(cc mailing lists) On Wed, 28 Jan 2009 12:26:16 -0200 Marcelo Tosatti <mtosatti@xxxxxxxxxx> wrote: > On Wed, Jan 28, 2009 at 11:20:16AM +0100, Alexander Graf wrote: > > > > On 28.01.2009, at 10:51, Andrew Morton wrote: > > > >> On Fri, 23 Jan 2009 12:34:24 -0800 Randy Dunlap > >> <randy.dunlap@xxxxxxxxxx> wrote: > >> > >>> Stephen Rothwell wrote: > >>>> Hi all, > >>>> > >>>> News: I will be on leave next week, so there will probably be no > >>>> linux-next release until Feb 2. > >>>> > >>>> Changes since 20090122: > >>> > >>> > >>> kvm changes cause this build error on i386: > >>> > >>> when kvm is built as module: > >>> ERROR: "__moddi3" [arch/x86/kvm/kvm.ko] undefined! > >>> > >>> or when kvm is built into the kernel image: > >>> lapic.c:(.text+0x19276): undefined reference to `__moddi3' > >>> > >>> > >>> I guess it's this line: > >>> ns = ktime_to_ns(remaining) % apic->timer.period; > >>> > >> > >> dammit, I just spent N minutes hunting down the same thing in > >> the Jan 26 linux-next :( > >> > > > > Yeah, Clemens Foss posted a real fix on kvm@vger already. Probably wasn't the best mailing list, as this bug affects all developers and testers.. But whatever - thanks. > commit efe4ff38b2bbc3944d0b2c9b6ec669b67cb7acbc > Author: Clemens Noss <cnoss@xxxxxx> > Date: Mon Jan 26 02:55:16 2009 +0100 > > KVM: x86: fix "__moddi3 undefined" build failure in lapic.c > > use mod_64 from arch/x86/kvm/i8254.c to fix > ERROR: "__moddi3" [arch/x86/kvm/kvm.ko] undefined! > > Signed-off-by: Clemens Noss <cnoss@xxxxxx> > Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index d8adc50..f0b67f2 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -35,6 +35,12 @@ > #include "kvm_cache_regs.h" > #include "irq.h" > > +#ifndef CONFIG_X86_64 > +#define mod_64(x, y) ((x) - (y) * div64_u64(x, y)) > +#else > +#define mod_64(x, y) ((x) % (y)) > +#endif > + > #define PRId64 "d" > #define PRIx64 "llx" > #define PRIu64 "u" > @@ -525,7 +531,7 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic) > if (ktime_to_ns(remaining) < 0) > remaining = ktime_set(0, 0); > > - ns = ktime_to_ns(remaining) % apic->timer.period; > + ns = mod_64(ktime_to_ns(remaining), apic->timer.period); > tmcct = div64_u64(ns, (APIC_BUS_CYCLE_NS * apic->timer.divide_count)); > > return tmcct; Rather than cooking up a private implementation I think it would be better to implement a kernel-wide mod64_u64() (?) facility and then to use that in KVM. There will presumably be other sites which will (or already do) need such a thing. However it'll probably be a bit hard, getting the signednesses of the args and the return value right. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
