP /AxvgjbTbHiiymOF7yYnUDknJA+IAKJuRAo21GhE2d1JCadqYyxO+t9j9SXSr0ZCa/tg 6y7pJjpzH09pyzaEuxVYuLSq7dmkz0vBWbZDAlfC8XUi0KYBCS0SNxQU898D6xXRSydA DJb+1DdN3oqHuoBjXS7PKvA8eQj8GSsmnE0sTKKW5pn4pcathBoYN3UOK9+CIoLMvudg jmWpd0/Qucs2RFoawmjVV1qCn5wd+jDOf94vKfOt05/D2tQXhZFVVTUSJxvONSu7aGVq EpEg== X-Gm-Message-State: AAQBX9eIWz8xktPJzM14h4tq065pbvWcVSm6LUEo+kxeHydDipuLTeWb jisx6ijpmwouaiK2m/Eq4uWCco21Q9EE4uZ9xhsw2vZ0rwGR++CThw8w/NFecyuBvlLUjW0vZdA I+jxTybnKyGnbFNm9P+pUYU+Woor6 X-Received: by 2002:a7b:cb45:0:b0:3ed:2eb5:c2dd with SMTP id v5-20020a7bcb45000000b003ed2eb5c2ddmr8492750wmj.39.1681276328105; Tue, 11 Apr 2023 22:12:08 -0700 (PDT) X-Google-Smtp-Source: AKy350bXTUapFTahVvq7aao4ki/GmR2Qf4y9Q9fdL7WZoCtVpOI5drrVDODleCRvW/uGp80Wj33cCg== X-Received: by 2002:a7b:cb45:0:b0:3ed:2eb5:c2dd with SMTP id v5-20020a7bcb45000000b003ed2eb5c2ddmr8492739wmj.39.1681276327825; Tue, 11 Apr 2023 22:12:07 -0700 (PDT) Date: Wed, 12 Apr 2023 01:12:04 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: "virtio-dev@lists.oasis-open.org" , "cohuck@redhat.com" , "virtio-comment@lists.oasis-open.org" , Shahaf Shuler Message-ID: <20230412010437-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230412004331-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: [PATCH 00/11] Introduce transitional mmr pci device On Wed, Apr 12, 2023 at 04:52:09AM +0000, Parav Pandit wrote: > > > From: Michael S. Tsirkin > > Sent: Wednesday, April 12, 2023 12:48 AM > > > Here is a counter proposal: > > > > #define VIRTIO_NET_F_LEGACY_HEADER 52 /* Use the legacy 10 byte > > header for all packets */ > > > > > > Yes, sorry to say, you need to emulate legacy pci in software. > > > > With notification hacks, and reset hacks, and legacy interrupt hacks, and > > writeable mac ... this thing best belongs in vdpa anyway. > > What? I don't follow. > Suddenly you attribute everything as hack with least explanation. > Again hacks is not a bad thing but it's an attempt at reusing things in unexpected ways. New issue I found today: - if guest disables MSI-X host can not disable MSI-X. need some other channel to notify device about this. Old issues we discussed before today: - reset needs some special handling because real hardware can not guarantee returning 0 on the 1st read - if guest writes into mac, reusing host mac (which is RO) will not work, need extra registers - something about notification makes you want to poke at modern notification register? which of course is its own can of worms with VIRTIO_F_NOTIFICATION_DATA changing the format completely. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org 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 134C6C77B6E for ; Wed, 12 Apr 2023 05:12:12 +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 5348A44545 for ; Wed, 12 Apr 2023 05:12:11 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 4C76E986520 for ; Wed, 12 Apr 2023 05:12:11 +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 43BE9986509; Wed, 12 Apr 2023 05:12:11 +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 3227A98650F for ; Wed, 12 Apr 2023 05:12:11 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: J2lE_jSLPNGslmi6j2IiQA-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681276328; 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=e/d3A4gx6awjnCS+UqmFyZ2zuplRG02Yk/eSwjUAJo8=; b=YZLtS2pW18LWqKtSq0rVivXh80p58V7x7/MaPqBnigzF2jU2VCNYiVOdH9rkXEoRIG Y5wrEW4BmCsCRz6ABpbpr2BHulg6i7Uxb6YhVPeud/VP82JnK7fosD5yMmDY9kbmYa5U redaN93xvRm5bc6lo/pz/cc3XwmrLCDS/WHT8NRqfllUEaox3P0xwhG/ltapZiQpwoyV GynKu+XUux1AYu9R9F35EadlS9XKXKCoxkdyK8CqKZUaVY3LSvfK0BelIC916BfE/86v MIZOddl4ujcNURFiXLfT+rZFE7LaEseyOUZ7M1aHBY/L6/ty5m43NWgrKAMOq9+MoqJY KqOg== X-Gm-Message-State: AAQBX9db3w8Mv8cgh/hCVYIGlQLcm0lhWJuJ1dPOo4glz9Ix11CvkgVO y1WpmfwctWh6bEOud3Gm0JU7dE8WrH0wNaIcYfZ6qtPznsk8t6QzuYpuEkB3m7uxDseYsJZR2XO fDSrGKThSgAXT3uUgctm1KlR+K5Ss2Z9hvw== X-Received: by 2002:a7b:cb45:0:b0:3ed:2eb5:c2dd with SMTP id v5-20020a7bcb45000000b003ed2eb5c2ddmr8492751wmj.39.1681276328105; Tue, 11 Apr 2023 22:12:08 -0700 (PDT) X-Google-Smtp-Source: AKy350bXTUapFTahVvq7aao4ki/GmR2Qf4y9Q9fdL7WZoCtVpOI5drrVDODleCRvW/uGp80Wj33cCg== X-Received: by 2002:a7b:cb45:0:b0:3ed:2eb5:c2dd with SMTP id v5-20020a7bcb45000000b003ed2eb5c2ddmr8492739wmj.39.1681276327825; Tue, 11 Apr 2023 22:12:07 -0700 (PDT) Date: Wed, 12 Apr 2023 01:12:04 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: "virtio-dev@lists.oasis-open.org" , "cohuck@redhat.com" , "virtio-comment@lists.oasis-open.org" , Shahaf Shuler Message-ID: <20230412010437-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230412004331-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-comment] Re: [PATCH 00/11] Introduce transitional mmr pci device On Wed, Apr 12, 2023 at 04:52:09AM +0000, Parav Pandit wrote: > > > From: Michael S. Tsirkin > > Sent: Wednesday, April 12, 2023 12:48 AM > > > Here is a counter proposal: > > > > #define VIRTIO_NET_F_LEGACY_HEADER 52 /* Use the legacy 10 byte > > header for all packets */ > > > > > > Yes, sorry to say, you need to emulate legacy pci in software. > > > > With notification hacks, and reset hacks, and legacy interrupt hacks, and > > writeable mac ... this thing best belongs in vdpa anyway. > > What? I don't follow. > Suddenly you attribute everything as hack with least explanation. > Again hacks is not a bad thing but it's an attempt at reusing things in unexpected ways. New issue I found today: - if guest disables MSI-X host can not disable MSI-X. need some other channel to notify device about this. Old issues we discussed before today: - reset needs some special handling because real hardware can not guarantee returning 0 on the 1st read - if guest writes into mac, reusing host mac (which is RO) will not work, need extra registers - something about notification makes you want to poke at modern notification register? which of course is its own can of worms with VIRTIO_F_NOTIFICATION_DATA changing the format completely. -- 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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