Re: [Xen-ia64-devel] [PATCH] emulate PAL_HALT_LIGHT on domU

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

Hi Sakai.

xenLinux/x86 paravirtualizes idle loop to get timer interrupt
while cpu halting.
More exactly safe_halt() is paravirtualized using
HYPERVISOR_set_timer_op().
Xen/IA64 doesn't support HYPERVISOR_set_timer_op(), but it
would be quite easy to add its support.

I'm not sure about which is better, your approach or paravirtualizing
idle loop.
Could you explain the reason why you added vcpu->arch.hlt_timer
instead of supporting set_timer_op hypercall with vcpu->timer?

Thanks.

On Wed, Jul 05, 2006 at 12:46:35PM +0900, Atsushi SAKAI wrote:
> Hi, All
> 
> This patch emulates Guest PAL_HALT_LIGHT on domU by using do_block and timer.
> It also adds the function of the timer event sending to domU at the vcpu woke 
> up.
> 
> Signed-off-by: Atsushi SAKAI <sakaia@xxxxxxxxxxxxxx>
> 
> 
> About the timer event sending to domU
> 
> The function "xen_timer_interrupt" on ParaVM/IA64 only sends 
> the timer signal to current vcpu.
> When the idle domain is running, no domUx receives timer signal.
> If some domain cannot receive the timer signal during 10 secs,
> a message "BUG: soft lockup detected appeared" comes from domUx.
> To avoid this, I add a timer check routine at the vcpu woke up.
> 
> I tested a few days.
> 
> Thanks,
> Atsushi SAKAI
> 
> 
> 


> _______________________________________________
> Xen-ia64-devel mailing list
> Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-ia64-devel

-- 
yamahata

_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel