Re: [PATCH] kvm-vmx: add module parameter to avoid trapping HLT instructions (v2)

[Avi Kivity <avi@redhat.com>]

On 12/04/2010 03:30 PM, Anthony Liguori wrote:
> On 12/04/2010 02:13 AM, Avi Kivity wrote:
>> On 12/04/2010 12:45 AM, Anthony Liguori wrote:
>>>> hlt exiting doesn't leave vcpu in the halted state (since hlt has 
>>>> not been executed).  So currently we never see a vcpu in halted state.
>>>
>>>
>>> Right, you mean the guest activity state being halt.
>>>
>>> My understanding is that it just needs to be cleared on exception 
>>> injection.  Would could clear it at every vmentry but that would 
>>> introduce a vmcs_read() to the fast path which is undesirable.
>>
>> Also need to skip the hlt instruction (by calling the emulator for 
>> example).
>
> I wasn't sure about this.  Don't you want EIP to point to the 
> beginning of the instruction such that the exception will cause the 
> instruction to restart?

An interrupt causes the HLT to complete execution.   APF completion 
counts as an interrupt in this case.

-- 
error compiling committee.c: too many arguments to function