diff --git a/include/kvm/pci.h b/include/kvm/pci.h
index 2c29c09..0f0815b 100644
--- a/include/kvm/pci.h
+++ b/include/kvm/pci.h
@@ -5,6 +5,7 @@
 #include <linux/kvm.h>
 #include <linux/pci_regs.h>
 #include <endian.h>
+#include <stdbool.h>
 
 #include "kvm/devices.h"
 #include "kvm/msi.h"
@@ -161,4 +162,56 @@
 
 void *pci_find_cap(struct pci_device_header *hdr, u8 cap_type);
 
+static inline bool __pci__memory_space_enabled(u16 command)
+{
+	return command & PCI_COMMAND_MEMORY;
+}
+
+static inline bool pci__memory_space_enabled(struct pci_device_header *pci_hdr)
+{
+	return __pci__memory_space_enabled(pci_hdr->command);
+}
+
+static inline bool __pci__io_space_enabled(u16 command)
+{
+	return command & PCI_COMMAND_IO;
+}
+
+static inline bool pci__io_space_enabled(struct pci_device_header *pci_hdr)
+{
+	return __pci__io_space_enabled(pci_hdr->command);
+}
+
+static inline bool __pci__bar_is_io(u32 bar)
+{
+	return bar & PCI_BASE_ADDRESS_SPACE_IO;
+}
+
+static inline bool pci__bar_is_io(struct pci_device_header *pci_hdr, int bar_num)
+{
+	return __pci__bar_is_io(pci_hdr->bar[bar_num]);
+}
+
+static inline bool pci__bar_is_memory(struct pci_device_header *pci_hdr, int bar_num)
+{
+	return !pci__bar_is_io(pci_hdr, bar_num);
+}
+
+static inline u32 __pci__bar_address(u32 bar)
+{
+	if (__pci__bar_is_io(bar))
+		return bar & PCI_BASE_ADDRESS_IO_MASK;
+	return bar & PCI_BASE_ADDRESS_MEM_MASK;
+}
+
+static inline u32 pci__bar_address(struct pci_device_header *pci_hdr, int bar_num)
+{
+	return __pci__bar_address(pci_hdr->bar[bar_num]);
+}
+
+static inline u32 pci__bar_size(struct pci_device_header *pci_hdr, int bar_num)
+{
+	return pci_hdr->bar_size[bar_num];
+}
+
 #endif /* KVM__PCI_H */
diff --git a/pci.c b/pci.c
index 3ecdd0f..81e9cec 100644
--- a/pci.c
+++ b/pci.c
@@ -185,7 +185,7 @@
 	 * size, it will write the address back.
 	 */
 	if (bar < 6) {
-		if (pci_hdr->bar[bar] & PCI_BASE_ADDRESS_SPACE_IO)
+		if (pci__bar_is_io(pci_hdr, bar))
 			mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
 		else
 			mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
@@ -211,7 +211,7 @@
 		 */
 		memcpy(&value, data, size);
 		if (value == 0xffffffff)
-			value = ~(pci_hdr->bar_size[bar] - 1);
+			value = ~(pci__bar_size(pci_hdr, bar) - 1);
 		/* Preserve the special bits. */
 		value = (value & mask) | (pci_hdr->bar[bar] & ~mask);
 		memcpy(base + offset, &value, size);
diff --git a/powerpc/spapr_pci.c b/powerpc/spapr_pci.c
index a15f7d8..7be44d9 100644
--- a/powerpc/spapr_pci.c
+++ b/powerpc/spapr_pci.c
@@ -369,7 +369,7 @@
 				of_pci_b_ddddd(devid) |
 				of_pci_b_fff(fn) |
 				of_pci_b_rrrrrrrr(bars[i]));
-			reg[n+1].size = cpu_to_be64(hdr->bar_size[i]);
+			reg[n+1].size = cpu_to_be64(pci__bar_size(hdr, i));
 			reg[n+1].addr = 0;
 
 			assigned_addresses[n].phys_hi = cpu_to_be32(