From: James Hogan Date: Fri, 17 Jan 2014 12:01:31 +0000 (+0000) Subject: MIPS: KVM: remove shadow_tlb code X-Git-Tag: firefly_0821_release~176^2~4513^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=08596b0a757824df775cac0f4fa06975f578d3b2;p=firefly-linux-kernel-4.4.55.git MIPS: KVM: remove shadow_tlb code The kvm_mips_init_shadow_tlb() function is called from kvm_arch_vcpu_init() and initialises entries 0 to current_cpu_data.tlbsize-1 of the virtual cpu's shadow_tlb[64] array. However newer cores with FTLBs can have a tlbsize > 64, for example the ProAptiv I'm testing on has a total tlbsize of 576. This causes kvm_mips_init_shadow_tlb() to overflow the shadow_tlb[64] array and overwrite the comparecount_timer among other things, causing a lock up when starting a KVM guest. Aside from kvm_mips_init_shadow_tlb() which only initialises it, the shadow_tlb[64] array is only actually used by the following functions: - kvm_shadow_tlb_put() & kvm_shadow_tlb_load() These are never called. The only call sites are #if 0'd out. - kvm_mips_dump_shadow_tlbs() This is never called. It was originally added for trap & emulate, but turned out to be unnecessary so it was disabled. So instead of fixing the shadow_tlb initialisation code, lets just remove the shadow_tlb[64] array and the above functions entirely. The only functional change here is the removal of broken shadow_tlb initialisation. The rest just deletes dead code. Signed-off-by: James Hogan Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: Gleb Natapov Cc: kvm@vger.kernel.org Cc: Sanjay Lal Acked-by: Paolo Bonzini Signed-off-by: John Crispin Patchwork: http://patchwork.linux-mips.org/patch/6384/ --- diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h index 32966969f2f9..a995fce87791 100644 --- a/arch/mips/include/asm/kvm_host.h +++ b/arch/mips/include/asm/kvm_host.h @@ -391,9 +391,6 @@ struct kvm_vcpu_arch { uint32_t guest_kernel_asid[NR_CPUS]; struct mm_struct guest_kernel_mm, guest_user_mm; - struct kvm_mips_tlb shadow_tlb[NR_CPUS][KVM_MIPS_GUEST_TLB_SIZE]; - - struct hrtimer comparecount_timer; int last_sched_cpu; @@ -529,7 +526,6 @@ extern enum emulation_result kvm_mips_handle_tlbmod(unsigned long cause, extern void kvm_mips_dump_host_tlbs(void); extern void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu); -extern void kvm_mips_dump_shadow_tlbs(struct kvm_vcpu *vcpu); extern void kvm_mips_flush_host_tlb(int skip_kseg0); extern int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long entryhi); extern int kvm_mips_host_tlb_inv_index(struct kvm_vcpu *vcpu, int index); @@ -541,10 +537,7 @@ extern unsigned long kvm_mips_translate_guest_kseg0_to_hpa(struct kvm_vcpu *vcpu unsigned long gva); extern void kvm_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu, struct kvm_vcpu *vcpu); -extern void kvm_shadow_tlb_put(struct kvm_vcpu *vcpu); -extern void kvm_shadow_tlb_load(struct kvm_vcpu *vcpu); extern void kvm_local_flush_tlb_all(void); -extern void kvm_mips_init_shadow_tlb(struct kvm_vcpu *vcpu); extern void kvm_mips_alloc_new_mmu_context(struct kvm_vcpu *vcpu); extern void kvm_mips_vcpu_load(struct kvm_vcpu *vcpu, int cpu); extern void kvm_mips_vcpu_put(struct kvm_vcpu *vcpu); diff --git a/arch/mips/kvm/kvm_mips.c b/arch/mips/kvm/kvm_mips.c index 73b34827826c..da5186fbd77a 100644 --- a/arch/mips/kvm/kvm_mips.c +++ b/arch/mips/kvm/kvm_mips.c @@ -1001,7 +1001,6 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) hrtimer_init(&vcpu->arch.comparecount_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); vcpu->arch.comparecount_timer.function = kvm_mips_comparecount_wakeup; - kvm_mips_init_shadow_tlb(vcpu); return 0; } diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c index 52083ea7fddd..68e6563915cd 100644 --- a/arch/mips/kvm/kvm_tlb.c +++ b/arch/mips/kvm/kvm_tlb.c @@ -145,30 +145,6 @@ void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu) } } -void kvm_mips_dump_shadow_tlbs(struct kvm_vcpu *vcpu) -{ - int i; - volatile struct kvm_mips_tlb tlb; - - printk("Shadow TLBs:\n"); - for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) { - tlb = vcpu->arch.shadow_tlb[smp_processor_id()][i]; - printk("TLB%c%3d Hi 0x%08lx ", - (tlb.tlb_lo0 | tlb.tlb_lo1) & MIPS3_PG_V ? ' ' : '*', - i, tlb.tlb_hi); - printk("Lo0=0x%09" PRIx64 " %c%c attr %lx ", - (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo0), - (tlb.tlb_lo0 & MIPS3_PG_D) ? 'D' : ' ', - (tlb.tlb_lo0 & MIPS3_PG_G) ? 'G' : ' ', - (tlb.tlb_lo0 >> 3) & 7); - printk("Lo1=0x%09" PRIx64 " %c%c attr %lx sz=%lx\n", - (uint64_t) mips3_tlbpfn_to_paddr(tlb.tlb_lo1), - (tlb.tlb_lo1 & MIPS3_PG_D) ? 'D' : ' ', - (tlb.tlb_lo1 & MIPS3_PG_G) ? 'G' : ' ', - (tlb.tlb_lo1 >> 3) & 7, tlb.tlb_mask); - } -} - static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn) { int srcu_idx, err = 0; @@ -655,70 +631,6 @@ kvm_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu, cpu_context(cpu, mm) = asid_cache(cpu) = asid; } -void kvm_shadow_tlb_put(struct kvm_vcpu *vcpu) -{ - unsigned long flags; - unsigned long old_entryhi; - unsigned long old_pagemask; - int entry = 0; - int cpu = smp_processor_id(); - - local_irq_save(flags); - - old_entryhi = read_c0_entryhi(); - old_pagemask = read_c0_pagemask(); - - for (entry = 0; entry < current_cpu_data.tlbsize; entry++) { - write_c0_index(entry); - mtc0_tlbw_hazard(); - tlb_read(); - tlbw_use_hazard(); - - vcpu->arch.shadow_tlb[cpu][entry].tlb_hi = read_c0_entryhi(); - vcpu->arch.shadow_tlb[cpu][entry].tlb_lo0 = read_c0_entrylo0(); - vcpu->arch.shadow_tlb[cpu][entry].tlb_lo1 = read_c0_entrylo1(); - vcpu->arch.shadow_tlb[cpu][entry].tlb_mask = read_c0_pagemask(); - } - - write_c0_entryhi(old_entryhi); - write_c0_pagemask(old_pagemask); - mtc0_tlbw_hazard(); - - local_irq_restore(flags); - -} - -void kvm_shadow_tlb_load(struct kvm_vcpu *vcpu) -{ - unsigned long flags; - unsigned long old_ctx; - int entry; - int cpu = smp_processor_id(); - - local_irq_save(flags); - - old_ctx = read_c0_entryhi(); - - for (entry = 0; entry < current_cpu_data.tlbsize; entry++) { - write_c0_entryhi(vcpu->arch.shadow_tlb[cpu][entry].tlb_hi); - mtc0_tlbw_hazard(); - write_c0_entrylo0(vcpu->arch.shadow_tlb[cpu][entry].tlb_lo0); - write_c0_entrylo1(vcpu->arch.shadow_tlb[cpu][entry].tlb_lo1); - - write_c0_index(entry); - mtc0_tlbw_hazard(); - - tlb_write_indexed(); - tlbw_use_hazard(); - } - - tlbw_use_hazard(); - write_c0_entryhi(old_ctx); - mtc0_tlbw_hazard(); - local_irq_restore(flags); -} - - void kvm_local_flush_tlb_all(void) { unsigned long flags; @@ -747,30 +659,6 @@ void kvm_local_flush_tlb_all(void) local_irq_restore(flags); } -void kvm_mips_init_shadow_tlb(struct kvm_vcpu *vcpu) -{ - int cpu, entry; - - for_each_possible_cpu(cpu) { - for (entry = 0; entry < current_cpu_data.tlbsize; entry++) { - vcpu->arch.shadow_tlb[cpu][entry].tlb_hi = - UNIQUE_ENTRYHI(entry); - vcpu->arch.shadow_tlb[cpu][entry].tlb_lo0 = 0x0; - vcpu->arch.shadow_tlb[cpu][entry].tlb_lo1 = 0x0; - vcpu->arch.shadow_tlb[cpu][entry].tlb_mask = - read_c0_pagemask(); -#ifdef DEBUG - kvm_debug - ("shadow_tlb[%d][%d]: tlb_hi: %#lx, lo0: %#lx, lo1: %#lx\n", - cpu, entry, - vcpu->arch.shadow_tlb[cpu][entry].tlb_hi, - vcpu->arch.shadow_tlb[cpu][entry].tlb_lo0, - vcpu->arch.shadow_tlb[cpu][entry].tlb_lo1); -#endif - } - } -} - /* Restore ASID once we are scheduled back after preemption */ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { @@ -808,14 +696,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id); } - /* Only reload shadow host TLB if new ASIDs haven't been allocated */ -#if 0 - if ((atomic_read(&kvm_mips_instance) > 1) && !newasid) { - kvm_mips_flush_host_tlb(0); - kvm_shadow_tlb_load(vcpu); - } -#endif - if (!newasid) { /* If we preempted while the guest was executing, then reload the pre-empted ASID */ if (current->flags & PF_VCPU) { @@ -861,12 +741,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) vcpu->arch.preempt_entryhi = read_c0_entryhi(); vcpu->arch.last_sched_cpu = cpu; -#if 0 - if ((atomic_read(&kvm_mips_instance) > 1)) { - kvm_shadow_tlb_put(vcpu); - } -#endif - if (((cpu_context(cpu, current->mm) ^ asid_cache(cpu)) & ASID_VERSION_MASK)) { kvm_debug("%s: Dropping MMU Context: %#lx\n", __func__, @@ -928,10 +802,8 @@ uint32_t kvm_get_inst(uint32_t *opc, struct kvm_vcpu *vcpu) } EXPORT_SYMBOL(kvm_local_flush_tlb_all); -EXPORT_SYMBOL(kvm_shadow_tlb_put); EXPORT_SYMBOL(kvm_mips_handle_mapped_seg_tlb_fault); EXPORT_SYMBOL(kvm_mips_handle_commpage_tlb_fault); -EXPORT_SYMBOL(kvm_mips_init_shadow_tlb); EXPORT_SYMBOL(kvm_mips_dump_host_tlbs); EXPORT_SYMBOL(kvm_mips_handle_kseg0_tlb_fault); EXPORT_SYMBOL(kvm_mips_host_tlb_lookup); @@ -939,8 +811,6 @@ EXPORT_SYMBOL(kvm_mips_flush_host_tlb); EXPORT_SYMBOL(kvm_mips_guest_tlb_lookup); EXPORT_SYMBOL(kvm_mips_host_tlb_inv); EXPORT_SYMBOL(kvm_mips_translate_guest_kseg0_to_hpa); -EXPORT_SYMBOL(kvm_shadow_tlb_load); -EXPORT_SYMBOL(kvm_mips_dump_shadow_tlbs); EXPORT_SYMBOL(kvm_mips_dump_guest_tlbs); EXPORT_SYMBOL(kvm_get_inst); EXPORT_SYMBOL(kvm_arch_vcpu_load);