qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [PATCH 5/6] push down vector linearization to posix-aio-com


From: Christoph Hellwig
Subject: [Qemu-devel] [PATCH 5/6] push down vector linearization to posix-aio-compat.c
Date: Sat, 14 Mar 2009 20:30:53 +0100
User-agent: Mutt/1.3.28i


Make all AIO requests vectored and defer linearization until the actual
I/O thread.  This prepares for using native preadv/pwritev.

Also enables asynchronous direct I/O by handling that case in the I/O thread.

For now disables support for scsi-generic requests until I figure a
way to fit it into the new world order.

Win32 support is untested and uncompiled.  Then again I can't even find
a know to turn on win32 aio support.

Qcow and qcow2 propably want to be adopted to directly deal with multi-segment
requests, but that can be implemented later.


Signed-off-by: Christoph Hellwig <address@hidden>

Index: qemu/block.c
===================================================================
--- qemu.orig/block.c   2009-03-14 18:08:40.000000000 +0100
+++ qemu/block.c        2009-03-14 18:08:41.000000000 +0100
@@ -51,19 +51,19 @@ typedef struct BlockDriverAIOCBSync {
     BlockDriverAIOCB common;
     QEMUBH *bh;
     int ret;
+    /* vector translation state */
+    struct iovec *iov;
+    int nr_iov;
+    int size;
+    uint8_t *bounce;
+    int is_write;
 } BlockDriverAIOCBSync;
 
-static BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque);
-static BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);
-static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque);
-static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, int64_t 
sector_num,
+        struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);
 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
@@ -142,10 +142,10 @@ void path_combine(char *dest, int dest_s
 
 static void bdrv_register(BlockDriver *bdrv)
 {
-    if (!bdrv->bdrv_aio_read) {
+    if (!bdrv->bdrv_aio_readv) {
         /* add AIO emulation layer */
-        bdrv->bdrv_aio_read = bdrv_aio_read_em;
-        bdrv->bdrv_aio_write = bdrv_aio_write_em;
+        bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
+        bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
         bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
         bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
     } else if (!bdrv->bdrv_read) {
@@ -1250,84 +1250,10 @@ char *bdrv_snapshot_dump(char *buf, int 
 /**************************************************************/
 /* async I/Os */
 
-typedef struct VectorTranslationState {
-    struct iovec *iov;
-    int nr_iov;
-    int size;
-    uint8_t *bounce;
-    int is_write;
-    BlockDriverAIOCB *aiocb;
-    BlockDriverAIOCB *this_aiocb;
-} VectorTranslationState;
-
-static void bdrv_aio_rw_vector_cb(void *opaque, int ret)
-{
-    VectorTranslationState *s = opaque;
-
-    if (!s->is_write) {
-        iovec_from_buffer(s->iov, s->nr_iov, s->bounce, s->size);
-    }
-    qemu_vfree(s->bounce);
-    s->this_aiocb->cb(s->this_aiocb->opaque, ret);
-    qemu_aio_release(s->this_aiocb);
-}
-
-static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
-                                            int64_t sector_num,
-                                            struct iovec *iov,
-                                           int nr_iov,
-                                            int nb_sectors,
-                                            BlockDriverCompletionFunc *cb,
-                                            void *opaque,
-                                            int is_write)
-
-{
-    VectorTranslationState *s = qemu_mallocz(sizeof(*s));
-    BlockDriverAIOCB *aiocb = qemu_aio_get(bs, cb, opaque);
-
-    s->this_aiocb = aiocb;
-    s->iov = iov;
-    s->nr_iov = nr_iov;
-    s->size = nb_sectors * 512;
-    s->bounce = qemu_memalign(512, s->size);
-    s->is_write = is_write;
-    if (is_write) {
-        iovec_to_buffer(s->iov, s->nr_iov, s->bounce);
-        s->aiocb = bdrv_aio_write(bs, sector_num, s->bounce, nb_sectors,
-                                  bdrv_aio_rw_vector_cb, s);
-    } else {
-        s->aiocb = bdrv_aio_read(bs, sector_num, s->bounce, nb_sectors,
-                                 bdrv_aio_rw_vector_cb, s);
-    }
-    return aiocb;
-}
-
 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
                                  struct iovec *iov, int nr_iov, int nb_sectors,
                                  BlockDriverCompletionFunc *cb, void *opaque)
 {
-    if (bdrv_check_request(bs, sector_num, nb_sectors))
-        return NULL;
-
-    return bdrv_aio_rw_vector(bs, sector_num, iov, nr_iov, nb_sectors,
-                              cb, opaque, 0);
-}
-
-BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
-                                  struct iovec *iov, int nr_iov, int 
nb_sectors,
-                                  BlockDriverCompletionFunc *cb, void *opaque)
-{
-    if (bdrv_check_request(bs, sector_num, nb_sectors))
-        return NULL;
-
-    return bdrv_aio_rw_vector(bs, sector_num, iov, nr_iov, nb_sectors,
-                              cb, opaque, 1);
-}
-
-static BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t 
sector_num,
-                                uint8_t *buf, int nb_sectors,
-                                BlockDriverCompletionFunc *cb, void *opaque)
-{
     BlockDriver *drv = bs->drv;
     BlockDriverAIOCB *ret;
 
@@ -1336,7 +1262,8 @@ static BlockDriverAIOCB *bdrv_aio_read(B
     if (bdrv_check_request(bs, sector_num, nb_sectors))
         return NULL;
 
-    ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
+    ret = drv->bdrv_aio_readv(bs, sector_num, iov, nr_iov, nb_sectors,
+                              cb, opaque);
 
     if (ret) {
        /* Update stats even though technically transfer has not happened. */
@@ -1347,9 +1274,9 @@ static BlockDriverAIOCB *bdrv_aio_read(B
     return ret;
 }
 
-static BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t 
sector_num,
-                                 const uint8_t *buf, int nb_sectors,
-                                 BlockDriverCompletionFunc *cb, void *opaque)
+BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
+                                  struct iovec *iov, int nr_iov, int 
nb_sectors,
+                                  BlockDriverCompletionFunc *cb, void *opaque)
 {
     BlockDriver *drv = bs->drv;
     BlockDriverAIOCB *ret;
@@ -1361,7 +1288,8 @@ static BlockDriverAIOCB *bdrv_aio_write(
     if (bdrv_check_request(bs, sector_num, nb_sectors))
         return NULL;
 
-    ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
+    ret = drv->bdrv_aio_writev(bs, sector_num, iov, nr_iov, nb_sectors,
+                               cb, opaque);
 
     if (ret) {
        /* Update stats even though technically transfer has not happened. */
@@ -1376,11 +1304,6 @@ void bdrv_aio_cancel(BlockDriverAIOCB *a
 {
     BlockDriver *drv = acb->bs->drv;
 
-    if (acb->cb == bdrv_aio_rw_vector_cb) {
-        VectorTranslationState *s = acb->opaque;
-        acb = s->aiocb;
-    }
-
     drv->bdrv_aio_cancel(acb);
 }
 
@@ -1391,42 +1314,66 @@ void bdrv_aio_cancel(BlockDriverAIOCB *a
 static void bdrv_aio_bh_cb(void *opaque)
 {
     BlockDriverAIOCBSync *acb = opaque;
+
+    qemu_vfree(acb->bounce);
+
+    if (!acb->is_write)
+        iovec_from_buffer(acb->iov, acb->nr_iov, acb->bounce, acb->size);
     acb->common.cb(acb->common.opaque, acb->ret);
+
     qemu_aio_release(acb);
 }
 
-static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
+                                            int64_t sector_num,
+                                            struct iovec *iov,
+                                           int nr_iov,
+                                            int nb_sectors,
+                                            BlockDriverCompletionFunc *cb,
+                                            void *opaque,
+                                            int is_write)
+
 {
-    BlockDriverAIOCBSync *acb;
-    int ret;
+    BlockDriverAIOCBSync *acb = qemu_aio_get(bs, cb, opaque);
+
+    acb->is_write = is_write;
+    acb->iov = iov;
+    acb->nr_iov = nr_iov;
+    acb->size = nb_sectors * 512;
+    acb->bounce = qemu_memalign(512, acb->size);
 
-    acb = qemu_aio_get(bs, cb, opaque);
     if (!acb->bh)
         acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
-    ret = bdrv_read(bs, sector_num, buf, nb_sectors);
-    acb->ret = ret;
+
+    if (is_write) {
+        iovec_to_buffer(acb->iov, acb->nr_iov, acb->bounce);
+        acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
+    } else {
+        acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
+    }
+
     qemu_bh_schedule(acb->bh);
+
     return &acb->common;
 }
 
-static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
-    BlockDriverAIOCBSync *acb;
-    int ret;
+    return bdrv_aio_rw_vector(bs, sector_num, iov, nr_iov, nb_sectors,
+                              cb, opaque, 0);
+}
 
-    acb = qemu_aio_get(bs, cb, opaque);
-    if (!acb->bh)
-        acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
-    ret = bdrv_write(bs, sector_num, buf, nb_sectors);
-    acb->ret = ret;
-    qemu_bh_schedule(acb->bh);
-    return &acb->common;
+static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, int64_t 
sector_num,
+        struct iovec *iov, int nr_iov, int nb_sectors,
+        BlockDriverCompletionFunc *cb, void *opaque)
+{
+    return bdrv_aio_rw_vector(bs, sector_num, iov, nr_iov, nb_sectors,
+                              cb, opaque, 1);
 }
 
+
 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
 {
     BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
@@ -1449,10 +1396,13 @@ static int bdrv_read_em(BlockDriverState
 {
     int async_ret;
     BlockDriverAIOCB *acb;
+    struct iovec iov;
 
     async_ret = NOT_DONE;
-    acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
-                        bdrv_rw_em_cb, &async_ret);
+    iov.iov_base = buf;
+    iov.iov_len = nb_sectors * 512;
+    acb = bdrv_aio_readv(bs, sector_num, &iov, 1, nb_sectors,
+                         bdrv_rw_em_cb, &async_ret);
     if (acb == NULL)
         return -1;
 
@@ -1468,10 +1418,13 @@ static int bdrv_write_em(BlockDriverStat
 {
     int async_ret;
     BlockDriverAIOCB *acb;
+    struct iovec iov;
 
     async_ret = NOT_DONE;
-    acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
-                         bdrv_rw_em_cb, &async_ret);
+    iov.iov_base = (void *)buf;
+    iov.iov_len = nb_sectors * 512;
+    acb = bdrv_aio_writev(bs, sector_num, &iov, 1, nb_sectors,
+                          bdrv_rw_em_cb, &async_ret);
     if (acb == NULL)
         return -1;
     while (async_ret == NOT_DONE) {
Index: qemu/block-qcow.c
===================================================================
--- qemu.orig/block-qcow.c      2009-03-14 18:08:40.000000000 +0100
+++ qemu/block-qcow.c   2009-03-14 18:08:41.000000000 +0100
@@ -525,6 +525,8 @@ static int qcow_write(BlockDriverState *
 typedef struct QCowAIOCB {
     BlockDriverAIOCB common;
     int64_t sector_num;
+    struct iovec *iov;
+    int nr_iov;
     uint8_t *buf;
     int nb_sectors;
     int n;
@@ -542,12 +544,8 @@ static void qcow_aio_read_cb(void *opaqu
     int index_in_cluster;
 
     acb->hd_aiocb = NULL;
-    if (ret < 0) {
-    fail:
-        acb->common.cb(acb->common.opaque, ret);
-        qemu_aio_release(acb);
-        return;
-    }
+    if (ret < 0)
+        goto done;
 
  redo:
     /* post process the read buffer */
@@ -569,9 +567,8 @@ static void qcow_aio_read_cb(void *opaqu
 
     if (acb->nb_sectors == 0) {
         /* request completed */
-        acb->common.cb(acb->common.opaque, 0);
-        qemu_aio_release(acb);
-        return;
+       ret = 0;
+       goto done;
     }
 
     /* prepare next AIO request */
@@ -590,7 +587,7 @@ static void qcow_aio_read_cb(void *opaqu
             acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
                 &acb->hd_iov, 1, acb->n, qcow_aio_read_cb, acb);
             if (acb->hd_aiocb == NULL)
-                goto fail;
+                goto done;
         } else {
             /* Note: in this case, no need to wait */
             memset(acb->buf, 0, 512 * acb->n);
@@ -599,14 +596,14 @@ static void qcow_aio_read_cb(void *opaqu
     } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
         /* add AIO support for compressed blocks ? */
         if (decompress_cluster(s, acb->cluster_offset) < 0)
-            goto fail;
+            goto done;
         memcpy(acb->buf,
                s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
         goto redo;
     } else {
         if ((acb->cluster_offset & 511) != 0) {
             ret = -EIO;
-            goto fail;
+            goto done;
         }
        acb->hd_iov.iov_base = acb->buf;
        acb->hd_iov.iov_len = acb->n * 512;
@@ -614,12 +611,23 @@ static void qcow_aio_read_cb(void *opaqu
                             (acb->cluster_offset >> 9) + index_in_cluster,
                             &acb->hd_iov, 1, acb->n, qcow_aio_read_cb, acb);
         if (acb->hd_aiocb == NULL)
-            goto fail;
+            goto done;
+    }
+
+    return;
+
+done:
+    if (acb->nr_iov > 1) {
+        iovec_from_buffer(acb->iov, acb->nr_iov, acb->buf,
+                          acb->nb_sectors * 512);
+        qemu_vfree(acb->buf);
     }
+    acb->common.cb(acb->common.opaque, ret);
+    qemu_aio_release(acb);
 }
 
-static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     QCowAIOCB *acb;
@@ -629,7 +637,12 @@ static BlockDriverAIOCB *qcow_aio_read(B
         return NULL;
     acb->hd_aiocb = NULL;
     acb->sector_num = sector_num;
-    acb->buf = buf;
+    acb->iov = iov;
+    acb->nr_iov = nr_iov;
+    if (nr_iov > 1)
+        acb->buf = qemu_memalign(512, nb_sectors * 512);
+    else
+        acb->buf = iov->iov_base;
     acb->nb_sectors = nb_sectors;
     acb->n = 0;
     acb->cluster_offset = 0;
@@ -649,12 +662,8 @@ static void qcow_aio_write_cb(void *opaq
 
     acb->hd_aiocb = NULL;
 
-    if (ret < 0) {
-    fail:
-        acb->common.cb(acb->common.opaque, ret);
-        qemu_aio_release(acb);
-        return;
-    }
+    if (ret < 0)
+        goto done;
 
     acb->nb_sectors -= acb->n;
     acb->sector_num += acb->n;
@@ -662,9 +671,8 @@ static void qcow_aio_write_cb(void *opaq
 
     if (acb->nb_sectors == 0) {
         /* request completed */
-        acb->common.cb(acb->common.opaque, 0);
-        qemu_aio_release(acb);
-        return;
+       ret = 0;
+       goto done;
     }
 
     index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
@@ -676,14 +684,14 @@ static void qcow_aio_write_cb(void *opaq
                                         index_in_cluster + acb->n);
     if (!cluster_offset || (cluster_offset & 511) != 0) {
         ret = -EIO;
-        goto fail;
+        goto done;
     }
     if (s->crypt_method) {
         if (!acb->cluster_data) {
             acb->cluster_data = qemu_mallocz(s->cluster_size);
             if (!acb->cluster_data) {
                 ret = -ENOMEM;
-                goto fail;
+                goto done;
             }
         }
         encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
@@ -700,11 +708,18 @@ static void qcow_aio_write_cb(void *opaq
                                     &acb->hd_iov, 1, acb->n,
                                     qcow_aio_write_cb, acb);
     if (acb->hd_aiocb == NULL)
-        goto fail;
+        goto done;
+    return;
+
+done:
+    if (acb->nr_iov > 1)
+        qemu_vfree(acb->buf);
+    acb->common.cb(acb->common.opaque, ret);
+    qemu_aio_release(acb);
 }
 
-static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     BDRVQcowState *s = bs->opaque;
@@ -717,7 +732,13 @@ static BlockDriverAIOCB *qcow_aio_write(
         return NULL;
     acb->hd_aiocb = NULL;
     acb->sector_num = sector_num;
-    acb->buf = (uint8_t *)buf;
+    acb->iov = iov;
+    acb->nr_iov = nr_iov;
+    if (nr_iov > 1) {
+        acb->buf = qemu_memalign(512, nb_sectors * 512);
+        iovec_to_buffer(iov, nr_iov, acb->buf);
+    } else
+        acb->buf = iov->iov_base;
     acb->nb_sectors = nb_sectors;
     acb->n = 0;
 
@@ -905,8 +926,8 @@ BlockDriver bdrv_qcow = {
     .bdrv_is_allocated = qcow_is_allocated,
     .bdrv_set_key      = qcow_set_key,
     .bdrv_make_empty   = qcow_make_empty,
-    .bdrv_aio_read     = qcow_aio_read,
-    .bdrv_aio_write    = qcow_aio_write,
+    .bdrv_aio_readv    = qcow_aio_readv,
+    .bdrv_aio_writev   = qcow_aio_writev,
     .bdrv_aio_cancel   = qcow_aio_cancel,
     .aiocb_size                = sizeof(QCowAIOCB),
     .bdrv_write_compressed = qcow_write_compressed,
Index: qemu/block-qcow2.c
===================================================================
--- qemu.orig/block-qcow2.c     2009-03-14 18:08:40.000000000 +0100
+++ qemu/block-qcow2.c  2009-03-14 18:08:41.000000000 +0100
@@ -1169,6 +1169,8 @@ static int qcow_write(BlockDriverState *
 typedef struct QCowAIOCB {
     BlockDriverAIOCB common;
     int64_t sector_num;
+    struct iovec *iov;
+    int nr_iov;
     uint8_t *buf;
     int nb_sectors;
     int n;
@@ -1211,12 +1213,8 @@ static void qcow_aio_read_cb(void *opaqu
     int index_in_cluster, n1;
 
     acb->hd_aiocb = NULL;
-    if (ret < 0) {
-fail:
-        acb->common.cb(acb->common.opaque, ret);
-        qemu_aio_release(acb);
-        return;
-    }
+    if (ret < 0)
+        goto done;
 
     /* post process the read buffer */
     if (!acb->cluster_offset) {
@@ -1237,9 +1235,8 @@ fail:
 
     if (acb->nb_sectors == 0) {
         /* request completed */
-        acb->common.cb(acb->common.opaque, 0);
-        qemu_aio_release(acb);
-        return;
+       ret = 0;
+       goto done;
     }
 
     /* prepare next AIO request */
@@ -1259,32 +1256,32 @@ fail:
                                     &acb->hd_iov, 1, acb->n,
                                    qcow_aio_read_cb, acb);
                 if (acb->hd_aiocb == NULL)
-                    goto fail;
+                    goto done;
             } else {
                 ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
                 if (ret < 0)
-                    goto fail;
+                    goto done;
             }
         } else {
             /* Note: in this case, no need to wait */
             memset(acb->buf, 0, 512 * acb->n);
             ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
             if (ret < 0)
-                goto fail;
+                goto done;
         }
     } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
         /* add AIO support for compressed blocks ? */
         if (decompress_cluster(s, acb->cluster_offset) < 0)
-            goto fail;
+            goto done;
         memcpy(acb->buf,
                s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
         ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
         if (ret < 0)
-            goto fail;
+            goto done;
     } else {
         if ((acb->cluster_offset & 511) != 0) {
             ret = -EIO;
-            goto fail;
+            goto done;
         }
 
        acb->hd_iov.iov_base = acb->buf;
@@ -1293,13 +1290,23 @@ fail:
                             (acb->cluster_offset >> 9) + index_in_cluster,
                             &acb->hd_iov, 1, acb->n, qcow_aio_read_cb, acb);
         if (acb->hd_aiocb == NULL)
-            goto fail;
+            goto done;
+    }
+
+    return;
+done:
+    if (acb->nr_iov > 1) {
+        iovec_from_buffer(acb->iov, acb->nr_iov, acb->buf,
+                          acb->nb_sectors * 512);
+        qemu_vfree(acb->buf);
     }
+    acb->common.cb(acb->common.opaque, ret);
+    qemu_aio_release(acb);
 }
 
 static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
+        BlockDriverCompletionFunc *cb, void *opaque, int is_write)
 {
     QCowAIOCB *acb;
 
@@ -1308,7 +1315,14 @@ static QCowAIOCB *qcow_aio_setup(BlockDr
         return NULL;
     acb->hd_aiocb = NULL;
     acb->sector_num = sector_num;
-    acb->buf = buf;
+    acb->iov = iov;
+    acb->nr_iov = nr_iov;
+    if (nr_iov > 1) {
+        acb->buf = qemu_memalign(512, nb_sectors * 512);
+       if (is_write)
+            iovec_to_buffer(iov, nr_iov, acb->buf);
+    } else
+        acb->buf = iov->iov_base;
     acb->nb_sectors = nb_sectors;
     acb->n = 0;
     acb->cluster_offset = 0;
@@ -1316,13 +1330,14 @@ static QCowAIOCB *qcow_aio_setup(BlockDr
     return acb;
 }
 
-static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     QCowAIOCB *acb;
 
-    acb = qcow_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
+    acb = qcow_aio_setup(bs, sector_num, iov, nr_iov, nb_sectors,
+                        cb, opaque, 0);
     if (!acb)
         return NULL;
 
@@ -1341,16 +1356,12 @@ static void qcow_aio_write_cb(void *opaq
 
     acb->hd_aiocb = NULL;
 
-    if (ret < 0) {
-    fail:
-        acb->common.cb(acb->common.opaque, ret);
-        qemu_aio_release(acb);
-        return;
-    }
+    if (ret < 0)
+        goto done;
 
     if (alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) {
         free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters);
-        goto fail;
+        goto done;
     }
 
     acb->nb_sectors -= acb->n;
@@ -1359,9 +1370,8 @@ static void qcow_aio_write_cb(void *opaq
 
     if (acb->nb_sectors == 0) {
         /* request completed */
-        acb->common.cb(acb->common.opaque, 0);
-        qemu_aio_release(acb);
-        return;
+       ret = 0;
+       goto done;
     }
 
     index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
@@ -1375,7 +1385,7 @@ static void qcow_aio_write_cb(void *opaq
                                           n_end, &acb->n, &acb->l2meta);
     if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) {
         ret = -EIO;
-        goto fail;
+        goto done;
     }
     if (s->crypt_method) {
         if (!acb->cluster_data) {
@@ -1395,11 +1405,19 @@ static void qcow_aio_write_cb(void *opaq
                                     &acb->hd_iov, 1, acb->n,
                                     qcow_aio_write_cb, acb);
     if (acb->hd_aiocb == NULL)
-        goto fail;
+        goto done;
+
+    return;
+
+done:
+    if (acb->nr_iov > 1)
+        qemu_vfree(acb->buf);
+    acb->common.cb(acb->common.opaque, ret);
+    qemu_aio_release(acb);
 }
 
-static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     BDRVQcowState *s = bs->opaque;
@@ -1407,7 +1425,8 @@ static BlockDriverAIOCB *qcow_aio_write(
 
     s->cluster_cache_offset = -1; /* disable compressed cache */
 
-    acb = qcow_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, 
opaque);
+    acb = qcow_aio_setup(bs, sector_num, iov, nr_iov, nb_sectors,
+                        cb, opaque, 1);
     if (!acb)
         return NULL;
 
@@ -2611,8 +2630,8 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_set_key      = qcow_set_key,
     .bdrv_make_empty   = qcow_make_empty,
 
-    .bdrv_aio_read     = qcow_aio_read,
-    .bdrv_aio_write    = qcow_aio_write,
+    .bdrv_aio_readv    = qcow_aio_readv,
+    .bdrv_aio_writev   = qcow_aio_writev,
     .bdrv_aio_cancel   = qcow_aio_cancel,
     .aiocb_size                = sizeof(QCowAIOCB),
     .bdrv_write_compressed = qcow_write_compressed,
Index: qemu/block-raw-posix.c
===================================================================
--- qemu.orig/block-raw-posix.c 2009-03-14 18:03:55.000000000 +0100
+++ qemu/block-raw-posix.c      2009-03-14 18:08:41.000000000 +0100
@@ -555,8 +555,8 @@ static int posix_aio_init(void)
     return 0;
 }
 
-static RawAIOCB *raw_aio_setup(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+static RawAIOCB *raw_aio_setup(BlockDriverState *bs, int64_t sector_num,
+        struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     BDRVRawState *s = bs->opaque;
@@ -570,24 +570,25 @@ static RawAIOCB *raw_aio_setup(BlockDriv
         return NULL;
     acb->aiocb.aio_fildes = s->fd;
     acb->aiocb.ev_signo = SIGUSR2;
-    acb->aiocb.aio_buf = buf;
-    if (nb_sectors < 0)
-        acb->aiocb.aio_nbytes = -nb_sectors;
-    else
-        acb->aiocb.aio_nbytes = nb_sectors * 512;
+    acb->aiocb.aio_iov = iov;
+    acb->aiocb.aio_niov = nr_iov;
+    acb->aiocb.aio_nbytes = nb_sectors * 512;
     acb->aiocb.aio_offset = sector_num * 512;
+    acb->aiocb.aio_flags = 0;
+
+    /*
+     * If O_DIRECT is used the buffer needs to be aligned on a sector
+     * boundary. Tell the low level code to ensure that in case it's
+     * not done yet.
+     */
+    if (s->aligned_buf)
+        acb->aiocb.aio_flags |= QEMU_AIO_SECTOR_ALIGNED;
+
     acb->next = posix_aio_state->first_aio;
     posix_aio_state->first_aio = acb;
     return acb;
 }
 
-static void raw_aio_em_cb(void* opaque)
-{
-    RawAIOCB *acb = opaque;
-    acb->common.cb(acb->common.opaque, acb->ret);
-    qemu_aio_release(acb);
-}
-
 static void raw_aio_remove(RawAIOCB *acb)
 {
     RawAIOCB **pacb;
@@ -607,28 +608,13 @@ static void raw_aio_remove(RawAIOCB *acb
     }
 }
 
-static BlockDriverAIOCB *raw_aio_read(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *raw_aio_readv(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     RawAIOCB *acb;
 
-    /*
-     * If O_DIRECT is used and the buffer is not aligned fall back
-     * to synchronous IO.
-     */
-    BDRVRawState *s = bs->opaque;
-
-    if (unlikely(s->aligned_buf != NULL && ((uintptr_t) buf % 512))) {
-        QEMUBH *bh;
-        acb = qemu_aio_get(bs, cb, opaque);
-        acb->ret = raw_pread(bs, 512 * sector_num, buf, 512 * nb_sectors);
-        bh = qemu_bh_new(raw_aio_em_cb, acb);
-        qemu_bh_schedule(bh);
-        return &acb->common;
-    }
-
-    acb = raw_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
+    acb = raw_aio_setup(bs, sector_num, iov, nr_iov, nb_sectors, cb, opaque);
     if (!acb)
         return NULL;
     if (qemu_paio_read(&acb->aiocb) < 0) {
@@ -638,28 +624,13 @@ static BlockDriverAIOCB *raw_aio_read(Bl
     return &acb->common;
 }
 
-static BlockDriverAIOCB *raw_aio_write(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     RawAIOCB *acb;
 
-    /*
-     * If O_DIRECT is used and the buffer is not aligned fall back
-     * to synchronous IO.
-     */
-    BDRVRawState *s = bs->opaque;
-
-    if (unlikely(s->aligned_buf != NULL && ((uintptr_t) buf % 512))) {
-        QEMUBH *bh;
-        acb = qemu_aio_get(bs, cb, opaque);
-        acb->ret = raw_pwrite(bs, 512 * sector_num, buf, 512 * nb_sectors);
-        bh = qemu_bh_new(raw_aio_em_cb, acb);
-        qemu_bh_schedule(bh);
-        return &acb->common;
-    }
-
-    acb = raw_aio_setup(bs, sector_num, (uint8_t*)buf, nb_sectors, cb, opaque);
+    acb = raw_aio_setup(bs, sector_num, iov, nr_iov, nb_sectors, cb, opaque);
     if (!acb)
         return NULL;
     if (qemu_paio_write(&acb->aiocb) < 0) {
@@ -821,8 +792,8 @@ BlockDriver bdrv_raw = {
     .bdrv_flush                = raw_flush,
 
 #ifdef CONFIG_AIO
-    .bdrv_aio_read     = raw_aio_read,
-    .bdrv_aio_write    = raw_aio_write,
+    .bdrv_aio_readv    = raw_aio_readv,
+    .bdrv_aio_writev   = raw_aio_writev,
     .bdrv_aio_cancel   = raw_aio_cancel,
     .aiocb_size                = sizeof(RawAIOCB),
 #endif
@@ -1173,6 +1144,7 @@ static int raw_sg_recv_response(BlockDri
     return raw_pread(bs, -1, buf, count);
 }
 
+#if 0
 static BlockDriverAIOCB *raw_sg_aio_read(BlockDriverState *bs,
                                          void *buf, int count,
                                          BlockDriverCompletionFunc *cb,
@@ -1188,6 +1160,7 @@ static BlockDriverAIOCB *raw_sg_aio_writ
 {
     return raw_aio_write(bs, 0, buf, -(int64_t)count, cb, opaque);
 }
+#endif
 
 BlockDriver bdrv_host_device = {
     .format_name       = "host_device",
@@ -1197,8 +1170,8 @@ BlockDriver bdrv_host_device = {
     .bdrv_flush                = raw_flush,
 
 #ifdef CONFIG_AIO
-    .bdrv_aio_read     = raw_aio_read,
-    .bdrv_aio_write    = raw_aio_write,
+    .bdrv_aio_readv    = raw_aio_readv,
+    .bdrv_aio_writev   = raw_aio_writev,
     .bdrv_aio_cancel   = raw_aio_cancel,
     .aiocb_size                = sizeof(RawAIOCB),
 #endif
@@ -1216,6 +1189,8 @@ BlockDriver bdrv_host_device = {
     .bdrv_ioctl                = raw_ioctl,
     .bdrv_sg_send_command  = raw_sg_send_command,
     .bdrv_sg_recv_response = raw_sg_recv_response,
+#if 0
     .bdrv_sg_aio_read      = raw_sg_aio_read,
     .bdrv_sg_aio_write     = raw_sg_aio_write,
+#endif
 };
Index: qemu/block-raw-win32.c
===================================================================
--- qemu.orig/block-raw-win32.c 2009-03-14 18:03:55.000000000 +0100
+++ qemu/block-raw-win32.c      2009-03-14 18:08:41.000000000 +0100
@@ -44,6 +44,10 @@ typedef struct RawAIOCB {
     BlockDriverAIOCB common;
     HANDLE hEvent;
     OVERLAPPED ov;
+    struct iovec *iov;
+    int nr_iov;
+    char *buf;
+    int is_write;
     int count;
 } RawAIOCB;
 
@@ -188,6 +192,13 @@ static void raw_aio_cb(void *opaque)
     int ret;
 
     ret = GetOverlappedResult(s->hfile, &acb->ov, &ret_count, TRUE);
+
+    if (acb->nr_iov > 1) {
+        if (is_write)
+            iovec_from_buffer(acb->iov, acb->nr_iov, acb->buf, acb->count);
+        qemu_vfree(acb->buf);
+    }
+
     if (!ret || ret_count != acb->count) {
         acb->common.cb(acb->common.opaque, -EIO);
     } else {
@@ -196,7 +207,7 @@ static void raw_aio_cb(void *opaque)
 }
 
 static RawAIOCB *raw_aio_setup(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+        int64_t sector_num, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     RawAIOCB *acb;
@@ -220,44 +231,63 @@ static RawAIOCB *raw_aio_setup(BlockDriv
     return acb;
 }
 
-static BlockDriverAIOCB *raw_aio_read(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *raw_aio_readv(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     BDRVRawState *s = bs->opaque;
     RawAIOCB *acb;
     int ret;
 
-    acb = raw_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
+    acb = raw_aio_setup(bs, sector_num, nb_sectors, cb, opaque);
     if (!acb)
         return NULL;
-    ret = ReadFile(s->hfile, buf, acb->count, NULL, &acb->ov);
+
+    acb->is_write = 0;
+    acb->iov = iov;
+    acb->nr_iov = nr_iov;
+    if (nr_iov > 1)
+        acb->buf = qemu_memalign(512, acb->count);
+    else
+        acb->buf = iov->iov_base;
+
+    ret = ReadFile(s->hfile, acb->buf, acb->count, NULL, &acb->ov);
     if (!ret) {
         qemu_aio_release(acb);
         return NULL;
     }
     qemu_aio_release(acb);
-    return (BlockDriverAIOCB *)acb;
+    return &acb->common;
 }
 
-static BlockDriverAIOCB *raw_aio_write(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque)
 {
     BDRVRawState *s = bs->opaque;
     RawAIOCB *acb;
     int ret;
 
-    acb = raw_aio_setup(bs, sector_num, buf, nb_sectors, cb, opaque);
+    acb = raw_aio_setup(bs, sector_num, nb_sectors, cb, opaque);
     if (!acb)
         return NULL;
+
+    acb->is_write = 1;
+    acb->iov = iov;
+    acb->nr_iov = nr_iov;
+    if (nr_iov > 1) {
+        acb->buf = qemu_memalign(512, acb->count);
+        iovec_to_buffer(iov, nr_iov, acb->buf);
+    } else
+        acb->buf = iov->iov_base;
+
     ret = WriteFile(s->hfile, buf, acb->count, NULL, &acb->ov);
     if (!ret) {
         qemu_aio_release(acb);
         return NULL;
     }
     qemu_aio_release(acb);
-    return (BlockDriverAIOCB *)acb;
+    return &acb->common;
 }
 
 static void raw_aio_cancel(BlockDriverAIOCB *blockacb)
@@ -359,8 +389,8 @@ BlockDriver bdrv_raw = {
     .bdrv_flush                = raw_flush,
 
 #ifdef WIN32_AIO
-    .bdrv_aio_read     = raw_aio_read,
-    .bdrv_aio_write    = raw_aio_write,
+    .bdrv_aio_readv    = raw_aio_readv,
+    .bdrv_aio_writev   = raw_aio_writev,
     .bdrv_aio_cancel   = raw_aio_cancel,
     .aiocb_size                = sizeof(RawAIOCB);
 #endif
@@ -508,8 +538,8 @@ BlockDriver bdrv_host_device = {
     .bdrv_flush                = raw_flush,
 
 #ifdef WIN32_AIO
-    .bdrv_aio_read     = raw_aio_read,
-    .bdrv_aio_write    = raw_aio_write,
+    .bdrv_aio_readv    = raw_aio_readv,
+    .bdrv_aio_writev   = raw_aio_writev,
     .bdrv_aio_cancel   = raw_aio_cancel,
     .aiocb_size                = sizeof(RawAIOCB);
 #endif
Index: qemu/block_int.h
===================================================================
--- qemu.orig/block_int.h       2009-03-14 18:03:55.000000000 +0100
+++ qemu/block_int.h    2009-03-14 18:08:41.000000000 +0100
@@ -48,11 +48,11 @@ struct BlockDriver {
     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
     int (*bdrv_make_empty)(BlockDriverState *bs);
     /* aio */
-    BlockDriverAIOCB *(*bdrv_aio_read)(BlockDriverState *bs,
-        int64_t sector_num, uint8_t *buf, int nb_sectors,
+    BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);
-    BlockDriverAIOCB *(*bdrv_aio_write)(BlockDriverState *bs,
-        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+    BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
+        int64_t sector_num, struct iovec *iov, int nr_iov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);
     void (*bdrv_aio_cancel)(BlockDriverAIOCB *acb);
     int aiocb_size;
Index: qemu/posix-aio-compat.c
===================================================================
--- qemu.orig/posix-aio-compat.c        2009-03-14 18:03:55.000000000 +0100
+++ qemu/posix-aio-compat.c     2009-03-14 18:11:25.000000000 +0100
@@ -21,6 +21,7 @@
 #include "osdep.h"
 
 #include "posix-aio-compat.h"
+#include "qemu-common.h"
 
 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
 static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
@@ -75,6 +76,85 @@ static void thread_create(pthread_t *thr
     if (ret) die2(ret, "pthread_create");
 }
 
+/*
+ * Check if we need to copy the data in the aiocb into a new
+ * properly aligned buffer.
+ */
+static int aiocb_needs_copy(struct qemu_paiocb *aiocb)
+{
+    if (aiocb->aio_flags & QEMU_AIO_SECTOR_ALIGNED) {
+        int i;
+
+        for (i = 0; i < aiocb->aio_niov; i++)
+            if ((uintptr_t) aiocb->aio_iov[i].iov_base % 512)
+                return 1;
+    }
+
+    return 0;
+}
+
+static size_t handle_aiocb_linear(struct qemu_paiocb *aiocb, char *buf)
+{
+    size_t offset = 0;
+    size_t len;
+
+    while (offset < aiocb->aio_nbytes) {
+         if (aiocb->is_write)
+             len = pwrite(aiocb->aio_fildes,
+                          (const char *)buf + offset,
+                          aiocb->aio_nbytes - offset,
+                          aiocb->aio_offset + offset);
+         else
+             len = pread(aiocb->aio_fildes,
+                         buf + offset,
+                         aiocb->aio_nbytes - offset,
+                         aiocb->aio_offset + offset);
+
+         if (len == -1 && errno == EINTR)
+             continue;
+         else if (len == -1) {
+             offset = -errno;
+             break;
+         } else if (len == 0)
+             break;
+
+         offset += len;
+    }
+
+    return offset;
+}
+
+static size_t handle_aiocb(struct qemu_paiocb *aiocb)
+{
+    size_t nbytes;
+    char *buf;
+
+    if (!aiocb_needs_copy(aiocb) && aiocb->aio_niov == 1) {
+        /*
+         * If there is just a single buffer, and it is properly aligned
+         * we can just use plain pread/pwrite without any problems.
+         */
+        return handle_aiocb_linear(aiocb, aiocb->aio_iov->iov_base);
+    }
+
+    /*
+     * Ok, we have to do it the hard way, copy all segments into
+     * a single aligned buffer.
+     */
+    buf = qemu_memalign(512, aiocb->aio_nbytes);
+    if (aiocb->is_write)
+        iovec_to_buffer(aiocb->aio_iov, aiocb->aio_niov, buf);
+
+    nbytes = handle_aiocb_linear(aiocb, buf);
+    if (!aiocb->is_write) {
+       iovec_from_buffer(aiocb->aio_iov, aiocb->aio_niov,
+                          buf, aiocb->aio_nbytes);
+    }
+    qemu_vfree(buf);
+
+    return nbytes;
+}
+
 static void *aio_thread(void *unused)
 {
     pid_t pid;
@@ -88,7 +168,7 @@ static void *aio_thread(void *unused)
 
     while (1) {
         struct qemu_paiocb *aiocb;
-        size_t offset;
+        size_t nbytes;
         int ret = 0;
         qemu_timeval tv;
         struct timespec ts;
@@ -110,39 +190,14 @@ static void *aio_thread(void *unused)
         aiocb = TAILQ_FIRST(&request_list);
         TAILQ_REMOVE(&request_list, aiocb, node);
 
-        offset = 0;
         aiocb->active = 1;
-
         idle_threads--;
-        mutex_unlock(&lock);
-
-        while (offset < aiocb->aio_nbytes) {
-            ssize_t len;
-
-            if (aiocb->is_write)
-                len = pwrite(aiocb->aio_fildes,
-                             (const char *)aiocb->aio_buf + offset,
-                             aiocb->aio_nbytes - offset,
-                             aiocb->aio_offset + offset);
-            else
-                len = pread(aiocb->aio_fildes,
-                            (char *)aiocb->aio_buf + offset,
-                            aiocb->aio_nbytes - offset,
-                            aiocb->aio_offset + offset);
-
-            if (len == -1 && errno == EINTR)
-                continue;
-            else if (len == -1) {
-                offset = -errno;
-                break;
-            } else if (len == 0)
-                break;
-
-            offset += len;
-        }
 
+        mutex_unlock(&lock);
+        nbytes = handle_aiocb(aiocb);
         mutex_lock(&lock);
-        aiocb->ret = offset;
+
+        aiocb->ret = nbytes;
         idle_threads++;
         mutex_unlock(&lock);
 
Index: qemu/posix-aio-compat.h
===================================================================
--- qemu.orig/posix-aio-compat.h        2009-03-14 18:03:55.000000000 +0100
+++ qemu/posix-aio-compat.h     2009-03-14 18:08:41.000000000 +0100
@@ -24,13 +24,18 @@
 #define QEMU_PAIO_NOTCANCELED  0x02
 #define QEMU_PAIO_ALLDONE      0x03
 
+
 struct qemu_paiocb
 {
     int aio_fildes;
-    void *aio_buf;
+    struct iovec *aio_iov;
+    int aio_niov;
     size_t aio_nbytes;
     int ev_signo;
     off_t aio_offset;
+    unsigned aio_flags;
+/* 512 byte alignment required for buffer, offset and length */
+#define QEMU_AIO_SECTOR_ALIGNED        0x01
 
     /* private */
     TAILQ_ENTRY(qemu_paiocb) node;




reply via email to

[Prev in Thread] Current Thread [Next in Thread]