lkml.org 
[lkml]   [2006]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [kvm-devel] [PATCH] KVM: Avoid using vmx instruction directly
Arnd Bergmann wrote:
> On Thursday 09 November 2006 15:52, Avi Kivity wrote:
>
>> Wouldn't that make inline assembly useless? Suppose the contents is
>> itself a pointer. What about the pointed-to contents?
>>
>> e.g.
>>
>> int x = 3;
>> int *y = &x;
>> int z;
>>
>> asm ("mov %1, %%rax; movl (%%rax), %0" : "=r"(z) : "g"(y) : "rax");
>> assert(z == 3);
>>
>
> Same here, you need to tell gcc what is really accessed, like
>
> asm ("mov %1, %%rax; movl (%%rax), %0" : "=r"(z) : "g"(y), "m"(*y) : "rax");
>
> I know that the s390 kernel developers have hit that problem
> frequently with inline assemblies. It may be that it's harder
> to hit on x86, because there are fewer registers available and
> data therefore tends to spill to the stack.
>

I'll update my tree to reflect this. Thanks.

--
error compiling committee.c: too many arguments to function

-
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/

\
 
 \ /
  Last update: 2006-11-09 17:55    [W:0.210 / U:0.504 seconds]
©2003-2014 Jasper Spaans. Advertise on this site