PIO read requests on the ATAPI interface used to be sync blk requests.
This has two significant drawbacks. First the main loop hangs util an
I/O request is completed and secondly if the I/O request does not
complete (e.g. due to an unresponsive storage) Qemu hangs completely.
Signed-off-by: Peter Lieven <address@hidden>
---
hw/ide/atapi.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 84 insertions(+), 9 deletions(-)
diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c
index 747f466..2271ea2 100644
--- a/hw/ide/atapi.c
+++ b/hw/ide/atapi.c
@@ -105,11 +105,16 @@ static void cd_data_to_raw(uint8_t *buf, int lba)
memset(buf, 0, 288);
}
-static int cd_read_sector(IDEState *s, int lba, uint8_t *buf, int sector_size)
+static int
+cd_read_sector_sync(IDEState *s, int lba, uint8_t *buf)
{
int ret;
- switch(sector_size) {
+#ifdef DEBUG_IDE_ATAPI
+ printf("cd_read_sector_sync: lba=%d\n", lba);
+#endif
+
+ switch (s->cd_sector_size) {
case 2048:
block_acct_start(blk_get_stats(s->blk), &s->acct,
4 * BDRV_SECTOR_SIZE, BLOCK_ACCT_READ);
@@ -129,9 +134,71 @@ static int cd_read_sector(IDEState *s, int lba, uint8_t
*buf, int sector_size)
ret = -EIO;
break;
}
+
+ if (!ret) {
+ s->lba++;
+ s->io_buffer_index = 0;
+ }
+
return ret;
}
+static void cd_read_sector_cb(void *opaque, int ret)
+{
+ IDEState *s = opaque;
+
+ block_acct_done(blk_get_stats(s->blk), &s->acct);
+
+#ifdef DEBUG_IDE_ATAPI
+ printf("cd_read_sector_cb: lba=%d ret=%d\n", s->lba, ret);
+#endif
+
+ if (ret < 0) {
+ ide_atapi_io_error(s, ret);
+ return;
+ }
+
+ if (s->cd_sector_size == 2352) {
+ cd_data_to_raw(s->io_buffer, s->lba);
+ }
+
+ s->lba++;
+ s->io_buffer_index = 0;
+ s->status &= ~BUSY_STAT;
+
+ ide_atapi_cmd_reply_end(s);
+}
+
+static int cd_read_sector(IDEState *s, int lba, void *buf)
+{
+ if (s->cd_sector_size != 2048 && s->cd_sector_size != 2352) {
+ return -EINVAL;
+ }
+
+ s->iov.iov_base = buf;
+ if (s->cd_sector_size == 2352) {
+ buf += 16;
+ }
+
+ s->iov.iov_len = 4 * BDRV_SECTOR_SIZE;
+ qemu_iovec_init_external(&s->qiov, &s->iov, 1);
+
+#ifdef DEBUG_IDE_ATAPI
+ printf("cd_read_sector: lba=%d\n", lba);
+#endif
+
+ if (blk_aio_readv(s->blk, (int64_t)lba << 2, &s->qiov, 4,
+ cd_read_sector_cb, s) == NULL) {
+ return -EIO;
+ }
+
+ block_acct_start(blk_get_stats(s->blk), &s->acct,
+ 4 * BDRV_SECTOR_SIZE, BLOCK_ACCT_READ);
+
+ s->status |= BUSY_STAT;
+ return 0;
+}
+
void ide_atapi_cmd_ok(IDEState *s)
{
s->error = 0;
@@ -182,18 +249,27 @@ void ide_atapi_cmd_reply_end(IDEState *s)
ide_atapi_cmd_ok(s);
ide_set_irq(s->bus);
#ifdef DEBUG_IDE_ATAPI
- printf("status=0x%x\n", s->status);
+ printf("end of transfer, status=0x%x\n", s->status);
#endif
} else {
/* see if a new sector must be read */
if (s->lba != -1 && s->io_buffer_index >= s->cd_sector_size) {
- ret = cd_read_sector(s, s->lba, s->io_buffer, s->cd_sector_size);
- if (ret < 0) {
- ide_atapi_io_error(s, ret);
+ if (!s->elementary_transfer_size) {
+ ret = cd_read_sector(s, s->lba, s->io_buffer);
+ if (ret < 0) {
+ ide_atapi_io_error(s, ret);
+ }
return;
+ } else {
+ /* rebuffering within an elementary transfer is
+ * only possible with a sync request because we
+ * end up with a race condition otherwise */
+ ret = cd_read_sector_sync(s, s->lba, s->io_buffer);
+ if (ret < 0) {
+ ide_atapi_io_error(s, ret);
+ return;
+ }
}
- s->lba++;
- s->io_buffer_index = 0;
}
if (s->elementary_transfer_size > 0) {
/* there are some data left to transmit in this elementary
@@ -275,7 +351,6 @@ static void ide_atapi_cmd_read_pio(IDEState *s, int lba,
int nb_sectors,
s->io_buffer_index = sector_size;
s->cd_sector_size = sector_size;
- s->status = READY_STAT | SEEK_STAT;
ide_atapi_cmd_reply_end(s);
}