Excerpts from Nicholas Piggin's message of July 17, 2020 12:08 pm: > Excerpts from Qian Cai's message of July 17, 2020 3:27 am: >> On Fri, Jul 03, 2020 at 11:06:05AM +0530, Bharata B Rao wrote: >>> Hypervisor may choose not to enable Guest Translation Shootdown Enable >>> (GTSE) option for the guest. When GTSE isn't ON, the guest OS isn't >>> permitted to use instructions like tblie and tlbsync directly, but is >>> expected to make hypervisor calls to get the TLB flushed. >>> >>> This series enables the TLB flush routines in the radix code to >>> off-load TLB flushing to hypervisor via the newly proposed hcall >>> H_RPT_INVALIDATE. >>> >>> To easily check the availability of GTSE, it is made an MMU feature. >>> The OV5 handling and H_REGISTER_PROC_TBL hcall are changed to >>> handle GTSE as an optionally available feature and to not assume GTSE >>> when radix support is available. >>> >>> The actual hcall implementation for KVM isn't included in this >>> patchset and will be posted separately. >>> >>> Changes in v3 >>> ============= >>> - Fixed a bug in the hcall wrapper code where we were missing setting >>> H_RPTI_TYPE_NESTED while retrying the failed flush request with >>> a full flush for the nested case. >>> - s/psize_to_h_rpti/psize_to_rpti_pgsize >>> >>> v2: https://lore.kernel.org/linuxppc-dev/20200626131000.5207-1-bharata@xxxxxxxxxxxxx/T/#t >>> >>> Bharata B Rao (2): >>> powerpc/mm: Enable radix GTSE only if supported. >>> powerpc/pseries: H_REGISTER_PROC_TBL should ask for GTSE only if >>> enabled >>> >>> Nicholas Piggin (1): >>> powerpc/mm/book3s64/radix: Off-load TLB invalidations to host when >>> !GTSE >> >> Reverting the whole series fixed random memory corruptions during boot on >> POWER9 PowerNV systems below. > > If I s/mmu_has_feature(MMU_FTR_GTSE)/(1)/g in radix_tlb.c, then the .o > disasm is the same as reverting my patch. > > Feature bits not being set right? PowerNV should be pretty simple, seems > to do the same as FTR_TYPE_RADIX. Might need this fix --- diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index 9cc49f265c86..54c9bcea9d4e 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -163,7 +163,7 @@ static struct ibm_pa_feature { { .pabyte = 0, .pabit = 6, .cpu_features = CPU_FTR_NOEXECUTE }, { .pabyte = 1, .pabit = 2, .mmu_features = MMU_FTR_CI_LARGE_PAGE }, #ifdef CONFIG_PPC_RADIX_MMU - { .pabyte = 40, .pabit = 0, .mmu_features = MMU_FTR_TYPE_RADIX }, + { .pabyte = 40, .pabit = 0, .mmu_features = (MMU_FTR_TYPE_RADIX | MMU_FTR_GTSE) }, #endif { .pabyte = 1, .pabit = 1, .invert = 1, .cpu_features = CPU_FTR_NODSISRALIGN }, { .pabyte = 5, .pabit = 0, .cpu_features = CPU_FTR_REAL_LE,
