On Thu, 2017-02-16 at 16:03 +1100, Paul Mackerras wrote:
> On POWER9, since commit cc3d2940133d ("powerpc/64: Enable use of
> radix
> MMU under hypervisor on POWER9", 2017-01-30), we set both the radix
> and
> HPT bits in the client-architecture-support (CAS) vector, which tells
> the hypervisor that we can do either radix or HPT. According to
> PAPR,
> if we use this combination we are promising to do a
> H_REGISTER_PROC_TBL
> hcall later on to let the hypervisor know whether we are doing radix
> or HPT. We currently do this call if we are doing radix but not if
> we are doing HPT. If the hypervisor is able to support both radix
> and HPT guests, it would be entitled to defer allocation of the HPT
> until the H_REGISTER_PROC_TBL call, and to fail any attempts to
> create
> HPTEs until the H_REGISTER_PROC_TBL call. Thus we need to do a
> H_REGISTER_PROC_TBL call when we are doing HPT; otherwise we may
> crash at boot time.
>
> This adds the code to call H_REGISTER_PROC_TBL in this case, before
> we attempt to create any HPT entries using H_ENTER.
>
> Fixes: cc3d2940133d ("powerpc/64: Enable use of radix MMU under
> hypervisor on POWER9")
> Signed-off-by: Paul Mackerras <pau...@ozlabs.org>
> ---
> This needs to go in after the topic/ppc-kvm branch.
>
> arch/powerpc/mm/hash_utils_64.c | 6 ++++++
> arch/powerpc/platforms/pseries/lpar.c | 8 ++++++--
> 2 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/mm/hash_utils_64.c
> b/arch/powerpc/mm/hash_utils_64.c
> index 8033493..b0ed96e 100644
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -839,6 +839,12 @@ static void __init htab_initialize(void)
> /* Using a hypervisor which owns the htab */
> htab_address = NULL;
> _SDR1 = 0;
> + /*
> + * On POWER9, we need to do a H_REGISTER_PROC_TBL
> hcall
> + * to inform the hypervisor that we wish to use the
> HPT.
> + */
> + if (cpu_has_feature(CPU_FTR_ARCH_300))
> + register_process_table(0, 0, 0);
> #ifdef CONFIG_FA_DUMP
> /*
> * If firmware assisted dump is active firmware
> preserves
> diff --git a/arch/powerpc/platforms/pseries/lpar.c
> b/arch/powerpc/platforms/pseries/lpar.c
> index 0587655..5b47026 100644
> --- a/arch/powerpc/platforms/pseries/lpar.c
> +++ b/arch/powerpc/platforms/pseries/lpar.c
> @@ -609,15 +609,18 @@ static int __init disable_bulk_remove(char
> *str)
>
> __setup("bulk_remove=", disable_bulk_remove);
>
> -/* Actually only used for radix, so far */
> static int pseries_lpar_register_process_table(unsigned long base,
> unsigned long page_size, unsigned long
> table_size)
> {
> long rc;
> - unsigned long flags = PROC_TABLE_NEW;
> + unsigned long flags = 0;
>
> + if (table_size)
> + flags |= PROC_TABLE_NEW;
> if (radix_enabled())
> flags |= PROC_TABLE_RADIX | PROC_TABLE_GTSE;
> + else
> + flags |= PROC_TABLE_HPT_SLB;
> for (;;) {
> rc = plpar_hcall_norets(H_REGISTER_PROC_TBL, flags,
> base,
> page_size, table_size);
> @@ -643,6 +646,7 @@ void __init hpte_init_pseries(void)
> mmu_hash_ops.flush_hash_range =
> pSeries_lpar_flush_hash_range;
> mmu_hash_ops.hpte_clear_all = pseries_hpte_clear_all;
> mmu_hash_ops.hugepage_invalidate =
> pSeries_lpar_hugepage_invalidate;
> + register_process_table =
> pseries_lpar_register_process_table;
> }
>
> void radix_init_pseries(void)
FWIW:
Reviewed-by: Suraj Jitindar Singh <sjitindarsi...@gmail.com>
