Re: [PATCH 3/5] xen/vm_event: Support for guest-requested events

[Razvan Cojocaru <rcojocaru@bitdefender.com>]

On 05/08/2015 07:50 PM, Andrew Cooper wrote:
> On 06/05/15 18:12, Razvan Cojocaru wrote:
>> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
>> index 86f9885..8ad03c6 100644
>> --- a/xen/arch/x86/hvm/hvm.c
>> +++ b/xen/arch/x86/hvm/hvm.c
>> @@ -6267,6 +6267,10 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
>>          break;
>>      }
>>  
>> +    case HVMOP_request_vm_event:
>> +        hvm_event_requested();
>> +        break;
>> +
> 
> This is much better than the previous version, but there is nothing
> HVM-specific about having an arbitrary signal to the vm_event subsystem.
> 
> It might be better to chose a different hypercall to hang a subop off. 
> On the other hand, we already have things like HVMOP_xentrace, and there
> is nothing actually preventing PV domains issuing a
> HVMOP_request_vm_event.  Perhaps it doesn't matter too much.

Working on this again, I'm fine with changing the hypercall but looking
at xen.h none of the others strike me as particularly more intuitive
than __HYPERVISOR_hvm_op. Could you please suggest one that you think
fits the bill?


Thanks,
Razvan