Re: KVM: x86: update masterclock when kvmclock_offset is calculated

[Paolo Bonzini <pbonzini@redhat.com>]

Il 22/08/2013 19:05, Paolo Bonzini ha scritto:
> Il 20/08/2013 20:20, Marcelo Tosatti ha scritto:
>>
>> The offset to add to the hosts monotonic time, kvmclock_offset, is
>> calculated against the monotonic time at KVM_SET_CLOCK ioctl time.
>>
>> Request a master clock update at this time, to reduce a potentially
>> unbounded difference between the values of the masterclock and
>> the clock value used to calculate kvmclock_offset.
>>
>> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
>>
>> Index: linux-2.6-kvmclock-fixes/arch/x86/kvm/x86.c
>> ===================================================================
>> --- linux-2.6-kvmclock-fixes.orig/arch/x86/kvm/x86.c
>> +++ linux-2.6-kvmclock-fixes/arch/x86/kvm/x86.c
>> @@ -3806,6 +3806,7 @@ long kvm_arch_vm_ioctl(struct file *filp
>>  		delta = user_ns.clock - now_ns;
>>  		local_irq_enable();
>>  		kvm->arch.kvmclock_offset = delta;
>> +		kvm_gen_update_masterclock(kvm);
>>  		break;
>>  	}
>>  	case KVM_GET_CLOCK: {
> 
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Actually, what commit is this patch based on?  You are calling the 
function at line 3799, but it is only declared at line 5786, and this 
causes:

/root/kvm-kmod/x86/x86.c: In function ‘kvm_arch_vm_ioctl’:
/root/kvm-kmod/x86/x86.c:3799:3: error: implicit declaration of function ‘kvm_gen_update_masterclock’
/root/kvm-kmod/x86/x86.c: At top level:
/root/kvm-kmod/x86/x86.c:5786:13: warning: conflicting types for ‘kvm_gen_update_masterclock’
/root/kvm-kmod/x86/x86.c:5786:13: error: static declaration of ‘kvm_gen_update_masterclock’ follows non-static declaration
/root/kvm-kmod/x86/x86.c:3799:3: note: previous implicit declaration of ‘kvm_gen_update_masterclock’ was here

Paolo