Re: [RFC v2 1/6] xen/arm: Save and restore support with hvm context hypercalls

[Wei Huang <w1.huang@samsung.com>]

On 05/13/2014 11:37 AM, Julien Grall wrote:
> On 05/13/2014 05:18 PM, Wei Huang wrote:
>> Given the comments from you and Andrew, I will revise the context struct
>> to the following format. With this, we can get rid of most problems
>> (switch/case/...).
>
> With this solution, you will duplicate code to save/restore the timer.
The code size will be reduced and looks cleaner? Here is the example:

static int hvm_timer_save(struct domain *d, hvm_domain_context_t *h)
{
     struct hvm_arm_timer ctxt;
     struct vcpu *v;
     int rc = 0;

     /* Save the state of vtimer and ptimer */
     for_each_vcpu( d, v )
     {
         /* save phys_timer */
         ctxt.phys_cval = v->arch.phys_timer.cval;
         ctxt.phys_ctl = v->arch.phys_timer.ctl;
         ctxt.phys_vtb_offset = d->arch.phys_timer_base.offset;

         /* save virt_timer */
         ctxt.virt_cval = v->arch.virt_timer.cval;
         ctxt.virt_ctl = v->arch.virt_timer.ctl;
         ctxt.virt_vtb_offset = d->arch.virt_timer_base.offset;

         if ( (rc = hvm_save_entry(TIMER, v->vcpu_id, h, &ctxt)) != 0 )
             return rc;
     }

     return rc;
}

>
>> struct hvm_arm_timer
>> {
>>      /* phys_timer */
>>      uint64_t phys_vtb_offset;
>>      uint64_t phys_cval;
>>      uint32_t phys_ctl;
>
> If I'm not mistaken, you need a 32 bit padding here ...
>
>>
>>      /* virt_timer */
>>      uint64_t virt_vtb_offset;
>>      uint64_t virt_cval;
>>      uint32_t virt_ctl;
>
> ... and here
>
> Regards,
>