Avi Kivity <[EMAIL PROTECTED]> wrote: > A "g" constraint may place a local variable in an %rsp-relative memory > operand. > but if your assembly changes %rsp, the operand points to the wrong location. > > An "r" constraint fixes that. > > Thanks to Ingo Molnar for neatly bisecting the problem. > > Signed-off-by: Avi Kivity <[EMAIL PROTECTED]> > > Index: linux-2.6/drivers/kvm/vmx.c > =================================================================== > --- linux-2.6.orig/drivers/kvm/vmx.c > +++ linux-2.6/drivers/kvm/vmx.c > @@ -1825,7 +1825,7 @@ again: > #endif > "setbe %0 \n\t" > "popf \n\t" > - : "=g" (fail) > + : "=r" (fail) > : "r"(vcpu->launched), "d"((unsigned long)HOST_RSP), > "c"(vcpu), > [rax]"i"(offsetof(struct kvm_vcpu, regs[VCPU_REGS_RAX])),
We need the following fix for 2.6.20. [KVM] vmx: Fix register constraint in launch code Both "=r" and "=g" breaks my build on i386: $ make CC [M] drivers/kvm/vmx.o {standard input}: Assembler messages: {standard input}:3318: Error: bad register name `%sil' make[1]: *** [drivers/kvm/vmx.o] Error 1 make: *** [_module_drivers/kvm] Error 2 The reason is that setbe requires an 8-bit register but "=r" does not constrain the target register to be one that has an 8-bit version on i386. According to http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10153 the correct constraint is "=q". Signed-off-by: Herbert Xu <[EMAIL PROTECTED]> Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index ce219e3..0aa2659 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -1824,7 +1824,7 @@ again: #endif "setbe %0 \n\t" "popf \n\t" - : "=g" (fail) + : "=q" (fail) : "r"(vcpu->launched), "d"((unsigned long)HOST_RSP), "c"(vcpu), [rax]"i"(offsetof(struct kvm_vcpu, regs[VCPU_REGS_RAX])), ------------------------------------------------------------------------- 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 _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel