On 06/01/2026 2:26 pm, Jan Beulich wrote:
> On 06.01.2026 15:19, Oleksii Kurochko wrote:
>>>> + struct
>>>> + {
>>>> + register_t s0;
>>>> + register_t s1;
>>>> + register_t s2;
>>>> + register_t s3;
>>>> + register_t s4;
>>>> + register_t s5;
>>>> + register_t s6;
>>>> + register_t s7;
>>>> + register_t s8;
>>>> + register_t s9;
>>>> + register_t s10;
>>>> + register_t s11;
>>>> +
>>>> + register_t sp;
>>>> + register_t gp;
>>>> +
>>>> + /* ra is used to jump to guest when creating new vcpu */
>>>> + register_t ra;
>>>> + } xen_saved_context;
>>> The xen_ prefix here also doesn't exist in Arm code.
>> I think it should be added for Arm too. I can send a patch.
> ... this, to reword my comment: What value does the xen_ prefix add?
This was my recommendation after reverse engineering how ARM worked to
explain it to Oleksii. But I also thought I said to write a real
comment too.
This is arbitrary *Xen* state, not guest state like you'd expect to find
in struct vcpu. The guest GPR state is at the base of the vCPU stack.
I suggested that this property be made clearer for the benefit of anyone
trying to decipher the context switching logic.
~Andrew
