Merge remote-tracking branch 'stefanha/block' into staging

* stefanha/block:
  sheepdog: pass oid directly to send_pending_req()
  sheepdog: don't update inode when create_and_write fails
  block/raw-win32: Fix compiler warnings (wrong format specifiers)
  qemu-img: report size overflow error message
  cutils: change strtosz_suffix_unit function
  virtio-blk: Return UNSUPP for unknown request types
  virtio-blk: add x-data-plane=on|off performance feature
  dataplane: add virtio-blk data plane code
  virtio-blk: restore VirtIOBlkConf->config_wce flag
  iov: add qemu_iovec_concat_iov()
  test-iov: add iov_discard_front/back() testcases
  iov: add iov_discard_front/back() to remove data
  dataplane: add Linux AIO request queue
  dataplane: add event loop
  dataplane: add virtqueue vring code
  dataplane: add host memory mapping code
  configure: add CONFIG_VIRTIO_BLK_DATA_PLANE
  raw-posix: add raw_get_aio_fd() for virtio-blk-data-plane

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/hw/dataplane/ioq.h b/hw/dataplane/ioq.h
new file mode 100644
index 0000000000..b49b5de7f4
--- /dev/null
+++ b/hw/dataplane/ioq.h
@@ -0,0 +1,57 @@
+/*
+ * Linux AIO request queue
+ *
+ * Copyright 2012 IBM, Corp.
+ * Copyright 2012 Red Hat, Inc. and/or its affiliates
+ *
+ * Authors:
+ *   Stefan Hajnoczi <stefanha@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef IOQ_H
+#define IOQ_H
+
+#include <libaio.h>
+#include "qemu/event_notifier.h"
+
+typedef struct {
+    int fd;                         /* file descriptor */
+    unsigned int max_reqs;          /* max length of freelist and queue */
+
+    io_context_t io_ctx;            /* Linux AIO context */
+    EventNotifier io_notifier;      /* Linux AIO eventfd */
+
+    /* Requests can complete in any order so a free list is necessary to manage
+     * available iocbs.
+     */
+    struct iocb **freelist;         /* free iocbs */
+    unsigned int freelist_idx;
+
+    /* Multiple requests are queued up before submitting them all in one go */
+    struct iocb **queue;            /* queued iocbs */
+    unsigned int queue_idx;
+} IOQueue;
+
+void ioq_init(IOQueue *ioq, int fd, unsigned int max_reqs);
+void ioq_cleanup(IOQueue *ioq);
+EventNotifier *ioq_get_notifier(IOQueue *ioq);
+struct iocb *ioq_get_iocb(IOQueue *ioq);
+void ioq_put_iocb(IOQueue *ioq, struct iocb *iocb);
+struct iocb *ioq_rdwr(IOQueue *ioq, bool read, struct iovec *iov,
+                      unsigned int count, long long offset);
+int ioq_submit(IOQueue *ioq);
+
+static inline unsigned int ioq_num_queued(IOQueue *ioq)
+{
+    return ioq->queue_idx;
+}
+
+typedef void IOQueueCompletion(struct iocb *iocb, ssize_t ret, void *opaque);
+int ioq_run_completion(IOQueue *ioq, IOQueueCompletion *completion,
+                       void *opaque);
+
+#endif /* IOQ_H */