Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264482AbTEPQPe (ORCPT ); Fri, 16 May 2003 12:15:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264485AbTEPQPd (ORCPT ); Fri, 16 May 2003 12:15:33 -0400 Received: from mailgw.cvut.cz ([147.32.3.235]:129 "EHLO mailgw.cvut.cz") by vger.kernel.org with ESMTP id S264482AbTEPQPc (ORCPT ); Fri, 16 May 2003 12:15:32 -0400 From: "Petr Vandrovec" Organization: CC CTU Prague To: Zwane Mwaikambo Date: Fri, 16 May 2003 18:28:07 +0200 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Re: [PATCH][2.5] VMWare doesn't like sysenter Cc: linux-kernel@vger.kernel.org, rddunlap@osdl.org X-mailer: Pegasus Mail v3.50 Message-ID: <1AF6C870AF5@vcnet.vc.cvut.cz> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2430 Lines: 58 On 15 May 03 at 11:15, Zwane Mwaikambo wrote: > On Thu, 15 May 2003, Randy.Dunlap wrote: > > > On Thu, 15 May 2003 04:02:31 -0400 (EDT) Zwane Mwaikambo wrote: > > > > | I get a monitor error in VMWare4 with a sysenter syscall enabled kernel, > > | this patch simply disables sysenter based syscalls but doesn't clear the > > | SEP bit in the capabilities. > > > > | +static int __init do_nosysenter(char *s) > > | +{ > > | + nosysenter = 1; > > | + return 1; > > | +} > > | +__setup("nosysenter", do_nosysenter); > > > > Needs entry in Documentation/kernel-parameters.txt also > > if/when accepted. > > Thanks for the heads up. > > Index: linux-2.5.69-mm5/Documentation/kernel-parameters.txt > =================================================================== > RCS file: /build/cvsroot/linux-2.5.69/Documentation/kernel-parameters.txt,v > retrieving revision 1.1.1.1 > diff -u -p -B -r1.1.1.1 kernel-parameters.txt > --- linux-2.5.69-mm5/Documentation/kernel-parameters.txt 6 May 2003 12:21:18 -0000 1.1.1.1 > +++ linux-2.5.69-mm5/Documentation/kernel-parameters.txt 15 May 2003 15:14:23 -0000 > @@ -1063,6 +1063,10 @@ running once the system is up. > > sym53c8xx= [HW,SCSI] > See Documentation/scsi/ncr53c8xx.txt. > + > + nosysenter [IA-32] > + Disable SYSENTER for syscalls, does not clear the SEP > + capabilities bit. RedHat's 9 backport of vsyscalls uses 'nosysinfo' name for option which does simillar task (it just stops kernel from reporting relevant AT_SYSINFO completely). BTW, what's reason for this backport? They just always put int 0x80 into this page, so even on real CPU kernel booted with nosysinfo is faster than one which uses this vsyscall entry point. VMware's panic should be fixed in next update, but I'm afraid that penalty from exectuing code in upper couple of MBs of address space will not disappear. Moving SYSINFO page from FFFFE000 to FF7FF000 (PKMAP_BASE - PAGE_SIZE == VMALLOC_END + PAGE_SIZE) would fix both problems. Petr Vandrovec vandrove@vc.cvut.cz - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/