Re: [RFC v3 2/6] xen/arm: Add save/restore support for ARM GIC V2

[Julien Grall <julien.grall@linaro.org>]

Hi,

On 09/05/14 15:24, Ian Campbell wrote:
> On Fri, 2014-05-09 at 09:12 -0500, Wei Huang wrote:
>> On 05/08/2014 05:47 PM, Andrew Cooper wrote:
>>>> +DECLARE_HVM_SAVE_TYPE(GICH_V2, 3, struct hvm_arm_gich_v2);
>>>> +
>>>>    /*
>>>>     * Largest type-code in use
>>>>     */
>>>> -#define HVM_SAVE_CODE_MAX 1
>>>> +#define HVM_SAVE_CODE_MAX 3
>>>>
>>>>    #endif
>>>>
>>>
>>> On x86, we require that HVM save records only contain architectural
>>> state.  Not knowing arm myself, it is not clear from your comments
>>> whether this is the case or not.  Can you confirm whether it is or not?
>> Most states are guest architecture states which include core registers,
>> arch timer, memory. GIC states are arguable, given that Xen uses data
>> structures (e.g. struct vgic_irq_rank) to represent GIC states internally.
>
> (note: I've not looked at this series for ages, I plan to look at this
> new version next week)
>
> The contents of vgic_irq_rank is still a set of architectural register,
> I think (the rank thing is just to account for the fact that some
> registers use 1 bit to describe 32-registers, some use 2 bits to
> describe 16, etc).

Correct, the vgic_irq_rank should be saved entirely. It represents the 
guest view of the GIC state (such as the priorities, the routing... of 
an IRQ).

Regards,

-- 
Julien Grall