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 2B4E9C8300C for ; Thu, 30 Apr 2020 10:30:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 072C92137B for ; Thu, 30 Apr 2020 10:30:12 +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="Yl1Lo1IR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726950AbgD3KaL (ORCPT ); Thu, 30 Apr 2020 06:30:11 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:63566 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726907AbgD3KaJ (ORCPT ); Thu, 30 Apr 2020 06:30:09 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588242608; h=In-Reply-To: Content-Type: MIME-Version: References: Reply-To: Message-ID: Subject: Cc: To: From: Date: Sender; bh=k1Dl4yzC1omqlWq2Asz34n/944KUyAHUVkIZtMS/CJo=; b=Yl1Lo1IRrzZGr5pwN5aeQAURkb6bPcfXx/bA0bE7Ab1d1FBeOHuhov7mEzugBwC+Xclknt1a p4qgRzKY+I7Wh++jsrxhIla0SorpLFh32srAyQzy7OCOAMn0KKvPA1fGP35MQ1SOXeYMd6XH wqoQ4hG7IcOy29FmXu/vuHXja6w= 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 5eaaa89d.7f97a7408180-smtp-out-n03; Thu, 30 Apr 2020 10:29:49 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id B4689C44793; Thu, 30 Apr 2020 10:29:48 +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 EF410C433CB; Thu, 30 Apr 2020 10:29:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org EF410C433CB 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 15:59:39 +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 0/1] virtio_mmio: hypervisor specific interfaces for MMIO Message-ID: <20200430102939.GG5097@quicinc.com> Reply-To: Srivatsa Vaddagiri References: <1588240976-10213-1-git-send-email-vatsa@codeaurora.org> <20200430100821.GC19932@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20200430100821.GC19932@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 11:08:22]: > > This patch is meant to seek comments. If its considered to be in right > > direction, will work on making it more complete and send the next version! > > What's stopping you from implementing the trapping support in the > hypervisor? Unlike the other patches you sent out, where the guest memory > is not accessible to the host, there doesn't seem to be any advantage to > not having trapping support, or am I missing something here? Hi Will, I have had this discussion with hypervisor folks. They seem to be concerned about complexity of having a VM's fault be handled in another untrusted VM. They are not keen to add MMIO support. -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation