On 20.10.2011, at 10:17, Bhushan Bharat-R65777 wrote: > > >> -----Original Message----- >> From: Alexander Graf [mailto:agraf@xxxxxxx] >> Sent: Thursday, October 20, 2011 10:45 PM >> To: Bhushan Bharat-R65777 >> Cc: kvm-ppc@xxxxxxxxxxxxxxx; bharatb.yadav@xxxxxxxxx; Bhushan Bharat- >> R65777 >> Subject: Re: [PATCH]KVM: Fix DEC truncation for greater than >> 0xffff_ffff/1000 >> >> >> On 18.10.2011, at 10:05, Bharat Bhushan wrote: >> >>> kvmppc_emulate_dec() uses dec_nsec of type unsigned long and does below >> calculation: >>> >>> dec_nsec = vcpu->arch.dec; >>> dec_nsec *= 1000; >>> This will truncate if DEC value "vcpu->arch.dec" is greater than >> 0xffff_ffff/1000. >>> For example : For tb_ticks_per_usec = 4a, we can not set decrementer >> more than ~58ms. >>> >>> Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx> >>> --- >>> arch/powerpc/kvm/emulate.c | 4 ++-- >>> 1 files changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c >>> index 8af3bad..37f41f9 100644 >>> --- a/arch/powerpc/kvm/emulate.c >>> +++ b/arch/powerpc/kvm/emulate.c >>> @@ -83,7 +83,7 @@ static bool kvmppc_dec_enabled(struct kvm_vcpu >>> *vcpu) >>> >>> void kvmppc_emulate_dec(struct kvm_vcpu *vcpu) { >>> - unsigned long dec_nsec; >>> + unsigned long long dec_nsec; >> >> u64 :) > > I think I have sent v2 of this patch. Please review that . > That also have long long :). Yup, didn't dig through my mail far enough yet when I posted this one :). Please change it to u64 nevertheless, makes it more readable. Alex -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
