From 0b90d0622ad290b3717a13489b396af52aea9d2d Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Mon, 14 Oct 2013 18:11:51 +1030
Subject: virtio_config: introduce size-based accessors.

This lets the us do endian conversion if necessary, and insulates the
drivers from that change.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 include/linux/virtio_config.h | 134 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)

(limited to 'include/linux')

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 29b9104232b4..490a4bbd59a3 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -162,5 +162,139 @@ int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
 	return 0;
 }
 
+/* Config space accessors. */
+#define virtio_cread(vdev, structname, member, ptr)			\
+	do {								\
+		/* Must match the member's type, and be integer */	\
+		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
+			(*ptr) = 1;					\
+									\
+		switch (sizeof(*ptr)) {					\
+		case 1:							\
+			*(ptr) = virtio_cread8(vdev,			\
+					       offsetof(structname, member)); \
+			break;						\
+		case 2:							\
+			*(ptr) = virtio_cread16(vdev,			\
+						offsetof(structname, member)); \
+			break;						\
+		case 4:							\
+			*(ptr) = virtio_cread32(vdev,			\
+						offsetof(structname, member)); \
+			break;						\
+		case 8:							\
+			*(ptr) = virtio_cread64(vdev,			\
+						offsetof(structname, member)); \
+			break;						\
+		default:						\
+			BUG();						\
+		}							\
+	} while(0)
+
+/* Config space accessors. */
+#define virtio_cwrite(vdev, structname, member, ptr)			\
+	do {								\
+		/* Must match the member's type, and be integer */	\
+		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
+			BUG_ON((*ptr) == 1);				\
+									\
+		switch (sizeof(*ptr)) {					\
+		case 1:							\
+			virtio_cwrite8(vdev,				\
+				       offsetof(structname, member),	\
+				       *(ptr));				\
+			break;						\
+		case 2:							\
+			virtio_cwrite16(vdev,				\
+					offsetof(structname, member),	\
+					*(ptr));			\
+			break;						\
+		case 4:							\
+			virtio_cwrite32(vdev,				\
+					offsetof(structname, member),	\
+					*(ptr));			\
+			break;						\
+		case 8:							\
+			virtio_cwrite64(vdev,				\
+					offsetof(structname, member),	\
+					*(ptr));			\
+			break;						\
+		default:						\
+			BUG();						\
+		}							\
+	} while(0)
+
+static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
+{
+	u8 ret;
+	vdev->config->get(vdev, offset, &ret, sizeof(ret));
+	return ret;
+}
+
+static inline void virtio_cread_bytes(struct virtio_device *vdev,
+				      unsigned int offset,
+				      void *buf, size_t len)
+{
+	vdev->config->get(vdev, offset, buf, len);
+}
+
+static inline void virtio_cwrite8(struct virtio_device *vdev,
+				  unsigned int offset, u8 val)
+{
+	vdev->config->set(vdev, offset, &val, sizeof(val));
+}
+
+static inline u16 virtio_cread16(struct virtio_device *vdev,
+				 unsigned int offset)
+{
+	u16 ret;
+	vdev->config->get(vdev, offset, &ret, sizeof(ret));
+	return ret;
+}
+
+static inline void virtio_cwrite16(struct virtio_device *vdev,
+				   unsigned int offset, u16 val)
+{
+	vdev->config->set(vdev, offset, &val, sizeof(val));
+}
+
+static inline u32 virtio_cread32(struct virtio_device *vdev,
+				 unsigned int offset)
+{
+	u32 ret;
+	vdev->config->get(vdev, offset, &ret, sizeof(ret));
+	return ret;
+}
+
+static inline void virtio_cwrite32(struct virtio_device *vdev,
+				   unsigned int offset, u32 val)
+{
+	vdev->config->set(vdev, offset, &val, sizeof(val));
+}
+
+static inline u64 virtio_cread64(struct virtio_device *vdev,
+				 unsigned int offset)
+{
+	u64 ret;
+	vdev->config->get(vdev, offset, &ret, sizeof(ret));
+	return ret;
+}
+
+static inline void virtio_cwrite64(struct virtio_device *vdev,
+				   unsigned int offset, u64 val)
+{
+	vdev->config->set(vdev, offset, &val, sizeof(val));
+}
+
+/* Conditional config space accessors. */
+#define virtio_cread_feature(vdev, fbit, structname, member, ptr)	\
+	({								\
+		int _r = 0;						\
+		if (!virtio_has_feature(vdev, fbit))			\
+			_r = -ENOENT;					\
+		else							\
+			virtio_cread((vdev), structname, member, ptr);	\
+		_r;							\
+	})
 
 #endif /* _LINUX_VIRTIO_CONFIG_H */
-- 
cgit v1.2.3-58-ga151


From 630b54d33493d1f67e79b148b5e361c5bbd3f29d Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Mon, 14 Oct 2013 18:11:51 +1030
Subject: virtio_config: remove virtio_config_val

The virtio_cread() functions should now be used.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 include/linux/virtio_config.h | 27 ---------------------------
 1 file changed, 27 deletions(-)

(limited to 'include/linux')

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 490a4bbd59a3..e8f8f71e843c 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -96,33 +96,6 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev,
 	return test_bit(fbit, vdev->features);
 }
 
-/**
- * virtio_config_val - look for a feature and get a virtio config entry.
- * @vdev: the virtio device
- * @fbit: the feature bit
- * @offset: the type to search for.
- * @v: a pointer to the value to fill in.
- *
- * The return value is -ENOENT if the feature doesn't exist.  Otherwise
- * the config value is copied into whatever is pointed to by v. */
-#define virtio_config_val(vdev, fbit, offset, v) \
-	virtio_config_buf((vdev), (fbit), (offset), (v), sizeof(*v))
-
-#define virtio_config_val_len(vdev, fbit, offset, v, len) \
-	virtio_config_buf((vdev), (fbit), (offset), (v), (len))
-
-static inline int virtio_config_buf(struct virtio_device *vdev,
-				    unsigned int fbit,
-				    unsigned int offset,
-				    void *buf, unsigned len)
-{
-	if (!virtio_has_feature(vdev, fbit))
-		return -ENOENT;
-
-	vdev->config->get(vdev, offset, buf, len);
-	return 0;
-}
-
 static inline
 struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
 					vq_callback_t *c, const char *n)
-- 
cgit v1.2.3-58-ga151


From 46f9c2b925ac12e5ad8b8b7c90c71dacc9d5db37 Mon Sep 17 00:00:00 2001
From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Date: Tue, 29 Oct 2013 09:38:50 +1030
Subject: virtio_ring: change host notification API

Currently a host kick error is silently ignored and not reflected in
the virtqueue of a particular virtio device.

Changing the notify API for guest->host notification seems to be one
prerequisite in order to be able to handle such errors in the context
where the kick is triggered.

This patch changes the notify API. The notify function must return a
bool return value. It returns false if the host notification failed.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/lguest/lguest_device.c         |  3 ++-
 drivers/remoteproc/remoteproc_virtio.c |  3 ++-
 drivers/s390/kvm/kvm_virtio.c          |  8 ++++++--
 drivers/s390/kvm/virtio_ccw.c          |  5 ++++-
 drivers/virtio/virtio_mmio.c           |  3 ++-
 drivers/virtio/virtio_pci.c            |  3 ++-
 drivers/virtio/virtio_ring.c           |  4 ++--
 include/linux/virtio_ring.h            |  2 +-
 tools/virtio/virtio_test.c             |  3 ++-
 tools/virtio/vringh_test.c             | 13 +++++++++----
 10 files changed, 32 insertions(+), 15 deletions(-)

(limited to 'include/linux')

diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index b3256ff0d426..d0a1d8a45c81 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -229,7 +229,7 @@ struct lguest_vq_info {
  * make a hypercall.  We hand the physical address of the virtqueue so the Host
  * knows which virtqueue we're talking about.
  */
-static void lg_notify(struct virtqueue *vq)
+static bool lg_notify(struct virtqueue *vq)
 {
 	/*
 	 * We store our virtqueue information in the "priv" pointer of the
@@ -238,6 +238,7 @@ static void lg_notify(struct virtqueue *vq)
 	struct lguest_vq_info *lvq = vq->priv;
 
 	hcall(LHCALL_NOTIFY, lvq->config.pfn << PAGE_SHIFT, 0, 0, 0);
+	return true;
 }
 
 /* An extern declaration inside a C file is bad form.  Don't do it. */
diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index b09c75c21b60..a34b50690b4e 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -30,7 +30,7 @@
 #include "remoteproc_internal.h"
 
 /* kick the remote processor, and let it know which virtqueue to poke at */
-static void rproc_virtio_notify(struct virtqueue *vq)
+static bool rproc_virtio_notify(struct virtqueue *vq)
 {
 	struct rproc_vring *rvring = vq->priv;
 	struct rproc *rproc = rvring->rvdev->rproc;
@@ -39,6 +39,7 @@ static void rproc_virtio_notify(struct virtqueue *vq)
 	dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);
 
 	rproc->ops->kick(rproc, notifyid);
+	return true;
 }
 
 /**
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index af2166fa5159..1abd0db29915 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -166,11 +166,15 @@ static void kvm_reset(struct virtio_device *vdev)
  * make a hypercall.  We hand the address  of the virtqueue so the Host
  * knows which virtqueue we're talking about.
  */
-static void kvm_notify(struct virtqueue *vq)
+static bool kvm_notify(struct virtqueue *vq)
 {
+	long rc;
 	struct kvm_vqconfig *config = vq->priv;
 
-	kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, config->address);
+	rc = kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, config->address);
+	if (rc < 0)
+		return false;
+	return true;
 }
 
 /*
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 779dc5136291..d6297176ab85 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -162,7 +162,7 @@ static inline long do_kvm_notify(struct subchannel_id schid,
 	return __rc;
 }
 
-static void virtio_ccw_kvm_notify(struct virtqueue *vq)
+static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
 {
 	struct virtio_ccw_vq_info *info = vq->priv;
 	struct virtio_ccw_device *vcdev;
@@ -171,6 +171,9 @@ static void virtio_ccw_kvm_notify(struct virtqueue *vq)
 	vcdev = to_vc_device(info->vq->vdev);
 	ccw_device_get_schid(vcdev->cdev, &schid);
 	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
+	if (info->cookie < 0)
+		return false;
+	return true;
 }
 
 static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 1ba0d6831015..e9fdeb861992 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -219,13 +219,14 @@ static void vm_reset(struct virtio_device *vdev)
 /* Transport interface */
 
 /* the notify function used when creating a virt queue */
-static void vm_notify(struct virtqueue *vq)
+static bool vm_notify(struct virtqueue *vq)
 {
 	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
 
 	/* We write the queue's selector into the notification register to
 	 * signal the other end */
 	writel(vq->index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
+	return true;
 }
 
 /* Notify all virtqueues on an interrupt. */
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 98917fc872a4..a37c69941d30 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -197,13 +197,14 @@ static void vp_reset(struct virtio_device *vdev)
 }
 
 /* the notify function used when creating a virt queue */
-static void vp_notify(struct virtqueue *vq)
+static bool vp_notify(struct virtqueue *vq)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 
 	/* we write the queue's selector into the notification register to
 	 * signal the other end */
 	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
+	return true;
 }
 
 /* Handle a configuration change: Tell driver if it wants to know. */
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 6547d46171b3..97dd51619b55 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -81,7 +81,7 @@ struct vring_virtqueue
 	u16 last_used_idx;
 
 	/* How to notify other side. FIXME: commonalize hcalls! */
-	void (*notify)(struct virtqueue *vq);
+	bool (*notify)(struct virtqueue *vq);
 
 #ifdef DEBUG
 	/* They're supposed to lock for us. */
@@ -744,7 +744,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
 				      struct virtio_device *vdev,
 				      bool weak_barriers,
 				      void *pages,
-				      void (*notify)(struct virtqueue *),
+				      bool (*notify)(struct virtqueue *),
 				      void (*callback)(struct virtqueue *),
 				      const char *name)
 {
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index b300787af8e0..67e06fe18c03 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -71,7 +71,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
 				      struct virtio_device *vdev,
 				      bool weak_barriers,
 				      void *pages,
-				      void (*notify)(struct virtqueue *vq),
+				      bool (*notify)(struct virtqueue *vq),
 				      void (*callback)(struct virtqueue *vq),
 				      const char *name);
 void vring_del_virtqueue(struct virtqueue *vq);
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
index da7a19558281..059cb723f6a7 100644
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -41,13 +41,14 @@ struct vdev_info {
 	struct vhost_memory *mem;
 };
 
-void vq_notify(struct virtqueue *vq)
+bool vq_notify(struct virtqueue *vq)
 {
 	struct vq_info *info = vq->priv;
 	unsigned long long v = 1;
 	int r;
 	r = write(info->kick, &v, sizeof v);
 	assert(r == sizeof v);
+	return true;
 }
 
 void vq_callback(struct virtqueue *vq)
diff --git a/tools/virtio/vringh_test.c b/tools/virtio/vringh_test.c
index d053ea40c001..14a4f4cab5b9 100644
--- a/tools/virtio/vringh_test.c
+++ b/tools/virtio/vringh_test.c
@@ -22,7 +22,7 @@ static u64 user_addr_offset;
 #define RINGSIZE 256
 #define ALIGN 4096
 
-static void never_notify_host(struct virtqueue *vq)
+static bool never_notify_host(struct virtqueue *vq)
 {
 	abort();
 }
@@ -65,17 +65,22 @@ struct guest_virtio_device {
 	unsigned long notifies;
 };
 
-static void parallel_notify_host(struct virtqueue *vq)
+static bool parallel_notify_host(struct virtqueue *vq)
 {
+	int rc;
 	struct guest_virtio_device *gvdev;
 
 	gvdev = container_of(vq->vdev, struct guest_virtio_device, vdev);
-	write(gvdev->to_host_fd, "", 1);
+	rc = write(gvdev->to_host_fd, "", 1);
+	if (rc < 0)
+		return false;
 	gvdev->notifies++;
+	return true;
 }
 
-static void no_notify_host(struct virtqueue *vq)
+static bool no_notify_host(struct virtqueue *vq)
 {
+	return true;
 }
 
 #define NUM_XFERS (10000000)
-- 
cgit v1.2.3-58-ga151


From 5b1bf7cb673ade0ab5c75f200dce911d9fb91c21 Mon Sep 17 00:00:00 2001
From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Date: Tue, 29 Oct 2013 09:39:48 +1030
Subject: virtio_ring: let virtqueue_{kick()/notify()} return a bool

virtqueue_{kick()/notify()} should exploit the new host notification API.
If the notify call returned with a negative value the host kick failed
(e.g. a kick triggered after a device was hot-unplugged). In this case
the virtqueue is set to 'broken' and false is returned, otherwise true.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/virtio/virtio_ring.c | 20 ++++++++++++++++----
 include/linux/virtio.h       |  4 ++--
 2 files changed, 18 insertions(+), 6 deletions(-)

(limited to 'include/linux')

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 97dd51619b55..b47142723119 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -430,13 +430,22 @@ EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
  * @vq: the struct virtqueue
  *
  * This does not need to be serialized.
+ *
+ * Returns false if host notify failed or queue is broken, otherwise true.
  */
-void virtqueue_notify(struct virtqueue *_vq)
+bool virtqueue_notify(struct virtqueue *_vq)
 {
 	struct vring_virtqueue *vq = to_vvq(_vq);
 
+	if (unlikely(vq->broken))
+		return false;
+
 	/* Prod other side to tell it about changes. */
-	vq->notify(_vq);
+	if (vq->notify(_vq) < 0) {
+		vq->broken = true;
+		return false;
+	}
+	return true;
 }
 EXPORT_SYMBOL_GPL(virtqueue_notify);
 
@@ -449,11 +458,14 @@ EXPORT_SYMBOL_GPL(virtqueue_notify);
  *
  * Caller must ensure we don't call this with other virtqueue
  * operations at the same time (except where noted).
+ *
+ * Returns false if kick failed, otherwise true.
  */
-void virtqueue_kick(struct virtqueue *vq)
+bool virtqueue_kick(struct virtqueue *vq)
 {
 	if (virtqueue_kick_prepare(vq))
-		virtqueue_notify(vq);
+		return virtqueue_notify(vq);
+	return true;
 }
 EXPORT_SYMBOL_GPL(virtqueue_kick);
 
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 36d36cc89329..9b4de15fcb2f 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -51,11 +51,11 @@ int virtqueue_add_sgs(struct virtqueue *vq,
 		      void *data,
 		      gfp_t gfp);
 
-void virtqueue_kick(struct virtqueue *vq);
+bool virtqueue_kick(struct virtqueue *vq);
 
 bool virtqueue_kick_prepare(struct virtqueue *vq);
 
-void virtqueue_notify(struct virtqueue *vq);
+bool virtqueue_notify(struct virtqueue *vq);
 
 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
 
-- 
cgit v1.2.3-58-ga151


From b3b32c94133621c9ba7e4c8f29ec7533f2f4d8ec Mon Sep 17 00:00:00 2001
From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Date: Tue, 29 Oct 2013 09:40:19 +1030
Subject: virtio_ring: add new function virtqueue_is_broken()

Add new function virtqueue_is_broken(). Callers of virtqueue_get_buf()
should check for a broken queue.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/virtio/virtio_ring.c | 8 ++++++++
 include/linux/virtio.h       | 2 ++
 2 files changed, 10 insertions(+)

(limited to 'include/linux')

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index b47142723119..f47777582ce5 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -851,4 +851,12 @@ unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)
 }
 EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
 
+bool virtqueue_is_broken(struct virtqueue *_vq)
+{
+	struct vring_virtqueue *vq = to_vvq(_vq);
+
+	return vq->broken;
+}
+EXPORT_SYMBOL_GPL(virtqueue_is_broken);
+
 MODULE_LICENSE("GPL");
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 9b4de15fcb2f..e4abb84199be 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -73,6 +73,8 @@ void *virtqueue_detach_unused_buf(struct virtqueue *vq);
 
 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
 
+bool virtqueue_is_broken(struct virtqueue *vq);
+
 /**
  * virtio_device - representation of a device using virtio
  * @index: unique position on the virtio bus
-- 
cgit v1.2.3-58-ga151