Re: [Xen-devel] [PATCH] VMX: wbinvd when vmentry under UC

["Liu, Jinsong" <jinsong.liu@xxxxxxxxx>]

Jan Beulich wrote:
>>>> "Liu, Jinsong" <jinsong.liu@xxxxxxxxx> 11/28/13 8:17 AM >>>
>> Liu, Jinsong wrote:
>>> Yes. reprogram_timer here just delay timer a little slot, say,
>>> 1~2ms. I think it's OK, i.e. at any point of wbinvd() operation at
>>> hypervisor, or any irq disabled area, timer interrupt in fact also
>>> has good chance to be delayed some time -- however at TIMER_SOFTIRQ,
>>> all expired thing would be executed, and re-calculated and set next
>>> time point via reprogram_timer -- that's OK.
>> 
>> Comments/thoughts about this option?
> 
> Apart from continuing to be very uncertain that this won't have any
> bad side effects, I'm also rather concerned that you deal with one
> special case interrupt here, ignoring other potentially high rate ones
> (like such coming from NICs).
> 
> Jan

Considering this, seems adding flag is the only work around way since high freq 
interrupt would result in dead-like-loop. My concern of adding flag is it's not 
easy to clean every possible path, especially future extension.

Or, do not support vt-d w/o snoop.

Thanks,
Jinsong
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel