Re: [kvm-devel] [PATCH] KVM: Avoid using vmx instruction directly

[Avi Kivity <avi@qumranet.com>]

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

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