Directly reserve an interrupt IDT entry for Hyper-V

[Roger Pau Monné]

On 20/08/14 17:31, John Baldwin wrote:
> On Wednesday, August 20, 2014 9:31:54 am Roger Pau Monné wrote:
>> Hello,
>>
>> I don't think using the same IDT vector is the right approach, I would
>> just pick a different IDT vector and use that for Hyper-V. Using the
>> same IDT vector (like your suggestion above) would prevent shipping a
>> kernel with with both Hyper-V and Xen support (like it's done now in
>> GENERIC).
>>
>> Roger.
> 
> Hmm, can't you make this a runtime check to only call setidt() if you detect 
> you are under the appropriate hypervisor?
> 
> Also, bhyve currently has a hackish way of requesting a free IDT slot.  
> Perhaps it would be best if I added little API to reserve an IDT slot assuming 
> that callers could accept a dynamic IDT vector rather than a static one.

That would work for Xen. The IDT vector doesn't need to be fixed since
it's registered with Xen when the system boots.

Roger.