From owner-cvs-src@FreeBSD.ORG Fri Aug 8 19:25:21 2008 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A821A1065670; Fri, 8 Aug 2008 19:25:21 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (bigknife-pt.tunnel.tserv9.chi1.ipv6.he.net [IPv6:2001:470:1f10:75::2]) by mx1.freebsd.org (Postfix) with ESMTP id 474C08FC08; Fri, 8 Aug 2008 19:25:21 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from localhost.corp.yahoo.com (john@localhost [IPv6:::1]) (authenticated bits=0) by server.baldwin.cx (8.14.2/8.14.2) with ESMTP id m78JPDCD031349; Fri, 8 Aug 2008 15:25:14 -0400 (EDT) (envelope-from jhb@freebsd.org) From: John Baldwin To: Kostik Belousov Date: Fri, 8 Aug 2008 14:59:54 -0400 User-Agent: KMail/1.9.7 References: <200808081631.m78GVG9i088754@repoman.freebsd.org> <200808081427.42536.jhb@freebsd.org> <20080808185133.GG97161@deviant.kiev.zoral.com.ua> In-Reply-To: <20080808185133.GG97161@deviant.kiev.zoral.com.ua> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200808081459.54735.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [IPv6:::1]); Fri, 08 Aug 2008 15:25:14 -0400 (EDT) X-Virus-Scanned: ClamAV 0.93.1/7981/Fri Aug 8 11:29:53 2008 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.5 required=4.2 tests=AWL,BAYES_00,NO_RELAYS autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: Stanislav Sedov , cvs-src@freebsd.org, src-committers@freebsd.org, cvs-all@freebsd.org Subject: Re: cvs commit: src/share/man/man4 Makefile cpuctl.4 src/sys/amd64/amd64 support.S src/sys/amd64/conf NOTES src/sys/amd64/include cpufunc.h specialreg.h src/sys/conf files.amd64 files.i386 src/sys/dev/cpuctl cpuctl.c ... X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Aug 2008 19:25:21 -0000 On Friday 08 August 2008 02:51:33 pm Kostik Belousov wrote: > On Fri, Aug 08, 2008 at 02:27:42PM -0400, John Baldwin wrote: > > On Friday 08 August 2008 02:10:52 pm Kostik Belousov wrote: > > > On Fri, Aug 08, 2008 at 12:51:17PM -0400, John Baldwin wrote: > > > > On Friday 08 August 2008 12:26:53 pm Stanislav Sedov wrote: > > > > > stas 2008-08-08 16:26:53 UTC > > > > > > > > > > FreeBSD src repository > > > > > > > > > > Modified files: > > > > > share/man/man4 Makefile > > > > > sys/amd64/amd64 support.S > > > > > sys/amd64/conf NOTES > > > > > sys/amd64/include cpufunc.h specialreg.h > > > > > sys/conf files.amd64 files.i386 > > > > > sys/i386/conf NOTES > > > > > sys/i386/i386 support.s > > > > > sys/i386/include cpufunc.h specialreg.h > > > > > sys/modules Makefile > > > > > sys/sys priv.h > > > > > usr.sbin Makefile > > > > > Added files: > > > > > share/man/man4 cpuctl.4 > > > > > sys/dev/cpuctl cpuctl.c > > > > > sys/modules/cpuctl Makefile > > > > > sys/sys cpuctl.h > > > > > usr.sbin/cpucontrol Makefile amd.c amd.h cpucontrol.8 > > > > > cpucontrol.c cpucontrol.h intel.c intel.h > > > > > Log: > > > > > SVN rev 181430 on 2008-08-08 16:26:53Z by stas > > > > > > > > > > - Add cpuctl(4) pseudo-device driver to provide access to some > > low-level > > > > > features of CPUs like reading/writing machine-specific registers, > > > > > retrieving cpuid data, and updating microcode. > > > > > - Add cpucontrol(8) utility, that provides userland access to > > > > > the features of cpuctl(4). > > > > > - Add subsequent manpages. > > > > > > > > > > The cpuctl(4) device operates as follows. The pseudo-device node > > cpuctlX > > > > > is created for each cpu present in the systems. The pseudo-device > > minor > > > > > number corresponds to the cpu number in the system. The cpuctl(4) > > pseudo- > > > > > device allows a number of ioctl to be preformed, namely > > RDMSR/WRMSR/CPUID > > > > > and UPDATE. The first pair alows the caller to read/write > > machine-specific > > > > > registers from the correspondent CPU. cpuid data could be retrieved > > using > > > > > the CPUID call, and microcode updates are applied via UPDATE. > > > > > > > > > > The permissions are inforced based on the pseudo-device file > > permissions. > > > > > RDMSR/CPUID will be allowed when the caller has read access to the > > device > > > > > node, while WRMSR/UPDATE will be granted only when the node is opened > > > > > for writing. There're also a number of priv(9) checks. > > > > > > > > > > The cpucontrol(8) utility is intened to provide userland access to > > > > > the cpuctl(4) device features. The utility also allows one to apply > > > > > cpu microcode updates. > > > > > > > > > > Currently only Intel and AMD cpus are supported and were tested. > > > > > > > > Note that cpuid isn't a privileged instruction, so I'm not sure it's > > really > > > > worth having an ioctl for that particular case. > > > > > > It was discussed when patch was reviewed on current@. The ioctl allows > > > to get cpuid information for specific processor, as opposed to some > > > random core curthread happens to run ATM. > > > > You can achieve that now with cpuset. :) (See my ping-pong test program > > recently which used cpuid to fetch the APIC ID to test for ping-ponging in > > the scheduler.) > > If this is a backout request (for cpuid functionality) then we will do it. > > But I considered it much easier and cleaner to do > fd = open("/dev/cpuctlN", O_RDWR); > ioctl(fd, CPUCTL_CPUID, &x); > if (x.y) > ioctl(fd, CPUCTL_WRMSR, ...); > close(fd); > then > fd = open("/dev/cpuctlN", O_RDWR); > cpuset(...); /* bind to cpu */ > __asm__("cpuid" : =0 (x)); > if (x.y) > ioctl(fd, CPUCTL_WRMSR, ...); > cpuset(...); /* restore prev mask */ > close(fd); You can leave it. It is useful to specify the CPU I suppose. -- John Baldwin