diff --git a/kernel_module/README.md b/kernel_module/README.md
index 3bdf434..8913db3 100644
--- a/kernel_module/README.md
+++ b/kernel_module/README.md
@@ -26,6 +26,7 @@
         1. [dep2](dep2.c)
     1.  [character_device](character_device.c)
     1.  Hardware device drivers
+        1. [pci_min](pci_min.c)
         1. [pci](pci.c)
         1. [platform_device](platform_device.c)
 1.  [user](user/)
diff --git a/kernel_module/pci_min.c b/kernel_module/pci_min.c
index 54481a7..81b9e84 100644
--- a/kernel_module/pci_min.c
+++ b/kernel_module/pci_min.c
@@ -2,6 +2,8 @@
 Only tested in x86.
 
 PCI driver for our minimal pci_min.c QEMU fork device.
+
+probe already does a mmio write, which generates an IRQ and tests everything.
 */
 
 #include <asm/uaccess.h>
diff --git a/kernel_module/platform_device.c b/kernel_module/platform_device.c
index 0776b80..e7972b6 100644
--- a/kernel_module/platform_device.c
+++ b/kernel_module/platform_device.c
@@ -77,8 +77,8 @@ static int lkmc_platform_device_probe(struct platform_device *pdev)
 		dev_err(dev, "of_iomap");
 		return -EINVAL;
 	}
-	dev_info(dev, "res.start = %u resource_size = %llx\n",
-			res.start, (unsigned long long)resource_size(&res));
+	dev_info(dev, "res.start = %llx resource_size = %llx\n",
+			(unsigned long long)res.start, (unsigned long long)resource_size(&res));
 
 	/* Test MMIO and IRQ. */
 	iowrite32(0x12345678, map);
diff --git a/qemu b/qemu
index 577f463..22e7e21 160000
--- a/qemu
+++ b/qemu
@@ -1 +1 @@
-Subproject commit 577f4633f156c263aae9855c2f06328831e05ccd
+Subproject commit 22e7e210d6fbe54c35a5ae32450a4419df25a13b
diff --git a/run b/run
index 348f123..ca73702 100755
--- a/run
+++ b/run
@@ -44,6 +44,7 @@ env \
   HOST_QEMU_OPTS="--enable-debug --enable-sdl --extra-cflags='-DDEBUG_PL061=1' --with-sdlabi=2.0" \
   host-qemu-rebuild \
   linux-rebuild \
+  kernel_module-rebuild \
   all \
 ;
 cd ..
diff --git a/runqemu b/runqemu
index 8351e93..071dcc1 100755
--- a/runqemu
+++ b/runqemu
@@ -63,6 +63,7 @@ case "$arch" in
       -M pc \
       -append 'root=/dev/vda $extra_append' \
       -device edu \
+      -device lkmc_pci_min \
       -drive file=${images_dir}/rootfs.ext2,if=virtio,format=raw \
       -kernel ${images_dir}/bzImage \
       -net nic,model=virtio \