diff options
| -rw-r--r-- | arch/powerpc/include/asm/mmu_context.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 21 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_p9_entry.c | 14 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 34 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s64/radix_pgtable.c | 27 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s64/radix_tlb.c | 46 | ||||
| -rw-r--r-- | arch/powerpc/mm/mmu_context.c | 4 |
7 files changed, 34 insertions, 118 deletions
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 4bc45d3ed8b0..84e192aa54fd 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -122,12 +122,6 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea) } #endif -#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU) -extern void radix_kvm_prefetch_workaround(struct mm_struct *mm); -#else -static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { } -#endif - extern void switch_cop(struct mm_struct *next); extern int use_cop(unsigned long acop, struct mm_struct *mm); extern void drop_cop(unsigned long acop, struct mm_struct *mm); diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 12c35b0561d3..eb25605e23b9 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -807,7 +807,8 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags, * KVM does not support mflags=2 (AIL=2) and AIL=1 is reserved. * Keep this in synch with kvmppc_filter_guest_lpcr_hv. */ - if (mflags != 0 && mflags != 3) + if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) && + kvmhv_vcpu_is_radix(vcpu) && mflags == 3) return H_UNSUPPORTED_FLAG_START; return H_TOO_HARD; default: @@ -1677,6 +1678,14 @@ unsigned long kvmppc_filter_lpcr_hv(struct kvm *kvm, unsigned long lpcr) lpcr &= ~LPCR_AIL; if ((lpcr & LPCR_AIL) != LPCR_AIL_3) lpcr &= ~LPCR_AIL; /* LPCR[AIL]=1/2 is disallowed */ + /* + * On some POWER9s we force AIL off for radix guests to prevent + * executing in MSR[HV]=1 mode with the MMU enabled and PIDR set to + * guest, which can result in Q0 translations with LPID=0 PID=PIDR to + * be cached, which the host TLB management does not expect. + */ + if (kvm_is_radix(kvm) && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) + lpcr &= ~LPCR_AIL; /* * On POWER9, allow userspace to enable large decrementer for the @@ -4360,12 +4369,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu) vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST; do { - /* - * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu - * path, which also handles hash and dependent threads mode. - */ - if (kvm->arch.threads_indep && kvm_is_radix(kvm) && - !cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) + if (kvm->arch.threads_indep && kvm_is_radix(kvm)) r = kvmhv_run_single_vcpu(vcpu, ~(u64)0, vcpu->arch.vcore->lpcr); else @@ -4995,6 +4999,9 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm) if (!indep_threads_mode && !cpu_has_feature(CPU_FTR_HVMODE)) { pr_warn("KVM: Ignoring indep_threads_mode=N in nested hypervisor\n"); kvm->arch.threads_indep = true; + } else if (!indep_threads_mode && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) { + pr_warn("KVM: Ignoring indep_threads_mode=N on pre-DD2.2 POWER9\n"); + kvm->arch.threads_indep = true; } else { kvm->arch.threads_indep = indep_threads_mode; } diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c index 0b5bd00c9d0f..178f771e299c 100644 --- a/arch/powerpc/kvm/book3s_hv_p9_entry.c +++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c @@ -218,6 +218,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc mtspr(SPRN_AMOR, ~0UL); + if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) + __mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0); + switch_mmu_to_guest_radix(kvm, vcpu, lpcr); /* @@ -226,7 +229,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc */ mtspr(SPRN_HDEC, hdec); - __mtmsrd(0, 1); /* clear RI */ + if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) + __mtmsrd(0, 1); /* clear RI */ mtspr(SPRN_DAR, vcpu->arch.shregs.dar); mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr); @@ -341,8 +345,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc radix_clear_slb(); - __mtmsrd(msr, 0); - accumulate_time(vcpu, &vcpu->arch.rm_exit); /* Advance host PURR/SPURR by the amount used by guest */ @@ -408,6 +410,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc switch_mmu_to_host_radix(kvm, host_pidr); + /* + * If we are in real mode, only switch MMU on after the MMU is + * switched to host, to avoid the P9_RADIX_PREFETCH_BUG. + */ + __mtmsrd(msr, 0); + end_timing(vcpu); return trap; diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index d742233dec55..3b8fd4bd2419 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1717,40 +1717,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300) eieio tlbsync ptesync - -BEGIN_FTR_SECTION - /* Radix: Handle the case where the guest used an illegal PID */ - LOAD_REG_ADDR(r4, mmu_base_pid) - lwz r3, VCPU_GUEST_PID(r9) - lwz r5, 0(r4) - cmpw cr0,r3,r5 - blt 2f - - /* - * Illegal PID, the HW might have prefetched and cached in the TLB - * some translations for the LPID 0 / guest PID combination which - * Linux doesn't know about, so we need to flush that PID out of - * the TLB. First we need to set LPIDR to 0 so tlbiel applies to - * the right context. - */ - li r0,0 - mtspr SPRN_LPID,r0 - isync - - /* Then do a congruence class local flush */ - ld r6,VCPU_KVM(r9) - lwz r0,KVM_TLB_SETS(r6) - mtctr r0 - li r7,0x400 /* IS field = 0b01 */ - ptesync - sldi r0,r3,32 /* RS has PID */ -1: PPC_TLBIEL(7,0,2,1,1) /* RIC=2, PRS=1, R=1 */ - addi r7,r7,0x1000 - bdnz 1b - ptesync -END_FTR_SECTION_IFSET(CPU_FTR_P9_RADIX_PREFETCH_BUG) - -2: #endif /* CONFIG_PPC_RADIX_MMU */ /* diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c index 5fef8db3b463..fe236c38ce00 100644 --- a/arch/powerpc/mm/book3s64/radix_pgtable.c +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -357,30 +357,19 @@ static void __init radix_init_pgtable(void) } /* Find out how many PID bits are supported */ - if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) { - if (!mmu_pid_bits) - mmu_pid_bits = 20; - mmu_base_pid = 1; - } else if (cpu_has_feature(CPU_FTR_HVMODE)) { - if (!mmu_pid_bits) - mmu_pid_bits = 20; -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + if (!cpu_has_feature(CPU_FTR_HVMODE) && + cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) { /* - * When KVM is possible, we only use the top half of the - * PID space to avoid collisions between host and guest PIDs - * which can cause problems due to prefetch when exiting the - * guest with AIL=3 + * Older versions of KVM on these machines perfer if the + * guest only uses the low 19 PID bits. */ - mmu_base_pid = 1 << (mmu_pid_bits - 1); -#else - mmu_base_pid = 1; -#endif - } else { - /* The guest uses the bottom half of the PID space */ if (!mmu_pid_bits) mmu_pid_bits = 19; - mmu_base_pid = 1; + } else { + if (!mmu_pid_bits) + mmu_pid_bits = 20; } + mmu_base_pid = 1; /* * Allocate Partition table and process table for the diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c index 409e61210789..312236a6b085 100644 --- a/arch/powerpc/mm/book3s64/radix_tlb.c +++ b/arch/powerpc/mm/book3s64/radix_tlb.c @@ -1336,49 +1336,3 @@ void radix__flush_tlb_all(void) : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(0) : "memory"); asm volatile("eieio; tlbsync; ptesync": : :"memory"); } - -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE -extern void radix_kvm_prefetch_workaround(struct mm_struct *mm) -{ - unsigned long pid = mm->context.id; - - if (unlikely(pid == MMU_NO_CONTEXT)) - return; - - if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) - return; - - /* - * If this context hasn't run on that CPU before and KVM is - * around, there's a slim chance that the guest on another - * CPU just brought in obsolete translation into the TLB of - * this CPU due to a bad prefetch using the guest PID on - * the way into the hypervisor. - * - * We work around this here. If KVM is possible, we check if - * any sibling thread is in KVM. If it is, the window may exist - * and thus we flush that PID from the core. - * - * A potential future improvement would be to mark which PIDs - * have never been used on the system and avoid it if the PID - * is new and the process has no other cpumask bit set. - */ - if (cpu_has_feature(CPU_FTR_HVMODE) && radix_enabled()) { - int cpu = smp_processor_id(); - int sib = cpu_first_thread_sibling(cpu); - bool flush = false; - - for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) { - if (sib == cpu) - continue; - if (!cpu_possible(sib)) - continue; - if (paca_ptrs[sib]->kvm_hstate.kvm_vcpu) - flush = true; - } - if (flush) - _tlbiel_pid(pid, RIC_FLUSH_ALL); - } -} -EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround); -#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */ diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c index a857af401738..74246536b832 100644 --- a/arch/powerpc/mm/mmu_context.c +++ b/arch/powerpc/mm/mmu_context.c @@ -83,9 +83,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, if (cpu_has_feature(CPU_FTR_ALTIVEC)) asm volatile ("dssall"); - if (new_on_cpu) - radix_kvm_prefetch_workaround(next); - else + if (!new_on_cpu) membarrier_arch_switch_mm(prev, next, tsk); /* |