Re: [PATCH v4 10/15] spapr: nested: Initialize the GSB elements lookup table.

["Nicholas Piggin" <npiggin@gmail.com>]

On Tue Feb 20, 2024 at 6:36 PM AEST, Harsh Prateek Bora wrote:
> Nested PAPR API provides a standard Guest State Buffer (GSB) format
> with unique IDs for each guest state element for which get/set state is
> supported by the API. Some of the elements are read-only and/or guest-wide.
> Introducing helper routines for state exchange of each of the nested guest
> state elements for which get/set state should be supported by the API.
>

This is doing more than just adding helper routines for the GSB access.

[snip]

> +
>  typedef struct SpaprMachineStateNested {
>      uint64_t ptcr;
>      uint8_t api;
> @@ -16,6 +201,8 @@ typedef struct SpaprMachineStateNested {
>  typedef struct SpaprMachineStateNestedGuest {
>      uint32_t pvr_logical;
>      unsigned long vcpus;
> +    uint64_t parttbl[2];
> +    uint64_t tb_offset;
>      struct SpaprMachineStateNestedGuestVcpu *vcpu;
>  } SpaprMachineStateNestedGuest;
>  
[snip]

>  
>  /*
>   * Register state for entering a nested guest with H_ENTER_NESTED.
> @@ -172,17 +452,40 @@ struct nested_ppc_state {
>      uint64_t sier;
>      uint32_t vscr;
>      uint64_t fpscr;
> +    int64_t dec_expiry_tb;
> +};
> +
> +struct SpaprMachineStateNestedGuestVcpuRunBuf {
> +    uint64_t addr;
> +    uint64_t size;
>  };
>  
>  typedef struct SpaprMachineStateNestedGuestVcpu {
>      bool enabled;
>      struct nested_ppc_state state;
> +    struct SpaprMachineStateNestedGuestVcpuRunBuf runbufin;
> +    struct SpaprMachineStateNestedGuestVcpuRunBuf runbufout;
> +    int64_t tb_offset;
> +    uint64_t hdecr_expiry_tb;
>  } SpaprMachineStateNestedGuestVcpu;

It's adding new fields in existing nested guest state
structures. This should be explained a bit more, split into
another patch, or moved to patches where they get used.

Thanks,
Nick