From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH] make KVM conform to sucky rdmsr interface Date: Thu, 22 Mar 2007 14:30:11 -0700 Message-ID: <20070322143011.0cf83370.akpm@linux-foundation.org> References: <1174531917.2713.91.camel@localhost.localdomain> <46022E40.8080300@qumranet.com> <1174549770.2713.121.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Jeremy Fitzhardinge , lkml-MRDXTZLjjMs8G+1z+Pypc6QD96bmaF075NbjCUgZEJk@public.gmane.org, Mailing List , Andi Kleen , kvm-devel To: Rusty Russell Return-path: In-Reply-To: <1174549770.2713.121.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Thu, 22 Mar 2007 18:49:30 +1100 Rusty Russell wrote: > rdmsr_safe() takes pointers. rdmsr() modifies its arguments. What a > mess. > > Fix rdmsr_safe() with !CONFIG_PARAVIRT. > > Signed-off-by: Rusty Russell > > diff -r a7f78e8eacc8 include/asm-i386/msr.h > --- a/include/asm-i386/msr.h Thu Mar 22 12:38:35 2007 +1100 > +++ b/include/asm-i386/msr.h Thu Mar 22 18:40:35 2007 +1100 > @@ -96,12 +96,12 @@ static inline void wrmsrl (unsigned long > (native_write_msr(msr, ((unsigned long long)val2 << 32) | val1)) > > /* rdmsr with exception handling */ > -#define rdmsr_safe(msr,val1,val2) \ > +#define rdmsr_safe(msr,p1,p2) \ > ({ \ > int __err; \ > - unsigned long long __val = native_read_msr(msr, &__err); \ > - val1 = __val; \ > - val2 = __val >> 32; \ > + unsigned long long __val = native_read_msr(msr, &__err);\ > + (*p1) = __val; \ > + (*p2) = __val >> 32; \ > __err; \ > }) Linus's tree has /* rdmsr with exception handling */ #define rdmsr_safe(msr,a,b) ({ int ret__; \ asm volatile("2: rdmsr ; xorl %0,%0\n" \ "1:\n\t" \ ".section .fixup,\"ax\"\n\t" \ "3: movl %4,%0 ; jmp 1b\n\t" \ ".previous\n\t" \ ".section __ex_table,\"a\"\n" \ " .align 4\n\t" \ " .long 2b,3b\n\t" \ ".previous" \ : "=r" (ret__), "=a" (*(a)), "=d" (*(b)) \ : "c" (msr), "i" (-EFAULT));\ ret__; }) (secret decoder ring: resize your xterm to 100 cols to read the above. Sigh). Which tree are you patching?? ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV