[Qemu-devel] [PULL 0/4] Block patches

[Qemu-devel] [PULL 0/4] Block patches

[Stefan Hajnoczi]

The following changes since commit 14c7d99333e4a474c65bdae6f99aa8837e8078e6:

  Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20160714' into staging (2016-07-14 17:32:53 +0100)

are available in the git repository at:

  git://github.com/stefanha/qemu.git tags/block-pull-request

for you to fetch changes up to 325e00006139a30a4c747cf35489ea5bee8da272:

  linux-aio: prevent submitting more than MAX_EVENTS (2016-07-15 12:45:47 +0100)

----------------------------------------------------------------

----------------------------------------------------------------

Cao jin (1):
  aio_ctx_check: follow CODING_STYLE

Paolo Bonzini (1):
  linux-aio: share one LinuxAioState within an AioContext

Roman Pen (1):
  linux-aio: prevent submitting more than MAX_EVENTS

Vladimir Sementsov-Ogievskiy (1):
  spec/parallels: fix a mistake

 async.c                  |  25 +++++++++-
 block/linux-aio.c        |  36 ++++++++------
 block/raw-aio.h          |  68 ---------------------------
 block/raw-posix.c        | 119 ++++++-----------------------------------------
 block/raw-win32.c        |   2 +-
 docs/specs/parallels.txt |   2 +-
 include/block/aio.h      |  13 ++++++
 include/block/raw-aio.h  |  68 +++++++++++++++++++++++++++
 8 files changed, 143 insertions(+), 190 deletions(-)
 delete mode 100644 block/raw-aio.h
 create mode 100644 include/block/raw-aio.h

-- 
2.7.4

[Qemu-devel] [PULL 1/4] spec/parallels: fix a mistake

[Stefan Hajnoczi]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

We have only one flag for now - Empty Image flag. The patch fixes unused
bits specification and marks bit 1 as usused.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 docs/specs/parallels.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/specs/parallels.txt b/docs/specs/parallels.txt
index b4fe229..e9271eb 100644
--- a/docs/specs/parallels.txt
+++ b/docs/specs/parallels.txt
@@ -94,7 +94,7 @@ Bytes:
               Bit 0: Empty Image bit. If set, the image should be
                      considered clear.
 
-              Bits 2-31: Unused.
+              Bits 1-31: Unused.
 
   56 - 63:    ext_off
               Format Extension offset, an offset, in sectors, from the start of
-- 
2.7.4

[Qemu-devel] [PULL 2/4] linux-aio: share one LinuxAioState within an AioContext

[Stefan Hajnoczi]

From: Paolo Bonzini <pbonzini@redhat.com>

This has better performance because it executes fewer system calls
and does not use a bottom half per disk.

Originally proposed by Ming Lei.

Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1467650000-51385-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 async.c                 |  23 ++++++++++
 block/linux-aio.c       |  10 ++--
 block/raw-aio.h         |  68 ---------------------------
 block/raw-posix.c       | 119 ++++++------------------------------------------
 block/raw-win32.c       |   2 +-
 include/block/aio.h     |  13 ++++++
 include/block/raw-aio.h |  68 +++++++++++++++++++++++++++
 7 files changed, 125 insertions(+), 178 deletions(-)
 delete mode 100644 block/raw-aio.h
 create mode 100644 include/block/raw-aio.h

diff --git a/async.c b/async.c
index b4bf205..6caa98c 100644
--- a/async.c
+++ b/async.c
@@ -29,6 +29,7 @@
 #include "block/thread-pool.h"
 #include "qemu/main-loop.h"
 #include "qemu/atomic.h"
+#include "block/raw-aio.h"
 
 /***********************************************************/
 /* bottom halves (can be seen as timers which expire ASAP) */
@@ -242,6 +243,14 @@ aio_ctx_finalize(GSource     *source)
     qemu_bh_delete(ctx->notify_dummy_bh);
     thread_pool_free(ctx->thread_pool);
 
+#ifdef CONFIG_LINUX_AIO
+    if (ctx->linux_aio) {
+        laio_detach_aio_context(ctx->linux_aio, ctx);
+        laio_cleanup(ctx->linux_aio);
+        ctx->linux_aio = NULL;
+    }
+#endif
+
     qemu_mutex_lock(&ctx->bh_lock);
     while (ctx->first_bh) {
         QEMUBH *next = ctx->first_bh->next;
@@ -282,6 +291,17 @@ ThreadPool *aio_get_thread_pool(AioContext *ctx)
     return ctx->thread_pool;
 }
 
+#ifdef CONFIG_LINUX_AIO
+LinuxAioState *aio_get_linux_aio(AioContext *ctx)
+{
+    if (!ctx->linux_aio) {
+        ctx->linux_aio = laio_init();
+        laio_attach_aio_context(ctx->linux_aio, ctx);
+    }
+    return ctx->linux_aio;
+}
+#endif
+
 void aio_notify(AioContext *ctx)
 {
     /* Write e.g. bh->scheduled before reading ctx->notify_me.  Pairs
@@ -345,6 +365,9 @@ AioContext *aio_context_new(Error **errp)
                            false,
                            (EventNotifierHandler *)
                            event_notifier_dummy_cb);
+#ifdef CONFIG_LINUX_AIO
+    ctx->linux_aio = NULL;
+#endif
     ctx->thread_pool = NULL;
     qemu_mutex_init(&ctx->bh_lock);
     rfifolock_init(&ctx->lock, aio_rfifolock_cb, ctx);
diff --git a/block/linux-aio.c b/block/linux-aio.c
index 5c104bd..1d702a5 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -50,6 +50,8 @@ typedef struct {
 } LaioQueue;
 
 struct LinuxAioState {
+    AioContext *aio_context;
+
     io_context_t ctx;
     EventNotifier e;
 
@@ -227,15 +229,14 @@ static void ioq_submit(LinuxAioState *s)
 
 void laio_io_plug(BlockDriverState *bs, LinuxAioState *s)
 {
-    assert(!s->io_q.plugged);
-    s->io_q.plugged = 1;
+    s->io_q.plugged++;
 }
 
 void laio_io_unplug(BlockDriverState *bs, LinuxAioState *s)
 {
     assert(s->io_q.plugged);
-    s->io_q.plugged = 0;
-    if (!s->io_q.blocked && !QSIMPLEQ_EMPTY(&s->io_q.pending)) {
+    if (--s->io_q.plugged == 0 &&
+        !s->io_q.blocked && !QSIMPLEQ_EMPTY(&s->io_q.pending)) {
         ioq_submit(s);
     }
 }
@@ -325,6 +326,7 @@ void laio_detach_aio_context(LinuxAioState *s, AioContext *old_context)
 
 void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
 {
+    s->aio_context = new_context;
     s->completion_bh = aio_bh_new(new_context, qemu_laio_completion_bh, s);
     aio_set_event_notifier(new_context, &s->e, false,
                            qemu_laio_completion_cb);
diff --git a/block/raw-aio.h b/block/raw-aio.h
deleted file mode 100644
index a4cdbbf..0000000
--- a/block/raw-aio.h
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Declarations for AIO in the raw protocol
- *
- * Copyright IBM, Corp. 2008
- *
- * Authors:
- *  Anthony Liguori   <aliguori@us.ibm.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2.  See
- * the COPYING file in the top-level directory.
- *
- * Contributions after 2012-01-13 are licensed under the terms of the
- * GNU GPL, version 2 or (at your option) any later version.
- */
-#ifndef QEMU_RAW_AIO_H
-#define QEMU_RAW_AIO_H
-
-#include "qemu/coroutine.h"
-#include "qemu/iov.h"
-
-/* AIO request types */
-#define QEMU_AIO_READ         0x0001
-#define QEMU_AIO_WRITE        0x0002
-#define QEMU_AIO_IOCTL        0x0004
-#define QEMU_AIO_FLUSH        0x0008
-#define QEMU_AIO_DISCARD      0x0010
-#define QEMU_AIO_WRITE_ZEROES 0x0020
-#define QEMU_AIO_TYPE_MASK \
-        (QEMU_AIO_READ|QEMU_AIO_WRITE|QEMU_AIO_IOCTL|QEMU_AIO_FLUSH| \
-         QEMU_AIO_DISCARD|QEMU_AIO_WRITE_ZEROES)
-
-/* AIO flags */
-#define QEMU_AIO_MISALIGNED   0x1000
-#define QEMU_AIO_BLKDEV       0x2000
-
-
-/* linux-aio.c - Linux native implementation */
-#ifdef CONFIG_LINUX_AIO
-typedef struct LinuxAioState LinuxAioState;
-LinuxAioState *laio_init(void);
-void laio_cleanup(LinuxAioState *s);
-int coroutine_fn laio_co_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
-                                uint64_t offset, QEMUIOVector *qiov, int type);
-BlockAIOCB *laio_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
-        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockCompletionFunc *cb, void *opaque, int type);
-void laio_detach_aio_context(LinuxAioState *s, AioContext *old_context);
-void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context);
-void laio_io_plug(BlockDriverState *bs, LinuxAioState *s);
-void laio_io_unplug(BlockDriverState *bs, LinuxAioState *s);
-#endif
-
-#ifdef _WIN32
-typedef struct QEMUWin32AIOState QEMUWin32AIOState;
-QEMUWin32AIOState *win32_aio_init(void);
-void win32_aio_cleanup(QEMUWin32AIOState *aio);
-int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile);
-BlockAIOCB *win32_aio_submit(BlockDriverState *bs,
-        QEMUWin32AIOState *aio, HANDLE hfile,
-        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockCompletionFunc *cb, void *opaque, int type);
-void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
-                                  AioContext *old_context);
-void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
-                                  AioContext *new_context);
-#endif
-
-#endif /* QEMU_RAW_AIO_H */
diff --git a/block/raw-posix.c b/block/raw-posix.c
index d1c3bd8..20f4d7a 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -32,7 +32,7 @@
 #include "trace.h"
 #include "block/thread-pool.h"
 #include "qemu/iov.h"
-#include "raw-aio.h"
+#include "block/raw-aio.h"
 #include "qapi/util.h"
 #include "qapi/qmp/qstring.h"
 
@@ -137,10 +137,6 @@ typedef struct BDRVRawState {
     int open_flags;
     size_t buf_align;
 
-#ifdef CONFIG_LINUX_AIO
-    int use_aio;
-    LinuxAioState *aio_ctx;
-#endif
 #ifdef CONFIG_XFS
     bool is_xfs:1;
 #endif
@@ -154,9 +150,6 @@ typedef struct BDRVRawState {
 typedef struct BDRVRawReopenState {
     int fd;
     int open_flags;
-#ifdef CONFIG_LINUX_AIO
-    int use_aio;
-#endif
 } BDRVRawReopenState;
 
 static int fd_open(BlockDriverState *bs);
@@ -374,58 +367,15 @@ static void raw_parse_flags(int bdrv_flags, int *open_flags)
     }
 }
 
-static void raw_detach_aio_context(BlockDriverState *bs)
-{
-#ifdef CONFIG_LINUX_AIO
-    BDRVRawState *s = bs->opaque;
-
-    if (s->use_aio) {
-        laio_detach_aio_context(s->aio_ctx, bdrv_get_aio_context(bs));
-    }
-#endif
-}
-
-static void raw_attach_aio_context(BlockDriverState *bs,
-                                   AioContext *new_context)
-{
-#ifdef CONFIG_LINUX_AIO
-    BDRVRawState *s = bs->opaque;
-
-    if (s->use_aio) {
-        laio_attach_aio_context(s->aio_ctx, new_context);
-    }
-#endif
-}
-
 #ifdef CONFIG_LINUX_AIO
-static int raw_set_aio(LinuxAioState **aio_ctx, int *use_aio, int bdrv_flags)
+static bool raw_use_aio(int bdrv_flags)
 {
-    int ret = -1;
-    assert(aio_ctx != NULL);
-    assert(use_aio != NULL);
     /*
      * Currently Linux do AIO only for files opened with O_DIRECT
      * specified so check NOCACHE flag too
      */
-    if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
-                      (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {
-
-        /* if non-NULL, laio_init() has already been run */
-        if (*aio_ctx == NULL) {
-            *aio_ctx = laio_init();
-            if (!*aio_ctx) {
-                goto error;
-            }
-        }
-        *use_aio = 1;
-    } else {
-        *use_aio = 0;
-    }
-
-    ret = 0;
-
-error:
-    return ret;
+    return (bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==
+                         (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO);
 }
 #endif
 
@@ -494,13 +444,7 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
     s->fd = fd;
 
 #ifdef CONFIG_LINUX_AIO
-    if (raw_set_aio(&s->aio_ctx, &s->use_aio, bdrv_flags)) {
-        qemu_close(fd);
-        ret = -errno;
-        error_setg_errno(errp, -ret, "Could not set AIO state");
-        goto fail;
-    }
-    if (!s->use_aio && (bdrv_flags & BDRV_O_NATIVE_AIO)) {
+    if (!raw_use_aio(bdrv_flags) && (bdrv_flags & BDRV_O_NATIVE_AIO)) {
         error_setg(errp, "aio=native was specified, but it requires "
                          "cache.direct=on, which was not specified.");
         ret = -EINVAL;
@@ -567,8 +511,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
     }
 #endif
 
-    raw_attach_aio_context(bs, bdrv_get_aio_context(bs));
-
     ret = 0;
 fail:
     if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {
@@ -603,18 +545,6 @@ static int raw_reopen_prepare(BDRVReopenState *state,
     state->opaque = g_new0(BDRVRawReopenState, 1);
     raw_s = state->opaque;
 
-#ifdef CONFIG_LINUX_AIO
-    raw_s->use_aio = s->use_aio;
-
-    /* we can use s->aio_ctx instead of a copy, because the use_aio flag is
-     * valid in the 'false' condition even if aio_ctx is set, and raw_set_aio()
-     * won't override aio_ctx if aio_ctx is non-NULL */
-    if (raw_set_aio(&s->aio_ctx, &raw_s->use_aio, state->flags)) {
-        error_setg(errp, "Could not set AIO state");
-        return -1;
-    }
-#endif
-
     if (s->type == FTYPE_CD) {
         raw_s->open_flags |= O_NONBLOCK;
     }
@@ -689,9 +619,6 @@ static void raw_reopen_commit(BDRVReopenState *state)
 
     qemu_close(s->fd);
     s->fd = raw_s->fd;
-#ifdef CONFIG_LINUX_AIO
-    s->use_aio = raw_s->use_aio;
-#endif
 
     g_free(state->opaque);
     state->opaque = NULL;
@@ -1329,9 +1256,10 @@ static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
         if (!bdrv_qiov_is_aligned(bs, qiov)) {
             type |= QEMU_AIO_MISALIGNED;
 #ifdef CONFIG_LINUX_AIO
-        } else if (s->use_aio) {
+        } else if (bs->open_flags & BDRV_O_NATIVE_AIO) {
+            LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
             assert(qiov->size == bytes);
-            return laio_co_submit(bs, s->aio_ctx, s->fd, offset, qiov, type);
+            return laio_co_submit(bs, aio, s->fd, offset, qiov, type);
 #endif
         }
     }
@@ -1357,9 +1285,9 @@ static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
 static void raw_aio_plug(BlockDriverState *bs)
 {
 #ifdef CONFIG_LINUX_AIO
-    BDRVRawState *s = bs->opaque;
-    if (s->use_aio) {
-        laio_io_plug(bs, s->aio_ctx);
+    if (bs->open_flags & BDRV_O_NATIVE_AIO) {
+        LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
+        laio_io_plug(bs, aio);
     }
 #endif
 }
@@ -1367,9 +1295,9 @@ static void raw_aio_plug(BlockDriverState *bs)
 static void raw_aio_unplug(BlockDriverState *bs)
 {
 #ifdef CONFIG_LINUX_AIO
-    BDRVRawState *s = bs->opaque;
-    if (s->use_aio) {
-        laio_io_unplug(bs, s->aio_ctx);
+    if (bs->open_flags & BDRV_O_NATIVE_AIO) {
+        LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
+        laio_io_unplug(bs, aio);
     }
 #endif
 }
@@ -1389,13 +1317,6 @@ static void raw_close(BlockDriverState *bs)
 {
     BDRVRawState *s = bs->opaque;
 
-    raw_detach_aio_context(bs);
-
-#ifdef CONFIG_LINUX_AIO
-    if (s->use_aio) {
-        laio_cleanup(s->aio_ctx);
-    }
-#endif
     if (s->fd >= 0) {
         qemu_close(s->fd);
         s->fd = -1;
@@ -1954,9 +1875,6 @@ BlockDriver bdrv_file = {
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 
-    .bdrv_detach_aio_context = raw_detach_aio_context,
-    .bdrv_attach_aio_context = raw_attach_aio_context,
-
     .create_opts = &raw_create_opts,
 };
 
@@ -2402,9 +2320,6 @@ static BlockDriver bdrv_host_device = {
     .bdrv_probe_blocksizes = hdev_probe_blocksizes,
     .bdrv_probe_geometry = hdev_probe_geometry,
 
-    .bdrv_detach_aio_context = raw_detach_aio_context,
-    .bdrv_attach_aio_context = raw_attach_aio_context,
-
     /* generic scsi device */
 #ifdef __linux__
     .bdrv_aio_ioctl     = hdev_aio_ioctl,
@@ -2524,9 +2439,6 @@ static BlockDriver bdrv_host_cdrom = {
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 
-    .bdrv_detach_aio_context = raw_detach_aio_context,
-    .bdrv_attach_aio_context = raw_attach_aio_context,
-
     /* removable device support */
     .bdrv_is_inserted   = cdrom_is_inserted,
     .bdrv_eject         = cdrom_eject,
@@ -2657,9 +2569,6 @@ static BlockDriver bdrv_host_cdrom = {
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 
-    .bdrv_detach_aio_context = raw_detach_aio_context,
-    .bdrv_attach_aio_context = raw_attach_aio_context,
-
     /* removable device support */
     .bdrv_is_inserted   = cdrom_is_inserted,
     .bdrv_eject         = cdrom_eject,
diff --git a/block/raw-win32.c b/block/raw-win32.c
index 62edb1a..9b813d9 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -27,7 +27,7 @@
 #include "qemu/timer.h"
 #include "block/block_int.h"
 #include "qemu/module.h"
-#include "raw-aio.h"
+#include "block/raw-aio.h"
 #include "trace.h"
 #include "block/thread-pool.h"
 #include "qemu/iov.h"
diff --git a/include/block/aio.h b/include/block/aio.h
index 88a64ee..afd72a7 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -47,6 +47,9 @@ typedef struct AioHandler AioHandler;
 typedef void QEMUBHFunc(void *opaque);
 typedef void IOHandler(void *opaque);
 
+struct ThreadPool;
+struct LinuxAioState;
+
 struct AioContext {
     GSource source;
 
@@ -119,6 +122,13 @@ struct AioContext {
     /* Thread pool for performing work and receiving completion callbacks */
     struct ThreadPool *thread_pool;
 
+#ifdef CONFIG_LINUX_AIO
+    /* State for native Linux AIO.  Uses aio_context_acquire/release for
+     * locking.
+     */
+    struct LinuxAioState *linux_aio;
+#endif
+
     /* TimerLists for calling timers - one per clock type */
     QEMUTimerListGroup tlg;
 
@@ -335,6 +345,9 @@ GSource *aio_get_g_source(AioContext *ctx);
 /* Return the ThreadPool bound to this AioContext */
 struct ThreadPool *aio_get_thread_pool(AioContext *ctx);
 
+/* Return the LinuxAioState bound to this AioContext */
+struct LinuxAioState *aio_get_linux_aio(AioContext *ctx);
+
 /**
  * aio_timer_new:
  * @ctx: the aio context
diff --git a/include/block/raw-aio.h b/include/block/raw-aio.h
new file mode 100644
index 0000000..a4cdbbf
--- /dev/null
+++ b/include/block/raw-aio.h
@@ -0,0 +1,68 @@
+/*
+ * Declarations for AIO in the raw protocol
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+#ifndef QEMU_RAW_AIO_H
+#define QEMU_RAW_AIO_H
+
+#include "qemu/coroutine.h"
+#include "qemu/iov.h"
+
+/* AIO request types */
+#define QEMU_AIO_READ         0x0001
+#define QEMU_AIO_WRITE        0x0002
+#define QEMU_AIO_IOCTL        0x0004
+#define QEMU_AIO_FLUSH        0x0008
+#define QEMU_AIO_DISCARD      0x0010
+#define QEMU_AIO_WRITE_ZEROES 0x0020
+#define QEMU_AIO_TYPE_MASK \
+        (QEMU_AIO_READ|QEMU_AIO_WRITE|QEMU_AIO_IOCTL|QEMU_AIO_FLUSH| \
+         QEMU_AIO_DISCARD|QEMU_AIO_WRITE_ZEROES)
+
+/* AIO flags */
+#define QEMU_AIO_MISALIGNED   0x1000
+#define QEMU_AIO_BLKDEV       0x2000
+
+
+/* linux-aio.c - Linux native implementation */
+#ifdef CONFIG_LINUX_AIO
+typedef struct LinuxAioState LinuxAioState;
+LinuxAioState *laio_init(void);
+void laio_cleanup(LinuxAioState *s);
+int coroutine_fn laio_co_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
+                                uint64_t offset, QEMUIOVector *qiov, int type);
+BlockAIOCB *laio_submit(BlockDriverState *bs, LinuxAioState *s, int fd,
+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+        BlockCompletionFunc *cb, void *opaque, int type);
+void laio_detach_aio_context(LinuxAioState *s, AioContext *old_context);
+void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context);
+void laio_io_plug(BlockDriverState *bs, LinuxAioState *s);
+void laio_io_unplug(BlockDriverState *bs, LinuxAioState *s);
+#endif
+
+#ifdef _WIN32
+typedef struct QEMUWin32AIOState QEMUWin32AIOState;
+QEMUWin32AIOState *win32_aio_init(void);
+void win32_aio_cleanup(QEMUWin32AIOState *aio);
+int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile);
+BlockAIOCB *win32_aio_submit(BlockDriverState *bs,
+        QEMUWin32AIOState *aio, HANDLE hfile,
+        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+        BlockCompletionFunc *cb, void *opaque, int type);
+void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
+                                  AioContext *old_context);
+void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
+                                  AioContext *new_context);
+#endif
+
+#endif /* QEMU_RAW_AIO_H */
-- 
2.7.4

[Qemu-devel] [PULL 3/4] aio_ctx_check: follow CODING_STYLE

[Stefan Hajnoczi]

From: Cao jin <caoj.fnst@cn.fujitsu.com>

replace tab with spaces

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Message-id: 1468501843-14927-1-git-send-email-caoj.fnst@cn.fujitsu.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 async.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/async.c b/async.c
index 6caa98c..0e0efc3 100644
--- a/async.c
+++ b/async.c
@@ -218,7 +218,7 @@ aio_ctx_check(GSource *source)
     for (bh = ctx->first_bh; bh; bh = bh->next) {
         if (!bh->deleted && bh->scheduled) {
             return true;
-	}
+        }
     }
     return aio_pending(ctx) || (timerlistgroup_deadline_ns(&ctx->tlg) == 0);
 }
-- 
2.7.4

[Qemu-devel] [PULL 4/4] linux-aio: prevent submitting more than MAX_EVENTS

[Stefan Hajnoczi]

From: Roman Pen <roman.penyaev@profitbricks.com>

Invoking io_setup(MAX_EVENTS) we ask kernel to create ring buffer for us
with specified number of events.  But kernel ring buffer allocation logic
is a bit tricky (ring buffer is page size aligned + some percpu allocation
are required) so eventually more than requested events number is allocated.

>From a userspace side we have to follow the convention and should not try
to io_submit() more or logic, which consumes completed events, should be
changed accordingly.  The pitfall is in the following sequence:

    MAX_EVENTS = 128
    io_setup(MAX_EVENTS)

    io_submit(MAX_EVENTS)
    io_submit(MAX_EVENTS)

    /* now 256 events are in-flight */

    io_getevents(MAX_EVENTS) = 128

    /* we can handle only 128 events at once, to be sure
     * that nothing is pended the io_getevents(MAX_EVENTS)
     * call must be invoked once more or hang will happen. */

To prevent the hang or reiteration of io_getevents() call this patch
restricts the number of in-flights, which is now limited to MAX_EVENTS.

Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1468415004-31755-1-git-send-email-roman.penyaev@profitbricks.com
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: qemu-devel@nongnu.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/linux-aio.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/block/linux-aio.c b/block/linux-aio.c
index 1d702a5..de3548f 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -28,8 +28,6 @@
  */
 #define MAX_EVENTS 128
 
-#define MAX_QUEUED_IO  128
-
 struct qemu_laiocb {
     BlockAIOCB common;
     Coroutine *co;
@@ -44,7 +42,8 @@ struct qemu_laiocb {
 
 typedef struct {
     int plugged;
-    unsigned int n;
+    unsigned int in_queue;
+    unsigned int in_flight;
     bool blocked;
     QSIMPLEQ_HEAD(, qemu_laiocb) pending;
 } LaioQueue;
@@ -131,6 +130,7 @@ static void qemu_laio_completion_bh(void *opaque)
             s->event_max = 0;
             return; /* no more events */
         }
+        s->io_q.in_flight -= s->event_max;
     }
 
     /* Reschedule so nested event loops see currently pending completions */
@@ -192,7 +192,8 @@ static void ioq_init(LaioQueue *io_q)
 {
     QSIMPLEQ_INIT(&io_q->pending);
     io_q->plugged = 0;
-    io_q->n = 0;
+    io_q->in_queue = 0;
+    io_q->in_flight = 0;
     io_q->blocked = false;
 }
 
@@ -200,14 +201,17 @@ static void ioq_submit(LinuxAioState *s)
 {
     int ret, len;
     struct qemu_laiocb *aiocb;
-    struct iocb *iocbs[MAX_QUEUED_IO];
+    struct iocb *iocbs[MAX_EVENTS];
     QSIMPLEQ_HEAD(, qemu_laiocb) completed;
 
     do {
+        if (s->io_q.in_flight >= MAX_EVENTS) {
+            break;
+        }
         len = 0;
         QSIMPLEQ_FOREACH(aiocb, &s->io_q.pending, next) {
             iocbs[len++] = &aiocb->iocb;
-            if (len == MAX_QUEUED_IO) {
+            if (s->io_q.in_flight + len >= MAX_EVENTS) {
                 break;
             }
         }
@@ -220,11 +224,12 @@ static void ioq_submit(LinuxAioState *s)
             abort();
         }
 
-        s->io_q.n -= ret;
+        s->io_q.in_flight += ret;
+        s->io_q.in_queue  -= ret;
         aiocb = container_of(iocbs[ret - 1], struct qemu_laiocb, iocb);
         QSIMPLEQ_SPLIT_AFTER(&s->io_q.pending, aiocb, next, &completed);
     } while (ret == len && !QSIMPLEQ_EMPTY(&s->io_q.pending));
-    s->io_q.blocked = (s->io_q.n > 0);
+    s->io_q.blocked = (s->io_q.in_queue > 0);
 }
 
 void laio_io_plug(BlockDriverState *bs, LinuxAioState *s)
@@ -264,9 +269,10 @@ static int laio_do_submit(int fd, struct qemu_laiocb *laiocb, off_t offset,
     io_set_eventfd(&laiocb->iocb, event_notifier_get_fd(&s->e));
 
     QSIMPLEQ_INSERT_TAIL(&s->io_q.pending, laiocb, next);
-    s->io_q.n++;
+    s->io_q.in_queue++;
     if (!s->io_q.blocked &&
-        (!s->io_q.plugged || s->io_q.n >= MAX_QUEUED_IO)) {
+        (!s->io_q.plugged ||
+         s->io_q.in_flight + s->io_q.in_queue >= MAX_EVENTS)) {
         ioq_submit(s);
     }
 
-- 
2.7.4

Re: [Qemu-devel] [PULL 0/4] Block patches

[Peter Maydell]

On 15 July 2016 at 18:59, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> The following changes since commit 14c7d99333e4a474c65bdae6f99aa8837e8078e6:
>
>   Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20160714' into staging (2016-07-14 17:32:53 +0100)
>
> are available in the git repository at:
>
>   git://github.com/stefanha/qemu.git tags/block-pull-request
>
> for you to fetch changes up to 325e00006139a30a4c747cf35489ea5bee8da272:
>
>   linux-aio: prevent submitting more than MAX_EVENTS (2016-07-15 12:45:47 +0100)
>
> ----------------------------------------------------------------
>
> ----------------------------------------------------------------

I'm afraid this fails to build for w32:

/home/petmay01/linaro/qemu-for-merges/block/win32-aio.c:30:21: fatal
error: raw-aio.h: No such file or directory
 #include "raw-aio.h"
                     ^
compilation terminated.

Looks like that should be "block/raw-aio.h".

thanks
-- PMM

Re: [Qemu-devel] [PULL 0/4] Block patches

[Paolo Bonzini]

On 18/07/2016 12:23, Peter Maydell wrote:
> I'm afraid this fails to build for w32:
> 
> /home/petmay01/linaro/qemu-for-merges/block/win32-aio.c:30:21: fatal
> error: raw-aio.h: No such file or directory
>  #include "raw-aio.h"
>                      ^
> compilation terminated.
> 
> Looks like that should be "block/raw-aio.h".

But that's in the patch:

diff --git a/block/raw-win32.c b/block/raw-win32.c
index 62edb1a..9b813d9 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -27,7 +27,7 @@
 #include "qemu/timer.h"
 #include "block/block_int.h"
 #include "qemu/module.h"
-#include "raw-aio.h"
+#include "block/raw-aio.h"
 #include "trace.h"
 #include "block/thread-pool.h"
 #include "qemu/iov.h"

Did you get a conflict, or did git screw up some resolution?

Paolo

Re: [Qemu-devel] [PULL 0/4] Block patches

[Peter Maydell]

On 18 July 2016 at 15:57, Paolo Bonzini <pbonzini@redhat.com> wrote:
>
>
> On 18/07/2016 12:23, Peter Maydell wrote:
>> I'm afraid this fails to build for w32:
>>
>> /home/petmay01/linaro/qemu-for-merges/block/win32-aio.c:30:21: fatal
>> error: raw-aio.h: No such file or directory
>>  #include "raw-aio.h"
>>                      ^
>> compilation terminated.
>>
>> Looks like that should be "block/raw-aio.h".
>
> But that's in the patch:
>
> diff --git a/block/raw-win32.c b/block/raw-win32.c

This is not the .c file which is mentioned in the above
compiler error message :-)

thanks
-- PMM

Re: [Qemu-devel] [PULL 0/4] Block patches

[Stefan Hajnoczi]

[-- Attachment #1: Type: text/plain, Size: 782 bytes --]

On Mon, Jul 18, 2016 at 03:58:29PM +0100, Peter Maydell wrote:
> On 18 July 2016 at 15:57, Paolo Bonzini <pbonzini@redhat.com> wrote:
> >
> >
> > On 18/07/2016 12:23, Peter Maydell wrote:
> >> I'm afraid this fails to build for w32:
> >>
> >> /home/petmay01/linaro/qemu-for-merges/block/win32-aio.c:30:21: fatal
> >> error: raw-aio.h: No such file or directory
> >>  #include "raw-aio.h"
> >>                      ^
> >> compilation terminated.
> >>
> >> Looks like that should be "block/raw-aio.h".
> >
> > But that's in the patch:
> >
> > diff --git a/block/raw-win32.c b/block/raw-win32.c
> 
> This is not the .c file which is mentioned in the above
> compiler error message :-)

I resolved the issue yesterday and sent a new block pull request.

Stefan

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