diff options
| -rw-r--r-- | arch/powerpc/kernel/process.c | 16 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 7 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 8 |
3 files changed, 24 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index febe9f7cda2f..2a6fadde58b4 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1250,15 +1250,17 @@ struct task_struct *__switch_to(struct task_struct *prev, restore_math(current->thread.regs); /* - * The copy-paste buffer can only store into foreign real - * addresses, so unprivileged processes can not see the - * data or use it in any way unless they have foreign real - * mappings. If the new process has the foreign real address - * mappings, we must issue a cp_abort to clear any state and - * prevent snooping, corruption or a covert channel. + * On POWER9 the copy-paste buffer can only paste into + * foreign real addresses, so unprivileged processes can not + * see the data or use it in any way unless they have + * foreign real mappings. If the new process has the foreign + * real address mappings, we must issue a cp_abort to clear + * any state and prevent snooping, corruption or a covert + * channel. ISA v3.1 supports paste into local memory. */ if (current->mm && - atomic_read(¤t->mm->context.vas_windows)) + (cpu_has_feature(CPU_FTR_ARCH_31) || + atomic_read(¤t->mm->context.vas_windows))) asm volatile(PPC_CP_ABORT); } #endif /* CONFIG_PPC_BOOK3S_64 */ diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 4ba06a2a306c..3bd3118c7633 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3530,6 +3530,13 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit, */ asm volatile("eieio; tlbsync; ptesync"); + /* + * cp_abort is required if the processor supports local copy-paste + * to clear the copy buffer that was under control of the guest. + */ + if (cpu_has_feature(CPU_FTR_ARCH_31)) + asm volatile(PPC_CP_ABORT); + mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid); /* restore host LPID */ isync(); diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 799d6d0f4ead..cd9995ee8441 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1831,6 +1831,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_RADIX_PREFETCH_BUG) #endif /* CONFIG_PPC_RADIX_MMU */ /* + * cp_abort is required if the processor supports local copy-paste + * to clear the copy buffer that was under control of the guest. + */ +BEGIN_FTR_SECTION + PPC_CP_ABORT +END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31) + + /* * POWER7/POWER8 guest -> host partition switch code. * We don't have to lock against tlbies but we do * have to coordinate the hardware threads. |