Re: [Qemu-devel] [PATCH] kvm: notify host when guest panicked

[Wen Congyang]

At 06/12/2012 03:49 PM, Christian Borntraeger Wrote:
>>> We have three solutions to implement this feature:
>>> 1. use vmcall
>>> 2. use I/O port
>>> 3. use virtio-serial.
>>
>>> We have decided to avoid touching hypervisor. The reason why I choose
>>> choose the I/O port is:
>>> 1. it is easier to implememt
>>> 2. it does not depend any virtual device
>>> 3. it can work when startint the kernel
> 
> Havent looked deeply into that, butz wouldnt kvm_hypercall0 also fulfill all 
> of these
> points? You just have to define the number for each architecture and then it 
> should be 
> possible to write a simple panic driver that works on all architectures.

kvm_hypercall0? Avi said that we should avoid touching hypercall.

Thanks
Wen Congyang

> 
>>> --- a/include/linux/kvm_para.h
>>> +++ b/include/linux/kvm_para.h
>>> @@ -20,6 +20,14 @@
>>>  #define KVM_HC_FEATURES                    3
>>>  #define KVM_HC_PPC_MAP_MAGIC_PAGE  4
>>>  
>>> +#define KVM_PV_PORT        (0x505UL)
>>> +
> 
> ignoring the above, shouldnt a port number go into an architecture specific 
> file?
> 
> 
> Christian
> 
>