Re: [PATCH 2/5] ppc: spapr: cleanup h_enter_nested() with helper routines.

[Fabiano Rosas]

Harsh Prateek Bora <harshpb@linux.ibm.com> writes:

> h_enter_nested() currently does a lot of register specific operations
> which should be abstracted logically to simplify the code for better
> readability. This patch breaks down relevant blocks into respective
> helper routines to make use of them for better readability/maintenance.
>
> Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
> ---
>  hw/ppc/spapr_hcall.c | 99 +++++++++++++++++++++++++++-----------------
>  1 file changed, 60 insertions(+), 39 deletions(-)
>
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 124cee5e53..a13e5256ab 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -1544,6 +1544,62 @@ static target_ulong h_copy_tofrom_guest(PowerPCCPU 
> *cpu,
>      return H_FUNCTION;
>  }
>  
> +static void restore_hdec_from_hvstate(CPUPPCState *dst,
> +                                      struct kvmppc_hv_guest_state *hv_state,
> +                                      target_ulong now)
> +{
> +    target_ulong hdec;

add a blank line here

> +    assert(hv_state);
> +    hdec = hv_state->hdec_expiry - now;
> +    cpu_ppc_hdecr_init(dst);
> +    cpu_ppc_store_hdecr(dst, hdec);
> +}
> +
> +static void restore_lpcr_from_hvstate(PowerPCCPU *cpu,
> +                                      struct kvmppc_hv_guest_state *hv_state)
> +{
> +    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> +    CPUPPCState *dst = &cpu->env;
> +    target_ulong lpcr, lpcr_mask;

here as well

> +    assert(hv_state);
> +    lpcr_mask = LPCR_DPFD | LPCR_ILE | LPCR_AIL | LPCR_LD | LPCR_MER;
> +    lpcr = (dst->spr[SPR_LPCR] & ~lpcr_mask) | (hv_state->lpcr & lpcr_mask);
> +    lpcr |= LPCR_HR | LPCR_UPRT | LPCR_GTSE | LPCR_HVICE | LPCR_HDICE;
> +    lpcr &= ~LPCR_LPES0;
> +    dst->spr[SPR_LPCR] = lpcr & pcc->lpcr_mask;
> +}
> +
> +static void restore_env_from_ptregs_hvstate(CPUPPCState *env,

Take a look at how the kernel does it. It might be better to have ptregs
and hv regs separate. Also probably better to have some terms specific
to the domain (l2 state, l1 state, etc).

> +                                            struct kvmppc_pt_regs *regs,
> +                                            struct kvmppc_hv_guest_state 
> *hv_state)
> +{
> +    assert(env);
> +    assert(regs);
> +    assert(hv_state);
> +    assert(sizeof(env->gpr) == sizeof(regs->gpr));
> +    memcpy(env->gpr, regs->gpr, sizeof(env->gpr));
> +    env->nip = regs->nip;
> +    env->msr = regs->msr;
> +    env->lr = regs->link;
> +    env->ctr = regs->ctr;
> +    cpu_write_xer(env, regs->xer);
> +    ppc_store_cr(env, regs->ccr);
> +    /* hv_state->amor is not used in api v1 */

That's not really an API thing. More of an oversight.

> +    env->spr[SPR_HFSCR] = hv_state->hfscr;
> +    /* TCG does not implement DAWR*, CIABR, PURR, SPURR, IC, VTB, HEIR SPRs*/
> +    env->cfar = hv_state->cfar;
> +    env->spr[SPR_PCR]      = hv_state->pcr;
> +    env->spr[SPR_DPDES]     = hv_state->dpdes;
> +    env->spr[SPR_SRR0]      = hv_state->srr0;
> +    env->spr[SPR_SRR1]      = hv_state->srr1;
> +    env->spr[SPR_SPRG0]     = hv_state->sprg[0];
> +    env->spr[SPR_SPRG1]     = hv_state->sprg[1];
> +    env->spr[SPR_SPRG2]     = hv_state->sprg[2];
> +    env->spr[SPR_SPRG3]     = hv_state->sprg[3];
> +    env->spr[SPR_BOOKS_PID] = hv_state->pidr;
> +    env->spr[SPR_PPR]       = hv_state->ppr;

I would advise against the extra spacing inside functions.