virtio: tests, fixes and cleanups

Just minor tweaks, there's nothing major in this cycle.
 
 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 updates from Michael Tsirkin:
 "Tests, fixes and cleanups.

  Just minor tweaks, there's nothing major in this cycle"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_ring: mark vring_dma_dev inline
  virtio/vhost: add Jason to list of maintainers
  virtio_blk: Delete an unnecessary initialisation in init_vq()
  virtio_blk: Use kmalloc_array() in init_vq()
  virtio: remove config.c
  virtio: console: Unlock vqs while freeing buffers
  ringtest: poll for new buffers once before updating event index
  ringtest: commonize implementation of poll_avail/poll_used
  ringtest: use link-time optimization
  virtio: update balloon size in balloon "probe"
  virtio_ring: Make interrupt suppression spec compliant
  virtio_pci: Limit DMA mask to 44 bits for legacy virtio devices

MAINTAINERS

@@ -12783,6 +12783,7 @@ F:	include/uapi/linux/virtio_console.h
 
 VIRTIO CORE, NET AND BLOCK DRIVERS
 M:	"Michael S. Tsirkin" <mst@redhat.com>
+M:	Jason Wang <jasowang@redhat.com>
 L:	virtualization@lists.linux-foundation.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/virtio/
@@ -12813,6 +12814,7 @@ F:	include/uapi/linux/virtio_gpu.h
 
 VIRTIO HOST (VHOST)
 M:	"Michael S. Tsirkin" <mst@redhat.com>
+M:	Jason Wang <jasowang@redhat.com>
 L:	kvm@vger.kernel.org
 L:	virtualization@lists.linux-foundation.org
 L:	netdev@vger.kernel.org

drivers/block/virtio_blk.c

@@ -376,7 +376,7 @@ static void virtblk_config_changed(struct virtio_device *vdev)
 
 static int init_vq(struct virtio_blk *vblk)
 {
-	int err = 0;
+	int err;
 	int i;
 	vq_callback_t **callbacks;
 	const char **names;
@@ -390,13 +390,13 @@ static int init_vq(struct virtio_blk *vblk)
 	if (err)
 		num_vqs = 1;
 
-	vblk->vqs = kmalloc(sizeof(*vblk->vqs) * num_vqs, GFP_KERNEL);
+	vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
 	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);
+	names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
+	callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
+	vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
 	if (!names || !callbacks || !vqs) {
 		err = -ENOMEM;
 		goto out;

drivers/char/virtio_console.c

@@ -1539,19 +1539,29 @@ static void remove_port_data(struct port *port)
 	spin_lock_irq(&port->inbuf_lock);
 	/* Remove unused data this port might have received. */
 	discard_port_data(port);
+	spin_unlock_irq(&port->inbuf_lock);
 
 	/* Remove buffers we queued up for the Host to send us data in. */
-	while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
-		free_buf(buf, true);
+	do {
+		spin_lock_irq(&port->inbuf_lock);
+		buf = virtqueue_detach_unused_buf(port->in_vq);
 		spin_unlock_irq(&port->inbuf_lock);
+		if (buf)
+			free_buf(buf, true);
+	} while (buf);
 
 	spin_lock_irq(&port->outvq_lock);
 	reclaim_consumed_buffers(port);
+	spin_unlock_irq(&port->outvq_lock);
 
 	/* Free pending buffers from the out-queue. */
-	while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
-		free_buf(buf, true);
+	do {
+		spin_lock_irq(&port->outvq_lock);
+		buf = virtqueue_detach_unused_buf(port->out_vq);
 		spin_unlock_irq(&port->outvq_lock);
+		if (buf)
+			free_buf(buf, true);
+	} while (buf);
 }
 
 /*

drivers/virtio/config.c

@@ -1,12 +0,0 @@
-/* Configuration space parsing helpers for virtio.
- *
- * The configuration is [type][len][... len bytes ...] fields.
- *
- * Copyright 2007 Rusty Russell, IBM Corporation.
- * GPL v2 or later.
- */
-#include <linux/err.h>
-#include <linux/virtio.h>
-#include <linux/virtio_config.h>
-#include <linux/bug.h>
-

drivers/virtio/virtio_balloon.c

@@ -577,6 +577,8 @@ static int virtballoon_probe(struct virtio_device *vdev)
 
 	virtio_device_ready(vdev);
 
+	if (towards_target(vb))
+		virtballoon_changed(vdev);
 	return 0;
 
 out_del_vqs:

drivers/virtio/virtio_pci_legacy.c

@@ -212,10 +212,18 @@ int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 		return -ENODEV;
 	}
 
-	rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
-	if (rc)
-		rc = dma_set_mask_and_coherent(&pci_dev->dev,
-						DMA_BIT_MASK(32));
+	rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
+	if (rc) {
+		rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
+	} else {
+		/*
+		 * The virtio ring base address is expressed as a 32-bit PFN,
+		 * with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
+		 */
+		dma_set_coherent_mask(&pci_dev->dev,
+				DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
+	}
+
 	if (rc)
 		dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
 

drivers/virtio/virtio_ring.c

@@ -167,7 +167,7 @@ static bool vring_use_dma_api(struct virtio_device *vdev)
  * making all of the arch DMA ops work on the vring device itself
  * is a mess.  For now, we use the parent device for DMA ops.
  */
-static struct device *vring_dma_dev(const struct vring_virtqueue *vq)
+static inline struct device *vring_dma_dev(const struct vring_virtqueue *vq)
 {
 	return vq->vq.vdev->dev.parent;
 }
@@ -732,6 +732,7 @@ void virtqueue_disable_cb(struct virtqueue *_vq)
 
 	if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) {
 		vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
+		if (!vq->event)
 			vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
 	}
 
@@ -764,6 +765,7 @@ unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
 	 * entry. Always do both to keep code simple. */
 	if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
 		vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
+		if (!vq->event)
 			vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
 	}
 	vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, last_used_idx = vq->last_used_idx);
@@ -832,9 +834,10 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
 	 * more to do. */
 	/* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to
 	 * either clear the flags bit or point the event index at the next
-	 * entry. Always do both to keep code simple. */
+	 * entry. Always update the event index to keep code simple. */
 	if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
 		vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
+		if (!vq->event)
 			vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
 	}
 	/* TODO: tune this threshold */
@@ -953,6 +956,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
 	/* No callback?  Tell other side not to bother us. */
 	if (!callback) {
 		vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
+		if (!vq->event)
 			vq->vring.avail->flags = cpu_to_virtio16(vdev, vq->avail_flags_shadow);
 	}
 

tools/virtio/ringtest/Makefile

@@ -3,8 +3,8 @@ all:
 all: ring virtio_ring_0_9 virtio_ring_poll virtio_ring_inorder ptr_ring noring
 
 CFLAGS += -Wall
-CFLAGS += -pthread -O2 -ggdb
-LDFLAGS += -pthread -O2 -ggdb
+CFLAGS += -pthread -O2 -ggdb -flto -fwhole-program
+LDFLAGS += -pthread -O2 -ggdb -flto -fwhole-program
 
 main.o: main.c main.h
 ring.o: ring.c main.h

tools/virtio/ringtest/main.c

@@ -96,7 +96,13 @@ void set_affinity(const char *arg)
 	assert(!ret);
 }
 
-static void run_guest(void)
+void poll_used(void)
+{
+	while (used_empty())
+		busy_wait();
+}
+
+static void __attribute__((__flatten__)) run_guest(void)
 {
 	int completed_before;
 	int completed = 0;
@@ -141,7 +147,7 @@ static void run_guest(void)
 		assert(completed <= bufs);
 		assert(started <= bufs);
 		if (do_sleep) {
-			if (enable_call())
+			if (used_empty() && enable_call())
 				wait_for_call();
 		} else {
 			poll_used();
@@ -149,7 +155,13 @@ static void run_guest(void)
 	}
 }
 
-static void run_host(void)
+void poll_avail(void)
+{
+	while (avail_empty())
+		busy_wait();
+}
+
+static void __attribute__((__flatten__)) run_host(void)
 {
 	int completed_before;
 	int completed = 0;
@@ -160,7 +172,7 @@ static void run_host(void)
 
 	for (;;) {
 		if (do_sleep) {
-			if (enable_kick())
+			if (avail_empty() && enable_kick())
 				wait_for_kick();
 		} else {
 			poll_avail();

tools/virtio/ringtest/main.h

@@ -56,15 +56,15 @@ void alloc_ring(void);
 int add_inbuf(unsigned, void *, void *);
 void *get_buf(unsigned *, void **);
 void disable_call();
+bool used_empty();
 bool enable_call();
 void kick_available();
-void poll_used();
 /* host side */
 void disable_kick();
+bool avail_empty();
 bool enable_kick();
 bool use_buf(unsigned *, void **);
 void call_used();
-void poll_avail();
 
 /* implemented by main */
 extern bool do_sleep;

tools/virtio/ringtest/noring.c

@@ -24,8 +24,9 @@ void *get_buf(unsigned *lenp, void **bufp)
 	return "Buffer";
 }
 
-void poll_used(void)
+bool used_empty()
 {
+	return false;
 }
 
 void disable_call()
@@ -54,8 +55,9 @@ bool enable_kick()
 	assert(0);
 }
 
-void poll_avail(void)
+bool avail_empty()
 {
+	return false;
 }
 
 bool use_buf(unsigned *lenp, void **bufp)

tools/virtio/ringtest/ptr_ring.c

@@ -133,18 +133,9 @@ void *get_buf(unsigned *lenp, void **bufp)
 	return datap;
 }
 
-void poll_used(void)
+bool used_empty()
 {
-	void *b;
-
-	do {
-		if (tailcnt == headcnt || __ptr_ring_full(&array)) {
-			b = NULL;
-			barrier();
-		} else {
-			b = "Buffer\n";
-		}
-	} while (!b);
+	return (tailcnt == headcnt || __ptr_ring_full(&array));
 }
 
 void disable_call()
@@ -173,14 +164,9 @@ bool enable_kick()
 	assert(0);
 }
 
-void poll_avail(void)
+bool avail_empty()
 {
-	void *b;
-
-	do {
-		barrier();
-		b = __ptr_ring_peek(&array);
-	} while (!b);
+	return !__ptr_ring_peek(&array);
 }
 
 bool use_buf(unsigned *lenp, void **bufp)

tools/virtio/ringtest/ring.c

@@ -163,12 +163,11 @@ void *get_buf(unsigned *lenp, void **bufp)
 	return datap;
 }
 
-void poll_used(void)
+bool used_empty()
 {
 	unsigned head = (ring_size - 1) & guest.last_used_idx;
 
-	while (ring[head].flags & DESC_HW)
-		busy_wait();
+	return (ring[head].flags & DESC_HW);
 }
 
 void disable_call()
@@ -180,13 +179,11 @@ void disable_call()
 
 bool enable_call()
 {
-	unsigned head = (ring_size - 1) & guest.last_used_idx;
-
 	event->call_index = guest.last_used_idx;
 	/* Flush call index write */
 	/* Barrier D (for pairing) */
 	smp_mb();
-	return ring[head].flags & DESC_HW;
+	return used_empty();
 }
 
 void kick_available(void)
@@ -213,20 +210,17 @@ void disable_kick()
 
 bool enable_kick()
 {
-	unsigned head = (ring_size - 1) & host.used_idx;
-
 	event->kick_index = host.used_idx;
 	/* Barrier C (for pairing) */
 	smp_mb();
-	return !(ring[head].flags & DESC_HW);
+	return avail_empty();
 }
 
-void poll_avail(void)
+bool avail_empty()
 {
 	unsigned head = (ring_size - 1) & host.used_idx;
 
-	while (!(ring[head].flags & DESC_HW))
-		busy_wait();
+	return !(ring[head].flags & DESC_HW);
 }
 
 bool use_buf(unsigned *lenp, void **bufp)

tools/virtio/ringtest/virtio_ring_0_9.c

@@ -194,24 +194,16 @@ void *get_buf(unsigned *lenp, void **bufp)
 	return datap;
 }
 
-void poll_used(void)
+bool used_empty()
 {
+	unsigned short last_used_idx = guest.last_used_idx;
 #ifdef RING_POLL
-	unsigned head = (ring_size - 1) & guest.last_used_idx;
-
-	for (;;) {
+	unsigned short head = last_used_idx & (ring_size - 1);
 	unsigned index = ring.used->ring[head].id;
 
-		if ((index ^ guest.last_used_idx ^ 0x8000) & ~(ring_size - 1))
-			busy_wait();
-		else
-			break;
-	}
+	return (index ^ last_used_idx ^ 0x8000) & ~(ring_size - 1);
 #else
-	unsigned head = guest.last_used_idx;
-
-	while (ring.used->idx == head)
-		busy_wait();
+	return ring.used->idx == last_used_idx;
 #endif
 }
 
@@ -224,22 +216,11 @@ void disable_call()
 
 bool enable_call()
 {
-	unsigned short last_used_idx;
-
-	vring_used_event(&ring) = (last_used_idx = guest.last_used_idx);
+	vring_used_event(&ring) = guest.last_used_idx;
 	/* Flush call index write */
 	/* Barrier D (for pairing) */
 	smp_mb();
-#ifdef RING_POLL
-	{
-		unsigned short head = last_used_idx & (ring_size - 1);
-		unsigned index = ring.used->ring[head].id;
-
-		return (index ^ last_used_idx ^ 0x8000) & ~(ring_size - 1);
-	}
-#else
-	return ring.used->idx == last_used_idx;
-#endif
+	return used_empty();
 }
 
 void kick_available(void)
@@ -266,36 +247,21 @@ void disable_kick()
 
 bool enable_kick()
 {
-	unsigned head = host.used_idx;
-
-	vring_avail_event(&ring) = head;
+	vring_avail_event(&ring) = host.used_idx;
 	/* Barrier C (for pairing) */
 	smp_mb();
-#ifdef RING_POLL
-	{
-		unsigned index = ring.avail->ring[head & (ring_size - 1)];
-
-		return (index ^ head ^ 0x8000) & ~(ring_size - 1);
-	}
-#else
-	return head == ring.avail->idx;
-#endif
+	return avail_empty();
 }
 
-void poll_avail(void)
+bool avail_empty()
 {
 	unsigned head = host.used_idx;
 #ifdef RING_POLL
-	for (;;) {
 	unsigned index = ring.avail->ring[head & (ring_size - 1)];
-		if ((index ^ head ^ 0x8000) & ~(ring_size - 1))
-			busy_wait();
-		else
-			break;
-	}
+
+	return ((index ^ head ^ 0x8000) & ~(ring_size - 1));
 #else
-	while (ring.avail->idx == head)
-		busy_wait();
+	return head == ring.avail->idx;
 #endif
 }