virtio/vhost: fixes and cleanups for 4.8

- Misc fixes and cleanups all over the place.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio/vhost fixes and cleanups from Michael Tsirkin:
 "Misc fixes and cleanups all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio/s390: deprecate old transport
  virtio/s390: keep early_put_chars
  virtio_blk: Fix a slient kernel panic
  virtio-vsock: fix include guard typo
  vhost/vsock: fix vhost virtio_vsock_pkt use-after-free
  9p/trans_virtio: use kvfree() for iov_iter_get_pages_alloc()
  virtio: fix error handling for debug builds
  virtio: fix memory leak in virtqueue_add()

arch/s390/Kconfig

@@ -872,4 +872,17 @@ config S390_GUEST
 	  Select this option if you want to run the kernel as a guest under
 	  the KVM hypervisor.
 
+config S390_GUEST_OLD_TRANSPORT
+	def_bool y
+	prompt "Guest support for old s390 virtio transport (DEPRECATED)"
+	depends on S390_GUEST
+	help
+	  Enable this option to add support for the old s390-virtio
+	  transport (i.e. virtio devices NOT based on virtio-ccw). This
+	  type of virtio devices is only available on the experimental
+	  kuli userspace or with old (< 2.6) qemu. If you are running
+	  with a modern version of qemu (which supports virtio-ccw since
+	  1.4 and uses it by default since version 2.4), you probably won't
+	  need this.
+
 endmenu

drivers/block/virtio_blk.c

@@ -391,23 +391,17 @@ static int init_vq(struct virtio_blk *vblk)
 		num_vqs = 1;
 
 	vblk->vqs = kmalloc(sizeof(*vblk->vqs) * num_vqs, GFP_KERNEL);
-	if (!vblk->vqs) {
+	if (!vblk->vqs)
+		return -ENOMEM;
+
+	names = kmalloc(sizeof(*names) * num_vqs, GFP_KERNEL);
+	callbacks = kmalloc(sizeof(*callbacks) * num_vqs, GFP_KERNEL);
+	vqs = kmalloc(sizeof(*vqs) * num_vqs, GFP_KERNEL);
+	if (!names || !callbacks || !vqs) {
 		err = -ENOMEM;
 		goto out;
 	}
 
-	names = kmalloc(sizeof(*names) * num_vqs, GFP_KERNEL);
-	if (!names)
-		goto err_names;
-
-	callbacks = kmalloc(sizeof(*callbacks) * num_vqs, GFP_KERNEL);
-	if (!callbacks)
-		goto err_callbacks;
-
-	vqs = kmalloc(sizeof(*vqs) * num_vqs, GFP_KERNEL);
-	if (!vqs)
-		goto err_vqs;
-
 	for (i = 0; i < num_vqs; i++) {
 		callbacks[i] = virtblk_done;
 		snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
@@ -417,7 +411,7 @@ static int init_vq(struct virtio_blk *vblk)
 	/* Discover virtqueues and write information to configuration.  */
 	err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
 	if (err)
-		goto err_find_vqs;
+		goto out;
 
 	for (i = 0; i < num_vqs; i++) {
 		spin_lock_init(&vblk->vqs[i].lock);
@@ -425,16 +419,12 @@ static int init_vq(struct virtio_blk *vblk)
 	}
 	vblk->num_vqs = num_vqs;
 
- err_find_vqs:
+out:
 	kfree(vqs);
- err_vqs:
 	kfree(callbacks);
- err_callbacks:
 	kfree(names);
- err_names:
 	if (err)
 		kfree(vblk->vqs);
- out:
 	return err;
 }
 

drivers/s390/virtio/Makefile

@@ -6,4 +6,8 @@
 # it under the terms of the GNU General Public License (version 2 only)
 # as published by the Free Software Foundation.
 
-obj-$(CONFIG_S390_GUEST) += kvm_virtio.o virtio_ccw.o
+s390-virtio-objs := virtio_ccw.o
+ifdef CONFIG_S390_GUEST_OLD_TRANSPORT
+s390-virtio-objs += kvm_virtio.o
+endif
+obj-$(CONFIG_S390_GUEST) += $(s390-virtio-objs)

drivers/s390/virtio/kvm_virtio.c

@@ -458,6 +458,8 @@ static int __init kvm_devices_init(void)
 	if (test_devices_support(total_memory_size) < 0)
 		return -ENODEV;
 
+	pr_warn("The s390-virtio transport is deprecated. Please switch to a modern host providing virtio-ccw.\n");
+
 	rc = vmem_add_mapping(total_memory_size, PAGE_SIZE);
 	if (rc)
 		return rc;
@@ -482,7 +484,7 @@ static int __init kvm_devices_init(void)
 }
 
 /* code for early console output with virtio_console */
-static __init int early_put_chars(u32 vtermno, const char *buf, int count)
+static int early_put_chars(u32 vtermno, const char *buf, int count)
 {
 	char scratch[17];
 	unsigned int len = count;

drivers/vhost/vsock.c

@@ -307,6 +307,8 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
 
 	vhost_disable_notify(&vsock->dev, vq);
 	for (;;) {
+		u32 len;
+
 		if (!vhost_vsock_more_replies(vsock)) {
 			/* Stop tx until the device processes already
 			 * pending replies.  Leave tx virtqueue
@@ -334,13 +336,15 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
 			continue;
 		}
 
+		len = pkt->len;
+
 		/* Only accept correctly addressed packets */
 		if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
 			virtio_transport_recv_pkt(pkt);
 		else
 			virtio_transport_free_pkt(pkt);
 
-		vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
+		vhost_add_used(vq, head, sizeof(pkt->hdr) + len);
 		added = true;
 	}
 

drivers/virtio/virtio_ring.c

@@ -327,6 +327,8 @@ static inline int virtqueue_add(struct virtqueue *_vq,
 		 * host should service the ring ASAP. */
 		if (out_sgs)
 			vq->notify(&vq->vq);
+		if (indirect)
+			kfree(desc);
 		END_USE(vq);
 		return -ENOSPC;
 	}
@@ -426,6 +428,7 @@ unmap_release:
 	if (indirect)
 		kfree(desc);
 
+	END_USE(vq);
 	return -EIO;
 }
 

include/uapi/linux/virtio_vsock.h

@@ -32,7 +32,7 @@
  */
 
 #ifndef _UAPI_LINUX_VIRTIO_VSOCK_H
-#define _UAPI_LINUX_VIRTIO_VOSCK_H
+#define _UAPI_LINUX_VIRTIO_VSOCK_H
 
 #include <linux/types.h>
 #include <linux/virtio_ids.h>

net/9p/trans_virtio.c

@@ -507,8 +507,8 @@ err_out:
 		/* wakeup anybody waiting for slots to pin pages */
 		wake_up(&vp_wq);
 	}
-	kfree(in_pages);
-	kfree(out_pages);
+	kvfree(in_pages);
+	kvfree(out_pages);
 	return err;
 }