diff options
| -rw-r--r-- | arch/arm/include/asm/kvm_asm.h | 2 | ||||
| -rw-r--r-- | arch/arm/include/asm/kvm_mmu.h | 12 | ||||
| -rw-r--r-- | arch/arm/kvm/mmu.c | 153 | ||||
| -rw-r--r-- | arch/arm/kvm/trace.h | 26 |
4 files changed, 192 insertions, 1 deletions
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h index f6652f6c5d84..5e06e8177784 100644 --- a/arch/arm/include/asm/kvm_asm.h +++ b/arch/arm/include/asm/kvm_asm.h @@ -71,6 +71,8 @@ extern char __kvm_hyp_vector[]; extern char __kvm_hyp_code_start[]; extern char __kvm_hyp_code_end[]; +extern void __kvm_tlb_flush_vmid(struct kvm *kvm); + extern void __kvm_flush_vm_context(void); extern void __kvm_tlb_flush_vmid(struct kvm *kvm); diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 499e7b0925ff..421a20b34874 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -35,4 +35,16 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu); phys_addr_t kvm_mmu_get_httbr(void); int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); + +static inline bool kvm_is_write_fault(unsigned long hsr) +{ + unsigned long hsr_ec = hsr >> HSR_EC_SHIFT; + if (hsr_ec == HSR_EC_IABT) + return false; + else if ((hsr & HSR_ISV) && !(hsr & HSR_WNR)) + return false; + else + return true; +} + #endif /* __ARM_KVM_MMU_H__ */ diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 4347d68f052f..a4b7b0f900e5 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -21,9 +21,11 @@ #include <linux/io.h> #include <asm/idmap.h> #include <asm/pgalloc.h> +#include <asm/cacheflush.h> #include <asm/kvm_arm.h> #include <asm/kvm_mmu.h> #include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> #include <asm/mach/map.h> #include <trace/events/kvm.h> @@ -488,9 +490,158 @@ out: return ret; } +static void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn) +{ + /* + * If we are going to insert an instruction page and the icache is + * either VIPT or PIPT, there is a potential problem where the host + * (or another VM) may have used the same page as this guest, and we + * read incorrect data from the icache. If we're using a PIPT cache, + * we can invalidate just that page, but if we are using a VIPT cache + * we need to invalidate the entire icache - damn shame - as written + * in the ARM ARM (DDI 0406C.b - Page B3-1393). + * + * VIVT caches are tagged using both the ASID and the VMID and doesn't + * need any kind of flushing (DDI 0406C.b - Page B3-1392). + */ + if (icache_is_pipt()) { + unsigned long hva = gfn_to_hva(kvm, gfn); + __cpuc_coherent_user_range(hva, hva + PAGE_SIZE); + } else if (!icache_is_vivt_asid_tagged()) { + /* any kind of VIPT cache */ + __flush_icache_all(); + } +} + +static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, + gfn_t gfn, struct kvm_memory_slot *memslot, + unsigned long fault_status) +{ + pte_t new_pte; + pfn_t pfn; + int ret; + bool write_fault, writable; + unsigned long mmu_seq; + struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; + + write_fault = kvm_is_write_fault(vcpu->arch.hsr); + if (fault_status == FSC_PERM && !write_fault) { + kvm_err("Unexpected L2 read permission error\n"); + return -EFAULT; + } + + /* We need minimum second+third level pages */ + ret = mmu_topup_memory_cache(memcache, 2, KVM_NR_MEM_OBJS); + if (ret) + return ret; + + mmu_seq = vcpu->kvm->mmu_notifier_seq; + /* + * Ensure the read of mmu_notifier_seq happens before we call + * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk + * the page we just got a reference to gets unmapped before we have a + * chance to grab the mmu_lock, which ensure that if the page gets + * unmapped afterwards, the call to kvm_unmap_hva will take it away + * from us again properly. This smp_rmb() interacts with the smp_wmb() + * in kvm_mmu_notifier_invalidate_<page|range_end>. + */ + smp_rmb(); + + pfn = gfn_to_pfn_prot(vcpu->kvm, gfn, write_fault, &writable); + if (is_error_pfn(pfn)) + return -EFAULT; + + new_pte = pfn_pte(pfn, PAGE_S2); + coherent_icache_guest_page(vcpu->kvm, gfn); + + spin_lock(&vcpu->kvm->mmu_lock); + if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) + goto out_unlock; + if (writable) { + pte_val(new_pte) |= L_PTE_S2_RDWR; + kvm_set_pfn_dirty(pfn); + } + stage2_set_pte(vcpu->kvm, memcache, fault_ipa, &new_pte, false); + +out_unlock: + spin_unlock(&vcpu->kvm->mmu_lock); + kvm_release_pfn_clean(pfn); + return 0; +} + +/** + * kvm_handle_guest_abort - handles all 2nd stage aborts + * @vcpu: the VCPU pointer + * @run: the kvm_run structure + * + * Any abort that gets to the host is almost guaranteed to be caused by a + * missing second stage translation table entry, which can mean that either the + * guest simply needs more memory and we must allocate an appropriate page or it + * can mean that the guest tried to access I/O memory, which is emulated by user + * space. The distinction is based on the IPA causing the fault and whether this + * memory region has been registered as standard RAM by user space. + */ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) { - return -EINVAL; + unsigned long hsr_ec; + unsigned long fault_status; + phys_addr_t fault_ipa; + struct kvm_memory_slot *memslot; + bool is_iabt; + gfn_t gfn; + int ret, idx; + + hsr_ec = vcpu->arch.hsr >> HSR_EC_SHIFT; + is_iabt = (hsr_ec == HSR_EC_IABT); + fault_ipa = ((phys_addr_t)vcpu->arch.hpfar & HPFAR_MASK) << 8; + + trace_kvm_guest_fault(*vcpu_pc(vcpu), vcpu->arch.hsr, + vcpu->arch.hxfar, fault_ipa); + + /* Check the stage-2 fault is trans. fault or write fault */ + fault_status = (vcpu->arch.hsr & HSR_FSC_TYPE); + if (fault_status != FSC_FAULT && fault_status != FSC_PERM) { + kvm_err("Unsupported fault status: EC=%#lx DFCS=%#lx\n", + hsr_ec, fault_status); + return -EFAULT; + } + + idx = srcu_read_lock(&vcpu->kvm->srcu); + + gfn = fault_ipa >> PAGE_SHIFT; + if (!kvm_is_visible_gfn(vcpu->kvm, gfn)) { + if (is_iabt) { + /* Prefetch Abort on I/O address */ + kvm_inject_pabt(vcpu, vcpu->arch.hxfar); + ret = 1; + goto out_unlock; + } + + if (fault_status != FSC_FAULT) { + kvm_err("Unsupported fault status on io memory: %#lx\n", + fault_status); + ret = -EFAULT; + goto out_unlock; + } + + kvm_pr_unimpl("I/O address abort..."); + ret = 0; + goto out_unlock; + } + + memslot = gfn_to_memslot(vcpu->kvm, gfn); + if (!memslot->user_alloc) { + kvm_err("non user-alloc memslots not supported\n"); + ret = -EINVAL; + goto out_unlock; + } + + ret = user_mem_abort(vcpu, fault_ipa, gfn, memslot, fault_status); + if (ret == 0) + ret = 1; +out_unlock: + srcu_read_unlock(&vcpu->kvm->srcu, idx); + return ret; } static void handle_hva_to_gpa(struct kvm *kvm, diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h index 022305b38c27..624b5a4e8fad 100644 --- a/arch/arm/kvm/trace.h +++ b/arch/arm/kvm/trace.h @@ -39,6 +39,32 @@ TRACE_EVENT(kvm_exit, TP_printk("PC: 0x%08lx", __entry->vcpu_pc) ); +TRACE_EVENT(kvm_guest_fault, + TP_PROTO(unsigned long vcpu_pc, unsigned long hsr, + unsigned long hxfar, + unsigned long long ipa), + TP_ARGS(vcpu_pc, hsr, hxfar, ipa), + + TP_STRUCT__entry( + __field( unsigned long, vcpu_pc ) + __field( unsigned long, hsr ) + __field( unsigned long, hxfar ) + __field( unsigned long long, ipa ) + ), + + TP_fast_assign( + __entry->vcpu_pc = vcpu_pc; + __entry->hsr = hsr; + __entry->hxfar = hxfar; + __entry->ipa = ipa; + ), + + TP_printk("guest fault at PC %#08lx (hxfar %#08lx, " + "ipa %#16llx, hsr %#08lx", + __entry->vcpu_pc, __entry->hxfar, + __entry->ipa, __entry->hsr) +); + TRACE_EVENT(kvm_irq_line, TP_PROTO(unsigned int type, int vcpu_idx, int irq_num, int level), TP_ARGS(type, vcpu_idx, irq_num, level), |