Merge branch 'work.vmci' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vmci iov_iter updates from Al Viro:
 "Get rid of "is it an iovec or an entire array?" flags in vmxi - just
  use iov_iter. Simplifies the living hell out of that code..."

* 'work.vmci' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vmci: the same on the send side...
  vmci: simplify qp_dequeue_locked()
  vmci: get rid of qp_memcpy_from_queue()
  vmci: fix buf_size in case of iovec-based accesses

drivers/misc/vmw_vmci/vmci_queue_pair.c

@@ -129,23 +129,6 @@
  * *_MEM state, and vice versa.
  */
 
-/*
- * VMCIMemcpy{To,From}QueueFunc() prototypes.  Functions of these
- * types are passed around to enqueue and dequeue routines.  Note that
- * often the functions passed are simply wrappers around memcpy
- * itself.
- *
- * Note: In order for the memcpy typedefs to be compatible with the VMKernel,
- * there's an unused last parameter for the hosted side.  In
- * ESX, that parameter holds a buffer type.
- */
-typedef int vmci_memcpy_to_queue_func(struct vmci_queue *queue,
-				      u64 queue_offset, const void *src,
-				      size_t src_offset, size_t size);
-typedef int vmci_memcpy_from_queue_func(void *dest, size_t dest_offset,
-					const struct vmci_queue *queue,
-					u64 queue_offset, size_t size);
-
 /* The Kernel specific component of the struct vmci_queue structure. */
 struct vmci_queue_kern_if {
 	struct mutex __mutex;	/* Protects the queue. */
@@ -351,11 +334,10 @@ static void *qp_alloc_queue(u64 size, u32 flags)
  * by traversing the offset -> page translation structure for the queue.
  * Assumes that offset + size does not wrap around in the queue.
  */
-static int __qp_memcpy_to_queue(struct vmci_queue *queue,
-				u64 queue_offset,
-				const void *src,
-				size_t size,
-				bool is_iovec)
+static int qp_memcpy_to_queue_iter(struct vmci_queue *queue,
+				  u64 queue_offset,
+				  struct iov_iter *from,
+				  size_t size)
 {
 	struct vmci_queue_kern_if *kernel_if = queue->kernel_if;
 	size_t bytes_copied = 0;
@@ -380,23 +362,12 @@ static int __qp_memcpy_to_queue(struct vmci_queue *queue,
 		else
 			to_copy = size - bytes_copied;
 
-		if (is_iovec) {
-			struct msghdr *msg = (struct msghdr *)src;
-			int err;
-
-			/* The iovec will track bytes_copied internally. */
-			err = memcpy_from_msg((u8 *)va + page_offset,
-					      msg, to_copy);
-			if (err != 0) {
-				if (kernel_if->host)
-					kunmap(kernel_if->u.h.page[page_index]);
-				return VMCI_ERROR_INVALID_ARGS;
-			}
-		} else {
-			memcpy((u8 *)va + page_offset,
-			       (u8 *)src + bytes_copied, to_copy);
+		if (!copy_from_iter_full((u8 *)va + page_offset, to_copy,
+					 from)) {
+			if (kernel_if->host)
+				kunmap(kernel_if->u.h.page[page_index]);
+			return VMCI_ERROR_INVALID_ARGS;
 		}
-
 		bytes_copied += to_copy;
 		if (kernel_if->host)
 			kunmap(kernel_if->u.h.page[page_index]);
@@ -411,11 +382,9 @@ static int __qp_memcpy_to_queue(struct vmci_queue *queue,
  * by traversing the offset -> page translation structure for the queue.
  * Assumes that offset + size does not wrap around in the queue.
  */
-static int __qp_memcpy_from_queue(void *dest,
-				  const struct vmci_queue *queue,
-				  u64 queue_offset,
-				  size_t size,
-				  bool is_iovec)
+static int qp_memcpy_from_queue_iter(struct iov_iter *to,
+				    const struct vmci_queue *queue,
+				    u64 queue_offset, size_t size)
 {
 	struct vmci_queue_kern_if *kernel_if = queue->kernel_if;
 	size_t bytes_copied = 0;
@@ -427,6 +396,7 @@ static int __qp_memcpy_from_queue(void *dest,
 		    (queue_offset + bytes_copied) & (PAGE_SIZE - 1);
 		void *va;
 		size_t to_copy;
+		int err;
 
 		if (kernel_if->host)
 			va = kmap(kernel_if->u.h.page[page_index]);
@@ -440,23 +410,12 @@ static int __qp_memcpy_from_queue(void *dest,
 		else
 			to_copy = size - bytes_copied;
 
-		if (is_iovec) {
-			struct msghdr *msg = dest;
-			int err;
-
-			/* The iovec will track bytes_copied internally. */
-			err = memcpy_to_msg(msg, (u8 *)va + page_offset,
-					     to_copy);
-			if (err != 0) {
-				if (kernel_if->host)
-					kunmap(kernel_if->u.h.page[page_index]);
-				return VMCI_ERROR_INVALID_ARGS;
-			}
-		} else {
-			memcpy((u8 *)dest + bytes_copied,
-			       (u8 *)va + page_offset, to_copy);
+		err = copy_to_iter((u8 *)va + page_offset, to_copy, to);
+		if (err != to_copy) {
+			if (kernel_if->host)
+				kunmap(kernel_if->u.h.page[page_index]);
+			return VMCI_ERROR_INVALID_ARGS;
 		}
-
 		bytes_copied += to_copy;
 		if (kernel_if->host)
 			kunmap(kernel_if->u.h.page[page_index]);
@@ -569,54 +528,6 @@ static int qp_populate_ppn_set(u8 *call_buf, const struct ppn_set *ppn_set)
 	return VMCI_SUCCESS;
 }
 
-static int qp_memcpy_to_queue(struct vmci_queue *queue,
-			      u64 queue_offset,
-			      const void *src, size_t src_offset, size_t size)
-{
-	return __qp_memcpy_to_queue(queue, queue_offset,
-				    (u8 *)src + src_offset, size, false);
-}
-
-static int qp_memcpy_from_queue(void *dest,
-				size_t dest_offset,
-				const struct vmci_queue *queue,
-				u64 queue_offset, size_t size)
-{
-	return __qp_memcpy_from_queue((u8 *)dest + dest_offset,
-				      queue, queue_offset, size, false);
-}
-
-/*
- * Copies from a given iovec from a VMCI Queue.
- */
-static int qp_memcpy_to_queue_iov(struct vmci_queue *queue,
-				  u64 queue_offset,
-				  const void *msg,
-				  size_t src_offset, size_t size)
-{
-
-	/*
-	 * We ignore src_offset because src is really a struct iovec * and will
-	 * maintain offset internally.
-	 */
-	return __qp_memcpy_to_queue(queue, queue_offset, msg, size, true);
-}
-
-/*
- * Copies to a given iovec from a VMCI Queue.
- */
-static int qp_memcpy_from_queue_iov(void *dest,
-				    size_t dest_offset,
-				    const struct vmci_queue *queue,
-				    u64 queue_offset, size_t size)
-{
-	/*
-	 * We ignore dest_offset because dest is really a struct iovec * and
-	 * will maintain offset internally.
-	 */
-	return __qp_memcpy_from_queue(dest, queue, queue_offset, size, true);
-}
-
 /*
  * Allocates kernel VA space of specified size plus space for the queue
  * and kernel interface.  This is different from the guest queue allocator,
@@ -2629,12 +2540,11 @@ static bool qp_wait_for_ready_queue(struct vmci_qp *qpair)
 static ssize_t qp_enqueue_locked(struct vmci_queue *produce_q,
 				 struct vmci_queue *consume_q,
 				 const u64 produce_q_size,
-				 const void *buf,
-				 size_t buf_size,
-				 vmci_memcpy_to_queue_func memcpy_to_queue)
+				 struct iov_iter *from)
 {
 	s64 free_space;
 	u64 tail;
+	size_t buf_size = iov_iter_count(from);
 	size_t written;
 	ssize_t result;
 
@@ -2654,15 +2564,15 @@ static ssize_t qp_enqueue_locked(struct vmci_queue *produce_q,
 	written = (size_t) (free_space > buf_size ? buf_size : free_space);
 	tail = vmci_q_header_producer_tail(produce_q->q_header);
 	if (likely(tail + written < produce_q_size)) {
-		result = memcpy_to_queue(produce_q, tail, buf, 0, written);
+		result = qp_memcpy_to_queue_iter(produce_q, tail, from, written);
 	} else {
 		/* Tail pointer wraps around. */
 
 		const size_t tmp = (size_t) (produce_q_size - tail);
 
-		result = memcpy_to_queue(produce_q, tail, buf, 0, tmp);
+		result = qp_memcpy_to_queue_iter(produce_q, tail, from, tmp);
 		if (result >= VMCI_SUCCESS)
-			result = memcpy_to_queue(produce_q, 0, buf, tmp,
+			result = qp_memcpy_to_queue_iter(produce_q, 0, from,
 						 written - tmp);
 	}
 
@@ -2690,11 +2600,10 @@ static ssize_t qp_enqueue_locked(struct vmci_queue *produce_q,
 static ssize_t qp_dequeue_locked(struct vmci_queue *produce_q,
 				 struct vmci_queue *consume_q,
 				 const u64 consume_q_size,
-				 void *buf,
-				 size_t buf_size,
-				 vmci_memcpy_from_queue_func memcpy_from_queue,
+				 struct iov_iter *to,
 				 bool update_consumer)
 {
+	size_t buf_size = iov_iter_count(to);
 	s64 buf_ready;
 	u64 head;
 	size_t read;
@@ -2716,15 +2625,15 @@ static ssize_t qp_dequeue_locked(struct vmci_queue *produce_q,
 	read = (size_t) (buf_ready > buf_size ? buf_size : buf_ready);
 	head = vmci_q_header_consumer_head(produce_q->q_header);
 	if (likely(head + read < consume_q_size)) {
-		result = memcpy_from_queue(buf, 0, consume_q, head, read);
+		result = qp_memcpy_from_queue_iter(to, consume_q, head, read);
 	} else {
 		/* Head pointer wraps around. */
 
 		const size_t tmp = (size_t) (consume_q_size - head);
 
-		result = memcpy_from_queue(buf, 0, consume_q, head, tmp);
+		result = qp_memcpy_from_queue_iter(to, consume_q, head, tmp);
 		if (result >= VMCI_SUCCESS)
-			result = memcpy_from_queue(buf, tmp, consume_q, 0,
+			result = qp_memcpy_from_queue_iter(to, consume_q, 0,
 						   read - tmp);
 
 	}
@@ -3118,18 +3027,21 @@ ssize_t vmci_qpair_enqueue(struct vmci_qp *qpair,
 			   int buf_type)
 {
 	ssize_t result;
+	struct iov_iter from;
+	struct kvec v = {.iov_base = (void *)buf, .iov_len = buf_size};
 
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
+	iov_iter_kvec(&from, WRITE | ITER_KVEC, &v, 1, buf_size);
+
 	qp_lock(qpair);
 
 	do {
 		result = qp_enqueue_locked(qpair->produce_q,
 					   qpair->consume_q,
 					   qpair->produce_q_size,
-					   buf, buf_size,
-					   qp_memcpy_to_queue);
+					   &from);
 
 		if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
 		    !qp_wait_for_ready_queue(qpair))
@@ -3159,18 +3071,21 @@ ssize_t vmci_qpair_dequeue(struct vmci_qp *qpair,
 			   int buf_type)
 {
 	ssize_t result;
+	struct iov_iter to;
+	struct kvec v = {.iov_base = buf, .iov_len = buf_size};
 
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
+	iov_iter_kvec(&to, READ | ITER_KVEC, &v, 1, buf_size);
+
 	qp_lock(qpair);
 
 	do {
 		result = qp_dequeue_locked(qpair->produce_q,
 					   qpair->consume_q,
 					   qpair->consume_q_size,
-					   buf, buf_size,
-					   qp_memcpy_from_queue, true);
+					   &to, true);
 
 		if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
 		    !qp_wait_for_ready_queue(qpair))
@@ -3200,19 +3115,22 @@ ssize_t vmci_qpair_peek(struct vmci_qp *qpair,
 			size_t buf_size,
 			int buf_type)
 {
+	struct iov_iter to;
+	struct kvec v = {.iov_base = buf, .iov_len = buf_size};
 	ssize_t result;
 
 	if (!qpair || !buf)
 		return VMCI_ERROR_INVALID_ARGS;
 
+	iov_iter_kvec(&to, READ | ITER_KVEC, &v, 1, buf_size);
+
 	qp_lock(qpair);
 
 	do {
 		result = qp_dequeue_locked(qpair->produce_q,
 					   qpair->consume_q,
 					   qpair->consume_q_size,
-					   buf, buf_size,
-					   qp_memcpy_from_queue, false);
+					   &to, false);
 
 		if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
 		    !qp_wait_for_ready_queue(qpair))
@@ -3253,8 +3171,7 @@ ssize_t vmci_qpair_enquev(struct vmci_qp *qpair,
 		result = qp_enqueue_locked(qpair->produce_q,
 					   qpair->consume_q,
 					   qpair->produce_q_size,
-					   msg, iov_size,
-					   qp_memcpy_to_queue_iov);
+					   &msg->msg_iter);
 
 		if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
 		    !qp_wait_for_ready_queue(qpair))
@@ -3295,9 +3212,7 @@ ssize_t vmci_qpair_dequev(struct vmci_qp *qpair,
 		result = qp_dequeue_locked(qpair->produce_q,
 					   qpair->consume_q,
 					   qpair->consume_q_size,
-					   msg, iov_size,
-					   qp_memcpy_from_queue_iov,
-					   true);
+					   &msg->msg_iter, true);
 
 		if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
 		    !qp_wait_for_ready_queue(qpair))
@@ -3339,9 +3254,7 @@ ssize_t vmci_qpair_peekv(struct vmci_qp *qpair,
 		result = qp_dequeue_locked(qpair->produce_q,
 					   qpair->consume_q,
 					   qpair->consume_q_size,
-					   msg, iov_size,
-					   qp_memcpy_from_queue_iov,
-					   false);
+					   &msg->msg_iter, false);
 
 		if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
 		    !qp_wait_for_ready_queue(qpair))