Re: [PATCH 3/4] target/ppc: Add stubs for tcg functions, so it builds

[David Gibson]

On Fri, Apr 09, 2021 at 12:19:15PM -0300, Bruno Larsen (billionai) wrote:
> This file basically adds all stubs required to build the project
> with disable-tcg. most of these are not going to remain stubs by the
> end, but this part is where it got complicated, and I wanted to get
> an RFC ASAP. Most of these have to do with mmu emulation, so they'll
> probably be replaced by a KVM implementation in the final product,
> but I'm not sure which ones have to be replace, which can remain
> stubs, and which should not be called at all. Input in general is
> very much welcome.
> 
> Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
> ---
>  target/ppc/tcg-stub.c | 139 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 139 insertions(+)
>  create mode 100644 target/ppc/tcg-stub.c
> 
> diff --git a/target/ppc/tcg-stub.c b/target/ppc/tcg-stub.c
> new file mode 100644
> index 0000000000..5dc8cf8911
> --- /dev/null
> +++ b/target/ppc/tcg-stub.c
> @@ -0,0 +1,139 @@
> +#include "qemu/osdep.h"
> +#include "cpu.h"
> +#include "mmu-hash64.h"
> +
> +/* STUFF FOR FIRST LINKER ERROR */
> +/* This stuff happens in target/ppc files */
> +
> +#if !defined(CONFIG_USER_ONLY)
> +
> +void ppc_store_sdr1(CPUPPCState *env, target_ulong value) {

In general stubbing ppc_store_*() functions doesn't look seem like a
good idea.  At the very least the KVM code will need to update the
register in env so that it gets synced with KVM later.  I think you're
going to be better off moving those ppc_store_*() functions used from
KVM code into somewhere common, then #ifdefing to remove any TCG
specific operations from them (or else providing KVM stubs for the TCG
things they call).

> +    /* stub to make things compile */
> +    return;
> +}
> +
> +void ppc_store_ptcr(CPUPPCState *env, target_ulong value) {
> +    /* stub to make things compile */
> +    return;
> +}
> +
> +#endif /* !defined(CONFIG_USER_ONLY) */
> +void ppc_store_msr(CPUPPCState *env, target_ulong value) {
> +    /* stub to make things compile */
> +    return;
> +}
> +
> +void dump_mmu(CPUPPCState *env){
> +    /* stub to make things compile */
> +    return;
> +}
> +
> +void store_fpscr(CPUPPCState *env, uint64_t arg, uint32_t mask) {
> +    /* stub to make things compile */
> +    return;
> +}
> +
> +void ppc_cpu_do_interrupt(CPUState *cpu) {
> +    /* stub to make things compile */
> +    return;
> +}
> +
> +/* STUFF FOR SECOND LINKER ERROR*/
> +/* these errors happen mostly in hw/ppc */
> +
> +#ifdef TARGET_PPC64
> +int ppc_store_slb(PowerPCCPU *cpu, target_ulong slot,
> +                  target_ulong esid, target_ulong vsid) {
> +    /* rquired by kvm.c and machine.c */
> +    return 0;
> +}
> +
> +void ppc_hash64_filter_pagesizes(PowerPCCPU *cpu,
> +                                 bool (*cb)(void *, uint32_t, uint32_t),
> +                                 void *opaque) {
> +    /* required by spapr_caps.c */
> +    return; 
> +}
> +
> +void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val) {
> +    /* required by spapr_* */
> +    return;
> +}
> +
> +const ppc_hash_pte64_t *ppc_hash64_map_hptes(PowerPCCPU *cpu,
> +                                             hwaddr ptex, int n) {
> +    /* used by spapr_hcall a bunch */
> +    return NULL;
> +}
> +
> +void ppc_hash64_unmap_hptes(PowerPCCPU *cpu, const ppc_hash_pte64_t *hptes,
> +                            hwaddr ptex, int n) {
> +    /* used a bunch by spapr_hcall */
> +    return; 
> +}
> +
> +void ppc_hash64_tlb_flush_hpte(PowerPCCPU *cpu,
> +                               target_ulong pte_index,
> +                               target_ulong pte0, target_ulong pte1){
> +    return; 
> +}
> +
> +unsigned ppc_hash64_hpte_page_shift_noslb(PowerPCCPU *cpu,
> +                                          uint64_t pte0, uint64_t pte1) {
> +    return 0;
> +}
> +#endif
> +
> +void ppc_cpu_do_fwnmi_machine_check(CPUState *cs, target_ulong vector) {
> +    /* required by spapr_events spapr_mce_dispatch_elog */
> +    return;
> +}
> +#ifndef CONFIG_USER_ONLY
> +void ppc_cpu_do_system_reset(CPUState *cs){
> +    /* required by pnv and spapr */
> +    return;
> +}
> +#endif
> +
> +bool ppc64_v3_get_pate(PowerPCCPU *cpu, target_ulong lpid,
> +                       ppc_v3_pate_t *entry);
> +
> +bool ppc64_v3_get_pate(PowerPCCPU *cpu, target_ulong lpid,
> +                       ppc_v3_pate_t *entry) {
> +    /* used by spapr_hcall: ppc_hash64_hpt_mask */
> +    return true;
> +}
> +
> +/* THIRD BATCH OF ERRORS, AFTER MOVING STUFF FROM TRANSLATE TO CPU.C */
> +
> +/* they are all coming from cpu.c, probably */
> +
> +void create_ppc_opcodes(PowerPCCPU *cpu, Error **errp) {
> +    return;
> +}
> +
> +void init_ppc_proc(PowerPCCPU *cpu) {
> +    return;
> +}
> +
> +void destroy_ppc_opcodes(PowerPCCPU *cpu) {
> +    return;
> +}
> +
> +void ppc_tlb_invalidate_all(CPUPPCState *env) {
> +    return;
> +}
> +
> +void ppc_cpu_dump_state(CPUState *cpu, FILE *f, int flags) {
> +    return;
> +}
> +
> +void ppc_cpu_dump_statistics(CPUState *cpu, int flags) {
> +    return;
> +}
> +
> +#include "exec/hwaddr.h"
> +
> +hwaddr ppc_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr) {
> +    return 0;
> +}

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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