Merge remote-tracking branch 'kwolf/for-anthony' into staging

* kwolf/for-anthony:
  dataplane: handle misaligned virtio-blk requests
  dataplane: extract virtio-blk read/write processing into do_rdwr_cmd()
  block: make qiov_is_aligned() public
  raw-posix: fix bdrv_aio_ioctl
  sheepdog: implement direct write semantics
  block: do not probe zero-sized disks

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

1 files changed, 60 insertions, 11 deletions

diff --git a/hw/dataplane/virtio-blk.c b/hw/dataplane/virtio-blk.c
index 4c4ad8422a..1f7346ea19 100644
--- a/hw/dataplane/virtio-blk.c
+++ b/hw/dataplane/virtio-blk.c
@@ -34,6 +34,8 @@ typedef struct {
     struct iocb iocb;               /* Linux AIO control block */
     QEMUIOVector *inhdr;            /* iovecs for virtio_blk_inhdr */
     unsigned int head;              /* vring descriptor index */
+    struct iovec *bounce_iov;       /* used if guest buffers are unaligned */
+    QEMUIOVector *read_qiov;        /* for read completion /w bounce buffer */
 } VirtIOBlockRequest;
 
 struct VirtIOBlockDataPlane {
@@ -89,6 +91,18 @@ static void complete_request(struct iocb *iocb, ssize_t ret, void *opaque)
 
     trace_virtio_blk_data_plane_complete_request(s, req->head, ret);
 
+    if (req->read_qiov) {
+        assert(req->bounce_iov);
+        qemu_iovec_from_buf(req->read_qiov, 0, req->bounce_iov->iov_base, len);
+        qemu_iovec_destroy(req->read_qiov);
+        g_slice_free(QEMUIOVector, req->read_qiov);
+    }
+
+    if (req->bounce_iov) {
+        qemu_vfree(req->bounce_iov->iov_base);
+        g_slice_free(struct iovec, req->bounce_iov);
+    }
+
     qemu_iovec_from_buf(req->inhdr, 0, &hdr, sizeof(hdr));
     qemu_iovec_destroy(req->inhdr);
     g_slice_free(QEMUIOVector, req->inhdr);
@@ -130,6 +144,48 @@ static void do_get_id_cmd(VirtIOBlockDataPlane *s,
     complete_request_early(s, head, inhdr, VIRTIO_BLK_S_OK);
 }
 
+static int do_rdwr_cmd(VirtIOBlockDataPlane *s, bool read,
+                       struct iovec *iov, unsigned int iov_cnt,
+                       long long offset, unsigned int head,
+                       QEMUIOVector *inhdr)
+{
+    struct iocb *iocb;
+    QEMUIOVector qiov;
+    struct iovec *bounce_iov = NULL;
+    QEMUIOVector *read_qiov = NULL;
+
+    qemu_iovec_init_external(&qiov, iov, iov_cnt);
+    if (!bdrv_qiov_is_aligned(s->blk->conf.bs, &qiov)) {
+        void *bounce_buffer = qemu_blockalign(s->blk->conf.bs, qiov.size);
+
+        if (read) {
+            /* Need to copy back from bounce buffer on completion */
+            read_qiov = g_slice_new(QEMUIOVector);
+            qemu_iovec_init(read_qiov, iov_cnt);
+            qemu_iovec_concat_iov(read_qiov, iov, iov_cnt, 0, qiov.size);
+        } else {
+            qemu_iovec_to_buf(&qiov, 0, bounce_buffer, qiov.size);
+        }
+
+        /* Redirect I/O to aligned bounce buffer */
+        bounce_iov = g_slice_new(struct iovec);
+        bounce_iov->iov_base = bounce_buffer;
+        bounce_iov->iov_len = qiov.size;
+        iov = bounce_iov;
+        iov_cnt = 1;
+    }
+
+    iocb = ioq_rdwr(&s->ioqueue, read, iov, iov_cnt, offset);
+
+    /* Fill in virtio block metadata needed for completion */
+    VirtIOBlockRequest *req = container_of(iocb, VirtIOBlockRequest, iocb);
+    req->head = head;
+    req->inhdr = inhdr;
+    req->bounce_iov = bounce_iov;
+    req->read_qiov = read_qiov;
+    return 0;
+}
+
 static int process_request(IOQueue *ioq, struct iovec iov[],
                            unsigned int out_num, unsigned int in_num,
                            unsigned int head)
@@ -139,7 +195,6 @@ static int process_request(IOQueue *ioq, struct iovec iov[],
     struct virtio_blk_outhdr outhdr;
     QEMUIOVector *inhdr;
     size_t in_size;
-    struct iocb *iocb;
 
     /* Copy in outhdr */
     if (unlikely(iov_to_buf(iov, out_num, 0, &outhdr,
@@ -167,12 +222,12 @@ static int process_request(IOQueue *ioq, struct iovec iov[],
 
     switch (outhdr.type) {
     case VIRTIO_BLK_T_IN:
-        iocb = ioq_rdwr(ioq, true, in_iov, in_num, outhdr.sector * 512);
-        break;
+        do_rdwr_cmd(s, true, in_iov, in_num, outhdr.sector * 512, head, inhdr);
+        return 0;
 
     case VIRTIO_BLK_T_OUT:
-        iocb = ioq_rdwr(ioq, false, iov, out_num, outhdr.sector * 512);
-        break;
+        do_rdwr_cmd(s, false, iov, out_num, outhdr.sector * 512, head, inhdr);
+        return 0;
 
     case VIRTIO_BLK_T_SCSI_CMD:
         /* TODO support SCSI commands */
@@ -198,12 +253,6 @@ static int process_request(IOQueue *ioq, struct iovec iov[],
         g_slice_free(QEMUIOVector, inhdr);
         return -EFAULT;
     }
-
-    /* Fill in virtio block metadata needed for completion */
-    VirtIOBlockRequest *req = container_of(iocb, VirtIOBlockRequest, iocb);
-    req->head = head;
-    req->inhdr = inhdr;
-    return 0;
 }
 
 static void handle_notify(EventHandler *handler)