From owner-svn-src-head@freebsd.org Sat Aug 15 15:26:40 2015 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7382E9BABA4; Sat, 15 Aug 2015 15:26:40 +0000 (UTC) (envelope-from jason.harmening@gmail.com) Received: from mail-ob0-x22b.google.com (mail-ob0-x22b.google.com [IPv6:2607:f8b0:4003:c01::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 2CF1F1C99; Sat, 15 Aug 2015 15:26:40 +0000 (UTC) (envelope-from jason.harmening@gmail.com) Received: by obbop1 with SMTP id op1so82580036obb.2; Sat, 15 Aug 2015 08:26:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-type:content-transfer-encoding; bh=lG8lymsLK07EkuqIX04M+btnD0WCXX7h0/sHYMISkbY=; b=elv8MEgk1Ug4VOhSlp5hBXXymSRH2v1TvewpXhE7eydvHaQgg2GvZrUurUMoAO3fZf iphNJ8zls0QHYJGhhI8qoel6qVTOCMAUynAXyQUyDNRMFluflNcHwXdaGx2jSbW54Pn1 7Nnh41DKR7jFNRpoiwLwjQgdhnPa1RLKS011vROtMCFX6CI964IFukNlr9ptncD8jhcN yZ0dl0hGQjKXO1Y3AfzzxpmOlyMvc5mZ7ZQFJArWmdNfehFiOl7RI7H1ywlIr0sKIAto vACYOQ3LaXeaW2NP4F8oY1SW5loxWnA0ABbOr7uf0jOKK190t6Re3wNCDAe0GXul4aO+ xHDg== X-Received: by 10.182.43.228 with SMTP id z4mr23964207obl.48.1439652399450; Sat, 15 Aug 2015 08:26:39 -0700 (PDT) Received: from corona.austin.rr.com (cpe-72-177-6-10.austin.res.rr.com. [72.177.6.10]) by smtp.googlemail.com with ESMTPSA id ix8sm4753061obc.7.2015.08.15.08.26.38 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 15 Aug 2015 08:26:38 -0700 (PDT) Subject: Re: svn commit: r286787 - head/sys/x86/x86 To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , "Jason A. Harmening" , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <201508142008.t7EK8Hkt037329@repo.freebsd.org> <55CF390F.5010407@FreeBSD.org> From: Jason Harmening X-Enigmail-Draft-Status: N1110 Message-ID: <55CF5B13.1040501@gmail.com> Date: Sat, 15 Aug 2015 10:30:27 -0500 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <55CF390F.5010407@FreeBSD.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 15 Aug 2015 15:26:40 -0000 On 08/15/15 08:05, Roger Pau Monné wrote: > El 14/08/15 a les 22.08, Jason A. Harmening ha escrit: >> Author: jah >> Date: Fri Aug 14 20:08:16 2015 >> New Revision: 286787 >> URL: https://svnweb.freebsd.org/changeset/base/286787 >> >> Log: >> Use pmap_quick_enter_page() to handle bouncing of unmapped buffers in the x86 busdma_bounce implementation. Also treat user buffers as unmapped. >> This allows two things: >> 1. Sync'ing bounced maps in non-sleepable contexts. The physcopy* calls previously used could sleep on sf_buf operations in some cases. >> 2. Sync'ing user buffers outside the context of the owning process > > AFAICT this will break the Xen port. physcopy* uses uiomove_fromphys > that on the amd64 port is able to deal with pages outside of the DMAP. > OTOH pmap_quick_enter_page is not able to deal with pages outside of the > DMAP, and will simply panic. > > Roger. > Is it actually possible for those non-dom0 pages to be used for I/O that passes through busdma? If it is, then it would be easy to make pmap_quick_enter_page() handle them by adding a pcpu pageframe similar to what we do for i386.