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

[Christian Borntraeger]

>> 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.

>> --- 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