On 06/18/2018 08:36 AM, David Gibson wrote:
> The paravirtualized PAPR platform sometimes needs to restrict the guest to
> using only some of the page sizes actually supported by the host's MMU.
> At the moment this is handled in KVM specific code, but for consistency we
> want to apply the same limitations to all accelerators.
>
> This makes a start on this by providing a helper function in the cpu code
> to allow platform code to remove some of the cpu's page size definitions
> via a caller supplied callback.
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
it looks correct.
Reviewed-by: Cédric Le Goater <c...@kaod.org>
Thanks,
C.
> ---
> target/ppc/mmu-hash64.c | 59 +++++++++++++++++++++++++++++++++++++++++
> target/ppc/mmu-hash64.h | 3 +++
> 2 files changed, 62 insertions(+)
>
> diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
> index aa200cba4c..276d9015e7 100644
> --- a/target/ppc/mmu-hash64.c
> +++ b/target/ppc/mmu-hash64.c
> @@ -1166,3 +1166,62 @@ const PPCHash64Options ppc_hash64_opts_POWER7 = {
> },
> }
> };
> +
> +void ppc_hash64_filter_pagesizes(PowerPCCPU *cpu,
> + bool (*cb)(void *, uint32_t, uint32_t),
> + void *opaque)
> +{
> + PPCHash64Options *opts = cpu->hash64_opts;
> + int i;
> + int n = 0;
> + bool ci_largepage = false;
> +
> + assert(opts);
> +
> + n = 0;
> + for (i = 0; i < ARRAY_SIZE(opts->sps); i++) {
> + PPCHash64SegmentPageSizes *sps = &opts->sps[i];
> + int j;
> + int m = 0;
> +
> + assert(n <= i);
> +
> + if (!sps->page_shift) {
> + break;
> + }
> +
> + for (j = 0; j < ARRAY_SIZE(sps->enc); j++) {
> + PPCHash64PageSize *ps = &sps->enc[j];
> +
> + assert(m <= j);
> + if (!ps->page_shift) {
> + break;
> + }
> +
> + if (cb(opaque, sps->page_shift, ps->page_shift)) {
> + if (ps->page_shift >= 16) {
> + ci_largepage = true;
> + }
> + sps->enc[m++] = *ps;
> + }
> + }
> +
> + /* Clear rest of the row */
> + for (j = m; j < ARRAY_SIZE(sps->enc); j++) {
> + memset(&sps->enc[j], 0, sizeof(sps->enc[j]));
> + }
> +
> + if (m) {
> + n++;
> + }
> + }
> +
> + /* Clear the rest of the table */
> + for (i = n; i < ARRAY_SIZE(opts->sps); i++) {
> + memset(&opts->sps[i], 0, sizeof(opts->sps[i]));
> + }
> +
> + if (!ci_largepage) {
> + opts->flags &= ~PPC_HASH64_CI_LARGEPAGE;
> + }
> +}
> diff --git a/target/ppc/mmu-hash64.h b/target/ppc/mmu-hash64.h
> index 53dcec5b93..f11efc9cbc 100644
> --- a/target/ppc/mmu-hash64.h
> +++ b/target/ppc/mmu-hash64.h
> @@ -20,6 +20,9 @@ unsigned ppc_hash64_hpte_page_shift_noslb(PowerPCCPU *cpu,
> void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val);
> void ppc_hash64_init(PowerPCCPU *cpu);
> void ppc_hash64_finalize(PowerPCCPU *cpu);
> +void ppc_hash64_filter_pagesizes(PowerPCCPU *cpu,
> + bool (*cb)(void *, uint32_t, uint32_t),
> + void *opaque);
> #endif
>
> /*
>
