summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--arch/arm/kvm/mmu.c46
-rw-r--r--arch/arm/kvm/trace.h15
2 files changed, 61 insertions, 0 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 1831aa26eef8..56c8b03c0ca1 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -1304,6 +1304,46 @@ out_unlock:
return ret;
}
+/*
+ * Resolve the access fault by making the page young again.
+ * Note that because the faulting entry is guaranteed not to be
+ * cached in the TLB, we don't need to invalidate anything.
+ */
+static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
+{
+ pmd_t *pmd;
+ pte_t *pte;
+ pfn_t pfn;
+ bool pfn_valid = false;
+
+ trace_kvm_access_fault(fault_ipa);
+
+ spin_lock(&vcpu->kvm->mmu_lock);
+
+ pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
+ if (!pmd || pmd_none(*pmd)) /* Nothing there */
+ goto out;
+
+ if (kvm_pmd_huge(*pmd)) { /* THP, HugeTLB */
+ *pmd = pmd_mkyoung(*pmd);
+ pfn = pmd_pfn(*pmd);
+ pfn_valid = true;
+ goto out;
+ }
+
+ pte = pte_offset_kernel(pmd, fault_ipa);
+ if (pte_none(*pte)) /* Nothing there either */
+ goto out;
+
+ *pte = pte_mkyoung(*pte); /* Just a page... */
+ pfn = pte_pfn(*pte);
+ pfn_valid = true;
+out:
+ spin_unlock(&vcpu->kvm->mmu_lock);
+ if (pfn_valid)
+ kvm_set_pfn_accessed(pfn);
+}
+
/**
* kvm_handle_guest_abort - handles all 2nd stage aborts
* @vcpu: the VCPU pointer
@@ -1371,6 +1411,12 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
/* Userspace should not be able to register out-of-bounds IPAs */
VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);
+ if (fault_status == FSC_ACCESS) {
+ handle_access_fault(vcpu, fault_ipa);
+ ret = 1;
+ goto out_unlock;
+ }
+
ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
if (ret == 0)
ret = 1;
diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h
index c09f37faff01..0ec35392d208 100644
--- a/arch/arm/kvm/trace.h
+++ b/arch/arm/kvm/trace.h
@@ -68,6 +68,21 @@ TRACE_EVENT(kvm_guest_fault,
__entry->hxfar, __entry->vcpu_pc)
);
+TRACE_EVENT(kvm_access_fault,
+ TP_PROTO(unsigned long ipa),
+ TP_ARGS(ipa),
+
+ TP_STRUCT__entry(
+ __field( unsigned long, ipa )
+ ),
+
+ TP_fast_assign(
+ __entry->ipa = ipa;
+ ),
+
+ TP_printk("IPA: %lx", __entry->ipa)
+);
+
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),