Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 270 insertions, 0 deletions

diff --git a/qemu/block/stream.c b/qemu/block/stream.c
new file mode 100644
index 000000000..ab0bd057f
--- /dev/null
+++ b/qemu/block/stream.c
@@ -0,0 +1,270 @@
+/*
+ * Image streaming
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "trace.h"
+#include "block/block_int.h"
+#include "block/blockjob.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/ratelimit.h"
+
+enum {
+    /*
+     * Size of data buffer for populating the image file.  This should be large
+     * enough to process multiple clusters in a single call, so that populating
+     * contiguous regions of the image is efficient.
+     */
+    STREAM_BUFFER_SIZE = 512 * 1024, /* in bytes */
+};
+
+#define SLICE_TIME 100000000ULL /* ns */
+
+typedef struct StreamBlockJob {
+    BlockJob common;
+    RateLimit limit;
+    BlockDriverState *base;
+    BlockdevOnError on_error;
+    char *backing_file_str;
+} StreamBlockJob;
+
+static int coroutine_fn stream_populate(BlockDriverState *bs,
+                                        int64_t sector_num, int nb_sectors,
+                                        void *buf)
+{
+    struct iovec iov = {
+        .iov_base = buf,
+        .iov_len  = nb_sectors * BDRV_SECTOR_SIZE,
+    };
+    QEMUIOVector qiov;
+
+    qemu_iovec_init_external(&qiov, &iov, 1);
+
+    /* Copy-on-read the unallocated clusters */
+    return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov);
+}
+
+static void close_unused_images(BlockDriverState *top, BlockDriverState *base,
+                                const char *base_id)
+{
+    BlockDriverState *intermediate;
+    intermediate = top->backing_hd;
+
+    /* Must assign before bdrv_delete() to prevent traversing dangling pointer
+     * while we delete backing image instances.
+     */
+    bdrv_set_backing_hd(top, base);
+
+    while (intermediate) {
+        BlockDriverState *unused;
+
+        /* reached base */
+        if (intermediate == base) {
+            break;
+        }
+
+        unused = intermediate;
+        intermediate = intermediate->backing_hd;
+        bdrv_set_backing_hd(unused, NULL);
+        bdrv_unref(unused);
+    }
+
+    bdrv_refresh_limits(top, NULL);
+}
+
+typedef struct {
+    int ret;
+    bool reached_end;
+} StreamCompleteData;
+
+static void stream_complete(BlockJob *job, void *opaque)
+{
+    StreamBlockJob *s = container_of(job, StreamBlockJob, common);
+    StreamCompleteData *data = opaque;
+    BlockDriverState *base = s->base;
+
+    if (!block_job_is_cancelled(&s->common) && data->reached_end &&
+        data->ret == 0) {
+        const char *base_id = NULL, *base_fmt = NULL;
+        if (base) {
+            base_id = s->backing_file_str;
+            if (base->drv) {
+                base_fmt = base->drv->format_name;
+            }
+        }
+        data->ret = bdrv_change_backing_file(job->bs, base_id, base_fmt);
+        close_unused_images(job->bs, base, base_id);
+    }
+
+    g_free(s->backing_file_str);
+    block_job_completed(&s->common, data->ret);
+    g_free(data);
+}
+
+static void coroutine_fn stream_run(void *opaque)
+{
+    StreamBlockJob *s = opaque;
+    StreamCompleteData *data;
+    BlockDriverState *bs = s->common.bs;
+    BlockDriverState *base = s->base;
+    int64_t sector_num, end;
+    int error = 0;
+    int ret = 0;
+    int n = 0;
+    void *buf;
+
+    if (!bs->backing_hd) {
+        block_job_completed(&s->common, 0);
+        return;
+    }
+
+    s->common.len = bdrv_getlength(bs);
+    if (s->common.len < 0) {
+        block_job_completed(&s->common, s->common.len);
+        return;
+    }
+
+    end = s->common.len >> BDRV_SECTOR_BITS;
+    buf = qemu_blockalign(bs, STREAM_BUFFER_SIZE);
+
+    /* Turn on copy-on-read for the whole block device so that guest read
+     * requests help us make progress.  Only do this when copying the entire
+     * backing chain since the copy-on-read operation does not take base into
+     * account.
+     */
+    if (!base) {
+        bdrv_enable_copy_on_read(bs);
+    }
+
+    for (sector_num = 0; sector_num < end; sector_num += n) {
+        uint64_t delay_ns = 0;
+        bool copy;
+
+wait:
+        /* Note that even when no rate limit is applied we need to yield
+         * with no pending I/O here so that bdrv_drain_all() returns.
+         */
+        block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns);
+        if (block_job_is_cancelled(&s->common)) {
+            break;
+        }
+
+        copy = false;
+
+        ret = bdrv_is_allocated(bs, sector_num,
+                                STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n);
+        if (ret == 1) {
+            /* Allocated in the top, no need to copy.  */
+        } else if (ret >= 0) {
+            /* Copy if allocated in the intermediate images.  Limit to the
+             * known-unallocated area [sector_num, sector_num+n).  */
+            ret = bdrv_is_allocated_above(bs->backing_hd, base,
+                                          sector_num, n, &n);
+
+            /* Finish early if end of backing file has been reached */
+            if (ret == 0 && n == 0) {
+                n = end - sector_num;
+            }
+
+            copy = (ret == 1);
+        }
+        trace_stream_one_iteration(s, sector_num, n, ret);
+        if (copy) {
+            if (s->common.speed) {
+                delay_ns = ratelimit_calculate_delay(&s->limit, n);
+                if (delay_ns > 0) {
+                    goto wait;
+                }
+            }
+            ret = stream_populate(bs, sector_num, n, buf);
+        }
+        if (ret < 0) {
+            BlockErrorAction action =
+                block_job_error_action(&s->common, s->common.bs, s->on_error,
+                                       true, -ret);
+            if (action == BLOCK_ERROR_ACTION_STOP) {
+                n = 0;
+                continue;
+            }
+            if (error == 0) {
+                error = ret;
+            }
+            if (action == BLOCK_ERROR_ACTION_REPORT) {
+                break;
+            }
+        }
+        ret = 0;
+
+        /* Publish progress */
+        s->common.offset += n * BDRV_SECTOR_SIZE;
+    }
+
+    if (!base) {
+        bdrv_disable_copy_on_read(bs);
+    }
+
+    /* Do not remove the backing file if an error was there but ignored.  */
+    ret = error;
+
+    qemu_vfree(buf);
+
+    /* Modify backing chain and close BDSes in main loop */
+    data = g_malloc(sizeof(*data));
+    data->ret = ret;
+    data->reached_end = sector_num == end;
+    block_job_defer_to_main_loop(&s->common, stream_complete, data);
+}
+
+static void stream_set_speed(BlockJob *job, int64_t speed, Error **errp)
+{
+    StreamBlockJob *s = container_of(job, StreamBlockJob, common);
+
+    if (speed < 0) {
+        error_setg(errp, QERR_INVALID_PARAMETER, "speed");
+        return;
+    }
+    ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME);
+}
+
+static const BlockJobDriver stream_job_driver = {
+    .instance_size = sizeof(StreamBlockJob),
+    .job_type      = BLOCK_JOB_TYPE_STREAM,
+    .set_speed     = stream_set_speed,
+};
+
+void stream_start(BlockDriverState *bs, BlockDriverState *base,
+                  const char *backing_file_str, int64_t speed,
+                  BlockdevOnError on_error,
+                  BlockCompletionFunc *cb,
+                  void *opaque, Error **errp)
+{
+    StreamBlockJob *s;
+
+    if ((on_error == BLOCKDEV_ON_ERROR_STOP ||
+         on_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
+        !bdrv_iostatus_is_enabled(bs)) {
+        error_setg(errp, QERR_INVALID_PARAMETER, "on-error");
+        return;
+    }
+
+    s = block_job_create(&stream_job_driver, bs, speed, cb, opaque, errp);
+    if (!s) {
+        return;
+    }
+
+    s->base = base;
+    s->backing_file_str = g_strdup(backing_file_str);
+
+    s->on_error = on_error;
+    s->common.co = qemu_coroutine_create(stream_run);
+    trace_stream_start(bs, base, s, s->common.co, opaque);
+    qemu_coroutine_enter(s->common.co, s);
+}