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

1 files changed, 50 insertions, 34 deletions

diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 96c554fe29..e843f712c2 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -55,6 +55,7 @@ typedef struct SCSIDiskReq {
     /* Both sector and sector_count are in terms of qemu 512 byte blocks.  */
     uint64_t sector;
     uint32_t sector_count;
+    uint32_t buflen;
     struct iovec iov;
     QEMUIOVector qiov;
     uint32_t status;
@@ -78,13 +79,15 @@ struct SCSIDiskState
 };
 
 static int scsi_handle_rw_error(SCSIDiskReq *r, int error, int type);
-static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf);
+static int scsi_disk_emulate_command(SCSIDiskReq *r);
 
 static void scsi_free_request(SCSIRequest *req)
 {
     SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
 
-    qemu_vfree(r->iov.iov_base);
+    if (r->iov.iov_base) {
+        qemu_vfree(r->iov.iov_base);
+    }
 }
 
 /* Helper function for command completion with sense.  */
@@ -108,6 +111,19 @@ static void scsi_cancel_io(SCSIRequest *req)
     r->req.aiocb = NULL;
 }
 
+static uint32_t scsi_init_iovec(SCSIDiskReq *r)
+{
+    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
+
+    if (!r->iov.iov_base) {
+        r->buflen = SCSI_DMA_BUF_SIZE;
+        r->iov.iov_base = qemu_blockalign(s->bs, r->buflen);
+    }
+    r->iov.iov_len = MIN(r->sector_count * 512, r->buflen);
+    qemu_iovec_init_external(&r->qiov, &r->iov, 1);
+    return r->qiov.size / 512;
+}
+
 static void scsi_read_complete(void * opaque, int ret)
 {
     SCSIDiskReq *r = (SCSIDiskReq *)opaque;
@@ -125,12 +141,12 @@ static void scsi_read_complete(void * opaque, int ret)
         }
     }
 
-    DPRINTF("Data ready tag=0x%x len=%zd\n", r->req.tag, r->iov.iov_len);
+    DPRINTF("Data ready tag=0x%x len=%zd\n", r->req.tag, r->qiov.size);
 
-    n = r->iov.iov_len / 512;
+    n = r->qiov.size / 512;
     r->sector += n;
     r->sector_count -= n;
-    scsi_req_data(&r->req, r->iov.iov_len);
+    scsi_req_data(&r->req, r->qiov.size);
 }
 
 static void scsi_flush_complete(void * opaque, int ret)
@@ -181,16 +197,10 @@ static void scsi_read_data(SCSIRequest *req)
         return;
     }
 
-    n = r->sector_count;
-    if (n > SCSI_DMA_BUF_SIZE / 512)
-        n = SCSI_DMA_BUF_SIZE / 512;
-
     if (s->tray_open) {
         scsi_read_complete(r, -ENOMEDIUM);
     }
-    r->iov.iov_len = n * 512;
-    qemu_iovec_init_external(&r->qiov, &r->iov, 1);
-
+    n = scsi_init_iovec(r);
     bdrv_acct_start(s->bs, &r->acct, n * BDRV_SECTOR_SIZE, BDRV_ACCT_READ);
     r->req.aiocb = bdrv_aio_readv(s->bs, r->sector, &r->qiov, n,
                               scsi_read_complete, r);
@@ -239,7 +249,6 @@ static void scsi_write_complete(void * opaque, int ret)
 {
     SCSIDiskReq *r = (SCSIDiskReq *)opaque;
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
-    uint32_t len;
     uint32_t n;
 
     if (r->req.aiocb != NULL) {
@@ -253,19 +262,15 @@ static void scsi_write_complete(void * opaque, int ret)
         }
     }
 
-    n = r->iov.iov_len / 512;
+    n = r->qiov.size / 512;
     r->sector += n;
     r->sector_count -= n;
     if (r->sector_count == 0) {
         scsi_req_complete(&r->req, GOOD);
     } else {
-        len = r->sector_count * 512;
-        if (len > SCSI_DMA_BUF_SIZE) {
-            len = SCSI_DMA_BUF_SIZE;
-        }
-        r->iov.iov_len = len;
-        DPRINTF("Write complete tag=0x%x more=%d\n", r->req.tag, len);
-        scsi_req_data(&r->req, len);
+        scsi_init_iovec(r);
+        DPRINTF("Write complete tag=0x%x more=%d\n", r->req.tag, r->qiov.size);
+        scsi_req_data(&r->req, r->qiov.size);
     }
 }
 
@@ -284,21 +289,19 @@ static void scsi_write_data(SCSIRequest *req)
         return;
     }
 
-    n = r->iov.iov_len / 512;
+    n = r->qiov.size / 512;
     if (n) {
         if (s->tray_open) {
             scsi_write_complete(r, -ENOMEDIUM);
         }
-        qemu_iovec_init_external(&r->qiov, &r->iov, 1);
-
         bdrv_acct_start(s->bs, &r->acct, n * BDRV_SECTOR_SIZE, BDRV_ACCT_WRITE);
         r->req.aiocb = bdrv_aio_writev(s->bs, r->sector, &r->qiov, n,
-                                   scsi_write_complete, r);
+                                       scsi_write_complete, r);
         if (r->req.aiocb == NULL) {
             scsi_write_complete(r, -ENOMEM);
         }
     } else {
-        /* Invoke completion routine to fetch data from host.  */
+        /* Called for the first time.  Ask the driver to send us more data.  */
         scsi_write_complete(r, 0);
     }
 }
@@ -329,7 +332,7 @@ static void scsi_dma_restart_bh(void *opaque)
                 scsi_write_data(&r->req);
                 break;
             case SCSI_REQ_STATUS_RETRY_FLUSH:
-                ret = scsi_disk_emulate_command(r, r->iov.iov_base);
+                ret = scsi_disk_emulate_command(r);
                 if (ret == 0) {
                     scsi_req_complete(&r->req, GOOD);
                 }
@@ -844,13 +847,31 @@ static int scsi_disk_emulate_start_stop(SCSIDiskReq *r)
     return 0;
 }
 
-static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf)
+static int scsi_disk_emulate_command(SCSIDiskReq *r)
 {
     SCSIRequest *req = &r->req;
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
     uint64_t nb_sectors;
+    uint8_t *outbuf;
     int buflen = 0;
 
+    if (!r->iov.iov_base) {
+        /*
+         * FIXME: we shouldn't return anything bigger than 4k, but the code
+         * requires the buffer to be as big as req->cmd.xfer in several
+         * places.  So, do not allow CDBs with a very large ALLOCATION
+         * LENGTH.  The real fix would be to modify scsi_read_data and
+         * dma_buf_read, so that they return data beyond the buflen
+         * as all zeros.
+         */
+        if (req->cmd.xfer > 65536) {
+            goto illegal_request;
+        }
+        r->buflen = MAX(4096, req->cmd.xfer);
+        r->iov.iov_base = qemu_blockalign(s->bs, r->buflen);
+    }
+
+    outbuf = r->iov.iov_base;
     switch (req->cmd.buf[0]) {
     case TEST_UNIT_READY:
         if (s->tray_open || !bdrv_is_inserted(s->bs))
@@ -1001,11 +1022,9 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf)
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
     int32_t len;
     uint8_t command;
-    uint8_t *outbuf;
     int rc;
 
     command = buf[0];
-    outbuf = (uint8_t *)r->iov.iov_base;
     DPRINTF("Command: lun=%d tag=0x%x data=0x%02x", req->lun, req->tag, buf[0]);
 
 #ifdef DEBUG_SCSI
@@ -1034,7 +1053,7 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf)
     case GET_CONFIGURATION:
     case SERVICE_ACTION_IN_16:
     case VERIFY_10:
-        rc = scsi_disk_emulate_command(r, outbuf);
+        rc = scsi_disk_emulate_command(r);
         if (rc < 0) {
             return 0;
         }
@@ -1285,11 +1304,8 @@ static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag,
 {
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, d);
     SCSIRequest *req;
-    SCSIDiskReq *r;
 
     req = scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun, hba_private);
-    r = DO_UPCAST(SCSIDiskReq, req, req);
-    r->iov.iov_base = qemu_blockalign(s->bs, SCSI_DMA_BUF_SIZE);
     return req;
 }