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 4D6F8C77B7C for ; Sun, 21 May 2023 14:35:28 +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 7D08B2B079 for ; Sun, 21 May 2023 14:35:25 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 760469859EA for ; Sun, 21 May 2023 14:35:25 +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 6E9D59859E6; Sun, 21 May 2023 14:35:25 +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 53B9C9859E7 for ; Sun, 21 May 2023 14:35:03 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 3-eOVaQsMBaj3omjt1EudA-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684679698; x=1687271698; 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=rHqoc4F4yxRb8yZ7OYMj/uACmQ36I/uIlurzFZBRpos=; b=IjPbMXO7v+hX4oHGJAe7/oj62IIVuik3ofZtY4tSZ5ylt67OfyZ+TdT+fw8MRFIOwr zmz5oeVydoZx4Nd0JJsQG8/RsVfOj5pgFUuxNAtSGP45KW0ajUrjDKo4NDT1A+6Ts7rG 1JRpRwV1jCxgXyveFQ1sSasAYQQ0A2s3ipDifCNbJrjx4CVEYdfRWZ6a7yRGFeVz94ss lX+kSMv/S1S44C+/aLV643mv8lOwrA341gUi5sIsxm8QPI4DOy+/zveoIdzedetw/Phh lE3oAYRMU9RYMNafHq6r/coJILbLFX+0oREt2Rmno1oHzVq/SxUxZe8l03XFNRB/bgjN kpVg== X-Gm-Message-State: AC+VfDy18wiFtGzxFsPDELOCwmQx6LrkPdbI7pH6B5JAhM+fhJ9ODKjq ic7Z2h91/ZGAosXbbkAVhvh0AEFedU6opdF7vGsVAY3tx7tv1lJylTTGvotIfWBqfF+sc3e56II wZB0Re7Hvi6u2DJYKk9Ja9xmxw6UGtGCAkA== X-Received: by 2002:adf:f591:0:b0:307:8ea4:f8f5 with SMTP id f17-20020adff591000000b003078ea4f8f5mr7941302wro.27.1684679698006; Sun, 21 May 2023 07:34:58 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ63IY+4tlu+WfT8NNqgQR3DUYj2a0heaxtl4gv+zQwiwiuKe4NfzaYmpqzVZm9nZZDhEdyXuw== X-Received: by 2002:adf:f591:0:b0:307:8ea4:f8f5 with SMTP id f17-20020adff591000000b003078ea4f8f5mr7941291wro.27.1684679697674; Sun, 21 May 2023 07:34:57 -0700 (PDT) Date: Sun, 21 May 2023 10:34:54 -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: <20230521103341-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230330225834.506969-9-parav@nvidia.com> <20230519020737-mutt-send-email-mst@kernel.org> <20230521015236-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 08/11] transport-pci: Introduce virtio extended capability On Sun, May 21, 2023 at 01:24:55PM +0000, Parav Pandit wrote: > > From: Michael S. Tsirkin > > Sent: Sunday, May 21, 2023 1:58 AM > > > Yes but neither can it support new devices because it does not look for the new > > device id. So it's fine - I was talking about new devices using extended > > capability. > > > > We shouldn't just laser-focus on existing software and devices, there's probably > > more to come. > > > Sure, new devices can use new capability. > I will roll this as separate patch and github issue. > As we discussed, legacy register access over AQ does not need this capability anyway. > > So not related to v2 discussion. > I am in middle of splitting this as separate patch unrelated to the v2 for legacy access. > > > > > > But that is the case with any existing software, not just seabios. > > > > > > New capability is in addition to the existing one. > > > And code already exists to refer to the old one, so I am not seeing any gain to > > create them now. > > > Any new capability that one creates in the future can be in the extended area. > > > > Question is about MCFG in general. Is adding capability to access MCFG to > > seabios for pci accesses practical? hard? > > > What is MCFG? This is the name of the ACPI table describing memory mapped pci config accesses. > > > You mentioned a perf angle that it takes half the time, but I don't > > > see how as the only change between legacy and ext is: offset. > > > > For a variety of reasons Linux does not use memory mapped accesses for legacy > > config space, it uses cf8/cfc for that. > And does it use memory mapped accesses for non-legacy config space? No other way to access that, right? -- 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 888D4C7EE23 for ; Sun, 21 May 2023 14:35:24 +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 D3C4C179147 for ; Sun, 21 May 2023 14:35:23 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id BDF26986197 for ; Sun, 21 May 2023 14:35:23 +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 ACB0A9859E5; Sun, 21 May 2023 14:35:23 +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 BB8DA9859E6 for ; Sun, 21 May 2023 14:35:01 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: eaemW_9ONYy3_KDVns-Qzg-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684679698; x=1687271698; 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=rHqoc4F4yxRb8yZ7OYMj/uACmQ36I/uIlurzFZBRpos=; b=DFebShAkeVvi5fEWUZ9nEAJ2DHtRRgpOJn7pF18cQpaYkzVUIyKH1B/Ig+qk87WLQY KrMozHz47CiUtkpw73f5pMP/NNF5ohiqxYl8JZJ6uD5AnEzT1AzHXRcEaVzSCc2k+6lh 45ofoQHflhLQFRwE7OXzAttl+FuPH6VgTcuY3JaE0UM9sHSiducwubOhiTxVlsOxat05 SdXY0ML2TBazpenDhRULnijYLeMOQcb66hGlViJA6orYHCrGxmMCkq2Pu4AIPi79SwYj mHm7O+SdTKAjcsJY35IE7ITPJCcEnRH38V8XcipIERPJ1jwxEKNBv3jmJvBDPz6kEFRE L8Bg== X-Gm-Message-State: AC+VfDw+fwN4c4qCIM5SbwvgmBVKNNDybhz0hgWzj5+XReSCbKPuE3Ct 1b32wjIOAvDy7vgM64JWAhkc21/j2dlFVBWYa6YS+C4EDIEL4U0qzg9SQj0c9yU4xB8Au8d7jbB +5NZuO1p8MVqN4dI/PPbOfvafVu8HCiItVwZ7 X-Received: by 2002:adf:f591:0:b0:307:8ea4:f8f5 with SMTP id f17-20020adff591000000b003078ea4f8f5mr7941301wro.27.1684679698006; Sun, 21 May 2023 07:34:58 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ63IY+4tlu+WfT8NNqgQR3DUYj2a0heaxtl4gv+zQwiwiuKe4NfzaYmpqzVZm9nZZDhEdyXuw== X-Received: by 2002:adf:f591:0:b0:307:8ea4:f8f5 with SMTP id f17-20020adff591000000b003078ea4f8f5mr7941291wro.27.1684679697674; Sun, 21 May 2023 07:34:57 -0700 (PDT) Date: Sun, 21 May 2023 10:34:54 -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: <20230521103341-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230330225834.506969-9-parav@nvidia.com> <20230519020737-mutt-send-email-mst@kernel.org> <20230521015236-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 08/11] transport-pci: Introduce virtio extended capability On Sun, May 21, 2023 at 01:24:55PM +0000, Parav Pandit wrote: > > From: Michael S. Tsirkin > > Sent: Sunday, May 21, 2023 1:58 AM > > > Yes but neither can it support new devices because it does not look for the new > > device id. So it's fine - I was talking about new devices using extended > > capability. > > > > We shouldn't just laser-focus on existing software and devices, there's probably > > more to come. > > > Sure, new devices can use new capability. > I will roll this as separate patch and github issue. > As we discussed, legacy register access over AQ does not need this capability anyway. > > So not related to v2 discussion. > I am in middle of splitting this as separate patch unrelated to the v2 for legacy access. > > > > > > But that is the case with any existing software, not just seabios. > > > > > > New capability is in addition to the existing one. > > > And code already exists to refer to the old one, so I am not seeing any gain to > > create them now. > > > Any new capability that one creates in the future can be in the extended area. > > > > Question is about MCFG in general. Is adding capability to access MCFG to > > seabios for pci accesses practical? hard? > > > What is MCFG? This is the name of the ACPI table describing memory mapped pci config accesses. > > > You mentioned a perf angle that it takes half the time, but I don't > > > see how as the only change between legacy and ext is: offset. > > > > For a variety of reasons Linux does not use memory mapped accesses for legacy > > config space, it uses cf8/cfc for that. > And does it use memory mapped accesses for non-legacy config space? No other way to access that, right? -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org