bypass_mmio.diff

? diff
Index: sys/arch/amd64/amd64/vmm.c
===================================================================
RCS file: /cvs/src/sys/arch/amd64/amd64/vmm.c,v
retrieving revision 1.254
diff -u -p -r1.254 vmm.c
--- sys/arch/amd64/amd64/vmm.c	22 Sep 2019 08:47:54 -0000	1.254
+++ sys/arch/amd64/amd64/vmm.c	19 Oct 2019 15:38:42 -0000
@@ -168,6 +168,7 @@ int vmx_handle_cr4_write(struct vcpu *, 
 int vmx_handle_cr(struct vcpu *);
 int svm_handle_inout(struct vcpu *);
 int vmx_handle_inout(struct vcpu *);
+int vmx_handle_mmio(struct vcpu *);
 int svm_handle_hlt(struct vcpu *);
 int vmx_handle_hlt(struct vcpu *);
 int vmm_inject_ud(struct vcpu *);
@@ -4885,6 +4886,9 @@ vmx_handle_exit(struct vcpu *vcpu)
 		break;
 	case VMX_EXIT_EPT_VIOLATION:
 		ret = vmx_handle_np_fault(vcpu);
+		if (ret == EAGAIN) { /* XXX: mmio */
+			update_rip = 1;
+		}
 		break;
 	case VMX_EXIT_CPUID:
 		ret = vmm_handle_cpuid(vcpu);
@@ -5065,7 +5069,7 @@ vmm_get_guest_memtype(struct vm *vm, pad
 
 	if (gpa >= VMM_PCI_MMIO_BAR_BASE && gpa <= VMM_PCI_MMIO_BAR_END) {
 		DPRINTF("guest mmio access @ 0x%llx\n", (uint64_t)gpa);
-		return (VMM_MEM_TYPE_REGULAR);
+		return (VMM_MEM_TYPE_MMIO);
 	}
 
 	/* XXX Use binary search? */
@@ -5263,6 +5267,11 @@ vmx_handle_np_fault(struct vcpu *vcpu)
 	case VMM_MEM_TYPE_REGULAR:
 		ret = vmx_fault_page(vcpu, gpa);
 		break;
+	case VMM_MEM_TYPE_MMIO: /* XXX: wip */
+		printf("mmio %d for GPA 0x%llx\n",
+		    gpa_memtype, gpa);
+		ret = vmx_handle_mmio(vcpu);
+		break;
 	default:
 		printf("unknown memory type %d for GPA 0x%llx\n",
 		    gpa_memtype, gpa);
@@ -5564,6 +5573,52 @@ vmx_handle_inout(struct vcpu *vcpu)
 	}
 
 	return (ret);
+}
+
+/*
+ * vmx_handle_mmio
+ *
+ * Exit handler for memory accesses to PCI MMIO region.
+ *
+ * Currently, this simply ignore and skip the instruction.
+ */
+int
+vmx_handle_mmio(struct vcpu *vcpu)
+{
+	uint64_t insn_length, exit_qual;
+	// paddr_t insn_hpa, insn_gpa;
+
+	/* skip this mmio access */
+	if (vmread(VMCS_INSTRUCTION_LENGTH, &insn_length)) {
+		printf("%s: can't obtain instruction length\n", __func__);
+		return (EINVAL);
+	}
+
+	if (vmx_get_exit_qualification(&exit_qual)) {
+		printf("%s: can't get exit qual\n", __func__);
+		return (EINVAL);
+	}
+
+	// insn_gpa = vcpu->vc_gueststate.vg_rip;
+
+	/* XXX
+	if (!pmap_extract(vcpu->vc_parent->vm_map->pmap, insn_gpa, &insn_hpa)) {
+		DPRINTF("%s: nonmapped guest rip %lx\n", __func__, insn_gpa);
+		return (EINVAL);
+	}
+
+
+	printf("mmio hello:\n\tinstn: %4x %4x %4x %4x\n\tlength: %lld\n",
+			*(((uint16_t*) insn_gpa)),
+			*(((uint16_t*) insn_gpa) + 1),
+			*(((uint16_t*) insn_gpa) + 2),
+			*(((uint16_t*) insn_gpa) + 3),
+			insn_length);
+	*/
+
+	vcpu->vc_gueststate.vg_rip += insn_length;
+
+	return (EAGAIN);
 }
 
 /*