@@ -331,6 +331,8 @@
 
 /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
 #define HPFAR_MASK	(~UL(0xf))
+
+#define FAR_MASK GENMASK_ULL(11, 0)
 /*
  * We have
  *	PAR	[PA_Shift - 1	: 12] = PA	[PA_Shift - 1 : 12]

@@ -8,6 +8,7 @@
 struct kvm_iommu_ops {
 	int (*init)(void);
 	void (*host_stage2_idmap)(phys_addr_t start, phys_addr_t end, int prot);
+	bool (*dabt_handler)(struct user_pt_regs *regs, u64 esr, u64 addr);
 };
 
 int kvm_iommu_init(void *pool_base, size_t nr_pages);

@@ -16,5 +17,5 @@ void kvm_iommu_host_stage2_idmap(phys_addr_t start, phys_addr_t end,
 				 enum kvm_pgtable_prot prot);
 void *kvm_iommu_donate_pages(u8 order);
 void kvm_iommu_reclaim_pages(void *ptr);
-
+bool kvm_iommu_host_dabt_handler(struct user_pt_regs *regs, u64 esr, u64 addr);
 #endif /* __ARM64_KVM_NVHE_IOMMU_H__ */

@@ -4,6 +4,10 @@
  *
  * Copyright (C) 2022 Linaro Ltd.
  */
+#include <asm/kvm_hyp.h>
+
+#include <hyp/adjust_pc.h>
+
 #include <linux/iommu.h>
 
 #include <nvhe/iommu.h>

@@ -113,3 +117,14 @@ void kvm_iommu_reclaim_pages(void *ptr)
 {
 	hyp_put_page(&iommu_pages_pool, ptr);
 }
+
+bool kvm_iommu_host_dabt_handler(struct user_pt_regs *regs, u64 esr, u64 addr)
+{
+	if (kvm_iommu_ops && kvm_iommu_ops->dabt_handler &&
+	    kvm_iommu_ops->dabt_handler(regs, esr, addr)) {
+		/* DABT handled by the driver, skip to next instruction. */
+		kvm_skip_host_instr();
+		return true;
+	}
+	return false;
+}

@@ -595,6 +595,11 @@ static int host_stage2_idmap(u64 addr)
 	return ret;
 }
 
+static bool is_dabt(u64 esr)
+{
+	return ESR_ELx_EC(esr) == ESR_ELx_EC_DABT_LOW;
+}
+
 void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)
 {
 	struct kvm_vcpu_fault_info fault;

@@ -617,6 +622,11 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)
 	 */
 	BUG_ON(!(fault.hpfar_el2 & HPFAR_EL2_NS));
 	addr = FIELD_GET(HPFAR_EL2_FIPA, fault.hpfar_el2) << 12;
+	addr |= fault.far_el2 & FAR_MASK;
+
+	if (is_dabt(esr) && !addr_is_memory(addr) &&
+	    kvm_iommu_host_dabt_handler(&host_ctxt->regs, esr, addr))
+		return;
 
 	ret = host_stage2_idmap(addr);
 	BUG_ON(ret && ret != -EAGAIN);