Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio updates from Rusty Russell:
 "No real surprises"

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  MAINTAINERS: add tools/virtio/ under virtio
  tools/virtio: move module license stub to module.h
  virtio: include asm/barrier explicitly
  virtio: VIRTIO_F_ANY_LAYOUT feature
  lguest: fix example launcher compilation for broken glibc headers.
  virtio-net: fix the race between channels setting and refill
  tools/lguest: real barriers.
  tools/lguest: fix missing rmb().
  virtio_balloon: leak_balloon(): only tell host if we got pages deflated
  virtio-pci: fix leaks of msix_affinity_masks
  Fix comment typo "CONFIG_PAE"

MAINTAINERS

@@ -8890,6 +8890,7 @@ M:	"Michael S. Tsirkin" <mst@redhat.com>
 L:	virtualization@lists.linux-foundation.org
 S:	Maintained
 F:	drivers/virtio/
+F:	tools/virtio/
 F:	drivers/net/virtio_net.c
 F:	drivers/block/virtio_blk.c
 F:	include/linux/virtio_*.h

drivers/net/virtio_net.c

@@ -902,7 +902,6 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 	struct scatterlist sg;
 	struct virtio_net_ctrl_mq s;
 	struct net_device *dev = vi->dev;
-	int i;
 
 	if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
 		return 0;
@@ -916,10 +915,8 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
 			 queue_pairs);
 		return -EINVAL;
 	} else {
-		for (i = vi->curr_queue_pairs; i < queue_pairs; i++)
-			if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
-				schedule_delayed_work(&vi->refill, 0);
 		vi->curr_queue_pairs = queue_pairs;
+		schedule_delayed_work(&vi->refill, 0);
 	}
 
 	return 0;

drivers/virtio/virtio_balloon.c

@@ -192,7 +192,8 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num)
 	 * virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST);
 	 * is true, we *have* to do it in this order
 	 */
-	tell_host(vb, vb->deflate_vq);
+	if (vb->num_pfns != 0)
+		tell_host(vb, vb->deflate_vq);
 	mutex_unlock(&vb->balloon_lock);
 	release_pages_by_pfn(vb->pfns, vb->num_pfns);
 }

drivers/virtio/virtio_pci.c

@@ -289,9 +289,9 @@ static void vp_free_vectors(struct virtio_device *vdev)
 
 		pci_disable_msix(vp_dev->pci_dev);
 		vp_dev->msix_enabled = 0;
-		vp_dev->msix_vectors = 0;
 	}
 
+	vp_dev->msix_vectors = 0;
 	vp_dev->msix_used_vectors = 0;
 	kfree(vp_dev->msix_names);
 	vp_dev->msix_names = NULL;
@@ -309,6 +309,8 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
 	unsigned i, v;
 	int err = -ENOMEM;
 
+	vp_dev->msix_vectors = nvectors;
+
 	vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
 				       GFP_KERNEL);
 	if (!vp_dev->msix_entries)
@@ -336,7 +338,6 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
 		err = -ENOSPC;
 	if (err)
 		goto error;
-	vp_dev->msix_vectors = nvectors;
 	vp_dev->msix_enabled = 1;
 
 	/* Set the vector used for configuration */

include/linux/virtio_ring.h

@@ -1,6 +1,7 @@
 #ifndef _LINUX_VIRTIO_RING_H
 #define _LINUX_VIRTIO_RING_H
 
+#include <asm/barrier.h>
 #include <linux/irqreturn.h>
 #include <uapi/linux/virtio_ring.h>
 

include/uapi/linux/virtio_config.h

@@ -51,4 +51,7 @@
  * suppressed them? */
 #define VIRTIO_F_NOTIFY_ON_EMPTY	24
 
+/* Can the device handle any descriptor layout? */
+#define VIRTIO_F_ANY_LAYOUT		27
+
 #endif /* _UAPI_LINUX_VIRTIO_CONFIG_H */

tools/lguest/Makefile

@@ -1,5 +1,4 @@
 # This creates the demonstration utility "lguest" which runs a Linux guest.
-# Missing headers?  Add "-I../../../include -I../../../arch/x86/include"
 CFLAGS:=-m32 -Wall -Wmissing-declarations -Wmissing-prototypes -O3 -U_FORTIFY_SOURCE
 
 all: lguest

tools/lguest/lguest.c

@@ -42,14 +42,6 @@
 #include <pwd.h>
 #include <grp.h>
 
-#include <linux/virtio_config.h>
-#include <linux/virtio_net.h>
-#include <linux/virtio_blk.h>
-#include <linux/virtio_console.h>
-#include <linux/virtio_rng.h>
-#include <linux/virtio_ring.h>
-#include <asm/bootparam.h>
-#include "../../include/linux/lguest_launcher.h"
 /*L:110
  * We can ignore the 43 include files we need for this program, but I do want
  * to draw attention to the use of kernel-style types.
@@ -65,6 +57,15 @@ typedef uint16_t u16;
 typedef uint8_t u8;
 /*:*/
 
+#include <linux/virtio_config.h>
+#include <linux/virtio_net.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_console.h>
+#include <linux/virtio_rng.h>
+#include <linux/virtio_ring.h>
+#include <asm/bootparam.h>
+#include "../../include/linux/lguest_launcher.h"
+
 #define BRIDGE_PFX "bridge:"
 #ifndef SIOCBRADDIF
 #define SIOCBRADDIF	0x89a2		/* add interface to bridge      */
@@ -177,7 +178,8 @@ static struct termios orig_term;
  * in precise order.
  */
 #define wmb() __asm__ __volatile__("" : : : "memory")
-#define mb() __asm__ __volatile__("" : : : "memory")
+#define rmb() __asm__ __volatile__("lock; addl $0,0(%%esp)" : : : "memory")
+#define mb() __asm__ __volatile__("lock; addl $0,0(%%esp)" : : : "memory")
 
 /* Wrapper for the last available index.  Makes it easier to change. */
 #define lg_last_avail(vq)	((vq)->last_avail_idx)
@@ -676,6 +678,12 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq,
 		errx(1, "Guest moved used index from %u to %u",
 		     last_avail, vq->vring.avail->idx);
 
+	/* 
+	 * Make sure we read the descriptor number *after* we read the ring
+	 * update; don't let the cpu or compiler change the order.
+	 */
+	rmb();
+
 	/*
 	 * Grab the next descriptor number they're advertising, and increment
 	 * the index we've seen.
@@ -694,6 +702,12 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq,
 	desc = vq->vring.desc;
 	i = head;
 
+	/*
+	 * We have to read the descriptor after we read the descriptor number,
+	 * but there's a data dependency there so the CPU shouldn't reorder
+	 * that: no rmb() required.
+	 */
+
 	/*
 	 * If this is an indirect entry, then this buffer contains a descriptor
 	 * table which we handle as if it's any normal descriptor chain.

tools/virtio/linux/module.h

@@ -1 +1,6 @@
 #include <linux/export.h>
+
+#define MODULE_LICENSE(__MODULE_LICENSE_value) \
+	static __attribute__((unused)) const char *__MODULE_LICENSE_name = \
+		__MODULE_LICENSE_value
+

tools/virtio/linux/virtio.h

@@ -45,9 +45,6 @@ struct virtqueue {
 	void *priv;
 };
 
-#define MODULE_LICENSE(__MODULE_LICENSE_value) \
-	const char *__MODULE_LICENSE_name = __MODULE_LICENSE_value
-
 /* Interfaces exported by virtio_ring. */
 int virtqueue_add_sgs(struct virtqueue *vq,
 		      struct scatterlist *sgs[],