Merge git://github.com/rustyrussell/linux

* git://github.com/rustyrussell/linux:
  virtio-pci: make reset operation safer
  virtio-mmio: Correct the name of the guest features selector
  virtio: add HAS_IOMEM dependency to MMIO platform bus driver

drivers/virtio/Kconfig

@@ -37,7 +37,7 @@ config VIRTIO_BALLOON
 
  config VIRTIO_MMIO
  	tristate "Platform bus driver for memory mapped virtio devices (EXPERIMENTAL)"
- 	depends on EXPERIMENTAL
+ 	depends on HAS_IOMEM && EXPERIMENTAL
  	select VIRTIO
  	select VIRTIO_RING
  	---help---

drivers/virtio/virtio_mmio.c

@@ -118,7 +118,7 @@ static void vm_finalize_features(struct virtio_device *vdev)
 	vring_transport_features(vdev);
 
 	for (i = 0; i < ARRAY_SIZE(vdev->features); i++) {
-		writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SET);
+		writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
 		writel(vdev->features[i],
 				vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
 	}

drivers/virtio/virtio_pci.c

@@ -169,11 +169,29 @@ static void vp_set_status(struct virtio_device *vdev, u8 status)
 	iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
 }
 
+/* wait for pending irq handlers */
+static void vp_synchronize_vectors(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+	int i;
+
+	if (vp_dev->intx_enabled)
+		synchronize_irq(vp_dev->pci_dev->irq);
+
+	for (i = 0; i < vp_dev->msix_vectors; ++i)
+		synchronize_irq(vp_dev->msix_entries[i].vector);
+}
+
 static void vp_reset(struct virtio_device *vdev)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 	/* 0 status means a reset. */
 	iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+	/* Flush out the status write, and flush in device writes,
+	 * including MSi-X interrupts, if any. */
+	ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+	/* Flush pending VQ/configuration callbacks. */
+	vp_synchronize_vectors(vdev);
 }
 
 /* the notify function used when creating a virt queue */

include/linux/virtio_config.h

@@ -85,6 +85,8 @@
  * @reset: reset the device
  *	vdev: the virtio device
  *	After this, status and feature negotiation must be done again
+ *	Device must not be reset from its vq/config callbacks, or in
+ *	parallel with being added/removed.
  * @find_vqs: find virtqueues and instantiate them.
  *	vdev: the virtio_device
  *	nvqs: the number of virtqueues to find

include/linux/virtio_mmio.h

@@ -63,7 +63,7 @@
 #define VIRTIO_MMIO_GUEST_FEATURES	0x020
 
 /* Activated features set selector - Write Only */
-#define VIRTIO_MMIO_GUEST_FEATURES_SET	0x024
+#define VIRTIO_MMIO_GUEST_FEATURES_SEL	0x024
 
 /* Guest's memory page size in bytes - Write Only */
 #define VIRTIO_MMIO_GUEST_PAGE_SIZE	0x028