diff --git a/usr.sbin/bhyve/pci_passthru.h b/usr.sbin/bhyve/pci_passthru.h
--- a/usr.sbin/bhyve/pci_passthru.h
+++ b/usr.sbin/bhyve/pci_passthru.h
@@ -11,6 +11,14 @@
 
 #include "pci_emul.h"
 
+struct passthru_mmio_mapping {
+	vm_paddr_t gpa; /* guest physical address */
+	void *gva;	/* guest virtual address */
+	vm_paddr_t hpa; /* host physical address */
+	void *hva;	/* guest virtual address */
+	vm_paddr_t len;
+};
+
 struct passthru_softc;
 
 typedef int (*cfgread_handler)(struct passthru_softc *sc,
@@ -24,6 +32,8 @@
     int coff, int bytes, uint32_t *rv);
 int passthru_cfgwrite_emulate(struct passthru_softc *sc, struct pci_devinst *pi,
     int coff, int bytes, uint32_t val);
+struct passthru_mmio_mapping *passthru_get_mmio(struct passthru_softc *sc,
+    int num);
 struct pcisel *passthru_get_sel(struct passthru_softc *sc);
 int set_pcir_handler(struct passthru_softc *sc, int reg, int len,
     cfgread_handler rhandler, cfgwrite_handler whandler);
diff --git a/usr.sbin/bhyve/pci_passthru.c b/usr.sbin/bhyve/pci_passthru.c
--- a/usr.sbin/bhyve/pci_passthru.c
+++ b/usr.sbin/bhyve/pci_passthru.c
@@ -78,6 +78,8 @@
 #define MSIX_TABLE_COUNT(ctrl) (((ctrl) & PCIM_MSIXCTRL_TABLE_SIZE) + 1)
 #define MSIX_CAPLEN 12
 
+#define PASSTHRU_MMIO_MAX 2
+
 static int pcifd = -1;
 
 struct passthru_softc {
@@ -94,6 +96,7 @@
 	} psc_msix;
 	struct pcisel psc_sel;
 
+	struct passthru_mmio_mapping psc_mmio_map[PASSTHRU_MMIO_MAX];
 	cfgread_handler psc_pcir_rhandler[PCI_REGMAX + 1];
 	cfgwrite_handler psc_pcir_whandler[PCI_REGMAX + 1];
 };
@@ -660,6 +663,15 @@
 	return (error);
 }
 
+struct passthru_mmio_mapping *
+passthru_get_mmio(struct passthru_softc *sc, int num)
+{
+	assert(sc != NULL);
+	assert(num < PASSTHRU_MMIO_MAX);
+
+	return (&sc->psc_mmio_map[num]);
+}
+
 struct pcisel *
 passthru_get_sel(struct passthru_softc *sc)
 {