Re: [PATCH] Documentation/kvm : Add documentation on Hypercalls

[Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>]

On 08/01/2012 11:55 PM, Marcelo Tosatti wrote:
> On Wed, Aug 01, 2012 at 04:19:01PM +0530, Raghavendra K T wrote:
>> On 08/01/2012 08:37 AM, Marcelo Tosatti wrote:
>>> On Tue, Jul 24, 2012 at 02:23:59PM +0530, Raghavendra K T wrote:
>>>> From: Raghavendra K T<raghavendra.kt@linux.vnet.ibm.com>
>>>>
>>>> Thanks Alex for KVM_HC_FEATURES inputs and Jan for VAPIC_POLL_IRQ,
>>>> and Peter (HPA) for suggesting hypercall ABI addition.
>>>>
>>>> Signed-off-by: Raghavendra K T<raghavendra.kt@linux.vnet.ibm.com>
>>>> ---
[...]
>>>> +
>>>> + Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
>>>> + The hypercall number should be placed in rax and the return value will be
>>>> + placed in rax.  No other registers will be clobbered unless explicitly stated
>>>> + by the particular hypercall.
>>>
>>> It depends on the hypercall. It happens that current hypercalls use
>>> the four registers, but its not an ABI (hyper-v hypercalls uses r8, for example).
>>>
>>
>> Okay, agree. I did not know about hyper-v. Above one is for X86 and
>> KVM  (and not X86 / hyper-v). So I should remove ABI and probably say,
>
> Just say "Linux x86 Hypercall", yeah.
>

Ok, Thanks Marcelo.will respin patches with the changes you suggested.

Also I would  like add Alex's description on ppc hypercalls
into Documentation/virtual/kvm/ppc-pv.txt with Alex from/sob or
suggested-by in a separate patch unless I see any objection to that.