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 EE397C77B73 for ; Wed, 12 Apr 2023 05:17:10 +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 4F3A942B68 for ; Wed, 12 Apr 2023 05:17:10 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 47B7E986520 for ; Wed, 12 Apr 2023 05:17:10 +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 3E55A98650E; Wed, 12 Apr 2023 05:17:10 +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 2EAC098650F for ; Wed, 12 Apr 2023 05:17:10 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: D5PfGfPONNq02U15lkbGig-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681276627; 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=zRWvovlSBjnAK75vdU/qypXHIkReoHAfqmY3XHghr0E=; b=AaL7LlBKQKC3EO0onQVnzam+S+VwgoEUx++Vc/m0IXNT60MSjLgB2FPef6cOKKBUrh laz/A2XNgwrBN9vpRl7mjVOMxhZTn1zDOCimIONq9ka2MoxRvYAIhNXr27UpV9Bx/KYW 3Q7nwgBGE5/Fa8+L5inBkC6pPZwErv2s40sCbjDAopahF7H2jkf2Oxf9bawNzcE3gf+N sqVH6PawiVU4M5n2sjYlLGPf8eh13pHis60VLSo914t+cpgLPWtykSfA1S8flKyypCiY JDxuzjblUGx3mrmunyNm6+GgxC9IZUvXJoqOgoafMMvWYkr72Z+8bwvrADqqrQFfBRCp GT1Q== X-Gm-Message-State: AAQBX9ehZjl5EWLoo+1A0eNvsQJnZZQTSJdnHowTFJyG/F9ri4Iz1lKj 5WdypXs2d9GVvXC/YXVHa4Dp9ksE9nT28gWdvsyARIFtOr55DS7ILgu/TARSEFoGhyGA0u3DLvG lqS8voPiGPgqqJxRl90qDTLeg6zzlhDn4zQ== X-Received: by 2002:a05:600c:2247:b0:3eb:2b88:a69a with SMTP id a7-20020a05600c224700b003eb2b88a69amr8296767wmm.14.1681276627241; Tue, 11 Apr 2023 22:17:07 -0700 (PDT) X-Google-Smtp-Source: AKy350bImKrhWp/WA9TY0H5mJOS1hKB072X249wrw1onVdhUY9TCWogJuSVklexVvC+G9Pmp/V4M6A== X-Received: by 2002:a05:600c:2247:b0:3eb:2b88:a69a with SMTP id a7-20020a05600c224700b003eb2b88a69amr8296754wmm.14.1681276626912; Tue, 11 Apr 2023 22:17:06 -0700 (PDT) Date: Wed, 12 Apr 2023 01:17:03 -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 , Satananda Burla Message-ID: <20230412011222-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230330225834.506969-11-parav@nvidia.com> <20230412003006-mutt-send-email-mst@kernel.org> <20230412004152-mutt-send-email-mst@kernel.org> <20230412010224-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] Re: [PATCH 10/11] transport-pci: Use driver notification PCI capability On Wed, Apr 12, 2023 at 05:06:09AM +0000, Parav Pandit wrote: > > > > From: virtio-comment@lists.oasis-open.org > open.org> On Behalf Of Michael S. Tsirkin > > > > On that occurrence, hypervisor driver forwards the q notification using the q > > notification region which is defined by struct virtio_pci_notify_cap. > > > > What is wrong with forwarding it on the legacy window? > Legacy window is configuration registers. > One has sandwitched q notification register in middle of all the config registers. > Such registers do not start the VQ data path engines. > 1.x spec has done the right thing to have dedicated notification region which something an actual pci hw can implement. okay so.. in fact it turns out existing hardware is not really happy to emulate legacy. it does not really fit that well. so maybe we should stop propagating the legacy interface to modern hardware then. Add the legacy net header size feature and be done with it. -- MST This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. 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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 3F0C5C77B75 for ; Wed, 12 Apr 2023 05:17:12 +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 8C8EB44378 for ; Wed, 12 Apr 2023 05:17:11 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 86C669865B5 for ; Wed, 12 Apr 2023 05:17:11 +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 79B7B986511; Wed, 12 Apr 2023 05:17:11 +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 6963998650F for ; Wed, 12 Apr 2023 05:17:11 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: xxtDPiDfNxKXUE7wUZ6p_w-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681276627; 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=zRWvovlSBjnAK75vdU/qypXHIkReoHAfqmY3XHghr0E=; b=Mt7+MaHTAvIrQujiU54H+vkj3RexZ3XGHgTpJJg8AnPtlldBDmDvgTTo0b2F2uSYda vDI3OxwFpyN1ZL+sPtCSTLXml+adVP1+1+twC2EYV7dvpxXjpXg7psNacNQg5meyGKEU ZskaX+pOXeS03odRVqqU3IEyF1Zdaa9zownYoKBoFhBwF/N3l3EBY2GeeeeAwlhdZbsj GRH6x/AecNLRA1W/utZ6/0V1DpaMKSzsBkcPjDCsLc/TcEgU3Xdj7pgk2HPbmO3W7izO /gXRZwVaVjVBvO39vXe5610CUgBCfRtMLGSE9/nCq8H4wlM9syhzQwSRxyEFejBljjjb TDog== X-Gm-Message-State: AAQBX9d+c6Or4WgZyepKRGm5U56cin6cxfQZ0neejE04baonNtIxGT3p QZFUkZsAknN6tLCBQq4AtPqB614UvnosRb0j98xyDjdwUikbMy5cgIZMDyXR0USsU/WNlztFagM CXOUDdBVs6maS/N6kNzvu/xHkeIdoOnC1B6KD X-Received: by 2002:a05:600c:2247:b0:3eb:2b88:a69a with SMTP id a7-20020a05600c224700b003eb2b88a69amr8296770wmm.14.1681276627242; Tue, 11 Apr 2023 22:17:07 -0700 (PDT) X-Google-Smtp-Source: AKy350bImKrhWp/WA9TY0H5mJOS1hKB072X249wrw1onVdhUY9TCWogJuSVklexVvC+G9Pmp/V4M6A== X-Received: by 2002:a05:600c:2247:b0:3eb:2b88:a69a with SMTP id a7-20020a05600c224700b003eb2b88a69amr8296754wmm.14.1681276626912; Tue, 11 Apr 2023 22:17:06 -0700 (PDT) Date: Wed, 12 Apr 2023 01:17:03 -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 , Satananda Burla Message-ID: <20230412011222-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230330225834.506969-11-parav@nvidia.com> <20230412003006-mutt-send-email-mst@kernel.org> <20230412004152-mutt-send-email-mst@kernel.org> <20230412010224-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] Re: [PATCH 10/11] transport-pci: Use driver notification PCI capability On Wed, Apr 12, 2023 at 05:06:09AM +0000, Parav Pandit wrote: > > > > From: virtio-comment@lists.oasis-open.org > open.org> On Behalf Of Michael S. Tsirkin > > > > On that occurrence, hypervisor driver forwards the q notification using the q > > notification region which is defined by struct virtio_pci_notify_cap. > > > > What is wrong with forwarding it on the legacy window? > Legacy window is configuration registers. > One has sandwitched q notification register in middle of all the config registers. > Such registers do not start the VQ data path engines. > 1.x spec has done the right thing to have dedicated notification region which something an actual pci hw can implement. okay so.. in fact it turns out existing hardware is not really happy to emulate legacy. it does not really fit that well. so maybe we should stop propagating the legacy interface to modern hardware then. Add the legacy net header size feature and be done with it. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org