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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 B79ADC282C7 for ; Tue, 29 Jan 2019 04:14:20 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 5CC002147A for ; Tue, 29 Jan 2019 04:14:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ozlabs.org header.i=@ozlabs.org header.b="TwuWaQh9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CC002147A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ozlabs.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 43pY6L1lh8zDqNg for ; Tue, 29 Jan 2019 15:14:18 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 43pY4Y5SpszDq7g for ; Tue, 29 Jan 2019 15:12:45 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.b="TwuWaQh9"; dkim-atps=neutral Received: by ozlabs.org (Postfix, from userid 1003) id 43pY4Y3Xjxz9sDL; Tue, 29 Jan 2019 15:12:45 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1548735165; bh=bD32aIVYjRJQf5VZA8UIAFhQqDDyZSz+PPu5olsSJNo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TwuWaQh97bUvcGFn9N5CfmKr1LY07LjcACRliXrKukdVOYQLR2b0xBbSlbdHVVSfX ReTGRV4BS+djMDLEBejG47+6QxUtL2jrtKdEPX7YHBSc3wa1L5uMQ26t2uGhUQMIPG ElvqZTgxaiGUtoQfhETihw35criq71eroMZi1CMxQj1ZjfP1WkhKbp3xa5my1peMXV aRCDVNRuZIdsdUY7fb3FwtiKD+pP+UmUSiuckncBLdSAwupQna09eYEZKYvxzBnJPd B6I1Z5mnLyttqWegbYDsVK6Kwqa7mZ2btrB7AqxXbrTxWUUcSoqyzkqEo4P8PFssYi s5tgLttYbU0cw== Date: Tue, 29 Jan 2019 15:12:41 +1100 From: Paul Mackerras To: =?iso-8859-1?Q?C=E9dric?= Le Goater Subject: Re: [PATCH 18/19] KVM: PPC: Book3S HV: add passthrough support Message-ID: <20190129041241.GA17660@blackberry> References: <20190107184331.8429-1-clg@kaod.org> <20190107191006.10648-1-clg@kaod.org> <20190107191006.10648-2-clg@kaod.org> <20190122052657.GG15124@blackberry> <20190123103009.GB29826@blackberry> <75762dbe-0f08-5b06-e376-744ff87ff4cb@kaod.org> <20190128061353.GD3237@blackberry> <38b0244d-beb6-3aee-c638-279ca570633c@kaod.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <38b0244d-beb6-3aee-c638-279ca570633c@kaod.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, David Gibson Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Jan 28, 2019 at 07:26:00PM +0100, Cédric Le Goater wrote: > > Is clearing the PTEs and repopulating the VMA unsafe ? Actually, now that I come to think of it, there could be any number of VMAs (well, up to almost 64k of them), since once you have a file descriptor you can call mmap on it multiple times. The more I think about it, the more I think that getting userspace to manage the mappings with mmap() and munmap() is the right idea if it can be made to work. Paul.