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 X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 444D2C8300A for ; Thu, 30 Apr 2020 11:12:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D3F220757 for ; Thu, 30 Apr 2020 11:12:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="Mg6vKMa5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726929AbgD3LMR (ORCPT ); Thu, 30 Apr 2020 07:12:17 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:28589 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726309AbgD3LMQ (ORCPT ); Thu, 30 Apr 2020 07:12:16 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588245136; h=In-Reply-To: Content-Type: MIME-Version: References: Reply-To: Message-ID: Subject: Cc: To: From: Date: Sender; bh=XKOYbc1TPw2rm1iRNmfQra/wU/JM76LfaUCtYzQ89Ow=; b=Mg6vKMa5Bqf1+/+Qe+zu98T+UQ6YoVY+znWuwcf8VOx+mIXkqeibv4F/B4WWasBHJgTPyOhW aLcVV9dW1xfXlDOCMj1G70xukfLQGt4m3uIgB8zey3O5FJs93zBxO7M3DgGPQpOiaDPnB7JM mq+UUxqrAzvs+Rg8XUAVyu725cw= X-Mailgun-Sending-Ip: 104.130.122.27 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5eaab285.7f0f93947928-smtp-out-n01; Thu, 30 Apr 2020 11:12:05 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 87748C4478C; Thu, 30 Apr 2020 11:12:04 +0000 (UTC) Received: from quicinc.com (blr-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: svaddagi) by smtp.codeaurora.org (Postfix) with ESMTPSA id C4305C433F2; Thu, 30 Apr 2020 11:11:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C4305C433F2 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=vatsa@codeaurora.org Date: Thu, 30 Apr 2020 16:41:56 +0530 From: Srivatsa Vaddagiri To: Will Deacon Cc: konrad.wilk@oracle.com, mst@redhat.com, jasowang@redhat.com, jan.kiszka@siemens.com, stefano.stabellini@xilinx.com, iommu@lists.linux-foundation.org, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.org, tsoni@codeaurora.org, pratikp@codeaurora.org, christoffer.dall@arm.com, alex.bennee@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [RFC/PATCH 1/1] virtio: Introduce MMIO ops Message-ID: <20200430111156.GI5097@quicinc.com> Reply-To: Srivatsa Vaddagiri References: <1588240976-10213-1-git-send-email-vatsa@codeaurora.org> <1588240976-10213-2-git-send-email-vatsa@codeaurora.org> <20200430101431.GD19932@willie-the-truck> <20200430103446.GH5097@quicinc.com> <20200430104149.GG19932@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20200430104149.GG19932@willie-the-truck> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Will Deacon [2020-04-30 11:41:50]: > On Thu, Apr 30, 2020 at 04:04:46PM +0530, Srivatsa Vaddagiri wrote: > > If CONFIG_VIRTIO_MMIO_OPS is defined, then I expect this to be unconditionally > > set to 'magic_qcom_ops' that uses hypervisor-supported interface for IO (for > > example: message_queue_send() and message_queue_recevie() hypercalls). > > Hmm, but then how would such a kernel work as a guest under all the > spec-compliant hypervisors out there? Ok I see your point and yes for better binary compatibility, the ops have to be set based on runtime detection of hypervisor capabilities. > > Ok. I guess the other option is to standardize on a new virtio transport (like > > ivshmem2-virtio)? > > I haven't looked at that, but I suppose it depends on what your hypervisor > folks are willing to accomodate. I believe ivshmem2_virtio requires hypervisor to support PCI device emulation (for life-cycle management of VMs), which our hypervisor may not support. A simple shared memory and doorbell or message-queue based transport will work for us. -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation 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 X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04A5BC8300A for ; Thu, 30 Apr 2020 11:12:25 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BAB3020757 for ; Thu, 30 Apr 2020 11:12:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="tdni3ZMX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAB3020757 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 8C00F86BB9; Thu, 30 Apr 2020 11:12:24 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4b7e0Bew_t3Q; Thu, 30 Apr 2020 11:12:23 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 8E38E86BB3; Thu, 30 Apr 2020 11:12:22 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7A93DC0889; Thu, 30 Apr 2020 11:12:22 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id A5121C016F for ; Thu, 30 Apr 2020 11:12:21 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 8E8E886D2C for ; Thu, 30 Apr 2020 11:12:21 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KxdVZuKyVOun for ; Thu, 30 Apr 2020 11:12:21 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail26.static.mailgun.info (mail26.static.mailgun.info [104.130.122.26]) by fraxinus.osuosl.org (Postfix) with ESMTPS id A12CF86BB3 for ; Thu, 30 Apr 2020 11:12:16 +0000 (UTC) DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588245140; h=In-Reply-To: Content-Type: MIME-Version: References: Reply-To: Message-ID: Subject: Cc: To: From: Date: Sender; bh=XKOYbc1TPw2rm1iRNmfQra/wU/JM76LfaUCtYzQ89Ow=; b=tdni3ZMXL80YMNHUCzfb0mmeLxJ+PvijlK5pjwtuYh7sQ+a9ZH76HxP00Kxe6FxwiOoNJu9m //2qOe5Nl98oMIarh4XIcUEnLcitfP7PnBZ7WSL35xC8v8T10q3ErfB8GTjfIz0tgQuqvcfl AsKoxfdBz+iS/H+R3YGqW0bFUoI= X-Mailgun-Sending-Ip: 104.130.122.26 X-Mailgun-Sid: WyI3NDkwMCIsICJpb21tdUBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5eaab286.7f1b788efe68-smtp-out-n04; Thu, 30 Apr 2020 11:12:06 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 8A82CC44788; Thu, 30 Apr 2020 11:12:04 +0000 (UTC) Received: from quicinc.com (blr-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: svaddagi) by smtp.codeaurora.org (Postfix) with ESMTPSA id C4305C433F2; Thu, 30 Apr 2020 11:11:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C4305C433F2 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=vatsa@codeaurora.org Date: Thu, 30 Apr 2020 16:41:56 +0530 From: Srivatsa Vaddagiri To: Will Deacon Subject: Re: [RFC/PATCH 1/1] virtio: Introduce MMIO ops Message-ID: <20200430111156.GI5097@quicinc.com> References: <1588240976-10213-1-git-send-email-vatsa@codeaurora.org> <1588240976-10213-2-git-send-email-vatsa@codeaurora.org> <20200430101431.GD19932@willie-the-truck> <20200430103446.GH5097@quicinc.com> <20200430104149.GG19932@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200430104149.GG19932@willie-the-truck> User-Agent: Mutt/1.5.24 (2015-08-30) Cc: tsoni@codeaurora.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, jan.kiszka@siemens.com, jasowang@redhat.com, konrad.wilk@oracle.com, christoffer.dall@arm.com, virtualization@lists.linux-foundation.org, alex.bennee@linaro.org, iommu@lists.linux-foundation.org, stefano.stabellini@xilinx.com, pratikp@codeaurora.org, linux-kernel@vger.kernel.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Srivatsa Vaddagiri Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" * Will Deacon [2020-04-30 11:41:50]: > On Thu, Apr 30, 2020 at 04:04:46PM +0530, Srivatsa Vaddagiri wrote: > > If CONFIG_VIRTIO_MMIO_OPS is defined, then I expect this to be unconditionally > > set to 'magic_qcom_ops' that uses hypervisor-supported interface for IO (for > > example: message_queue_send() and message_queue_recevie() hypercalls). > > Hmm, but then how would such a kernel work as a guest under all the > spec-compliant hypervisors out there? Ok I see your point and yes for better binary compatibility, the ops have to be set based on runtime detection of hypervisor capabilities. > > Ok. I guess the other option is to standardize on a new virtio transport (like > > ivshmem2-virtio)? > > I haven't looked at that, but I suppose it depends on what your hypervisor > folks are willing to accomodate. I believe ivshmem2_virtio requires hypervisor to support PCI device emulation (for life-cycle management of VMs), which our hypervisor may not support. A simple shared memory and doorbell or message-queue based transport will work for us. -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu