Merge remote-tracking branch 'remotes/afaerber/tags/qom-devices-for-peter' into staging

[qemu.git] / hw / ide / pci.c

diff --git a/hw/ide/pci.c b/hw/ide/pci.c
index 4afd0cfe8cd4956aa1cb47d0fcf2caab1581cd02..37dbc291dab210df26b259cddf0445df6f7851a4 100644 (file)
--- a/hw/ide/pci.c
+++ b/hw/ide/pci.c
@@ -53,10 +53,14 @@ static void bmdma_start_dma(IDEDMA *dma, IDEState *s,
 }
 
 /**
- * Return the number of bytes successfully prepared.
- * -1 on error.
+ * Prepare an sglist based on available PRDs.
+ * @limit: How many bytes to prepare total.
+ *
+ * Returns the number of bytes prepared, -1 on error.
+ * IDEState.io_buffer_size will contain the number of bytes described
+ * by the PRDs, whether or not we added them to the sglist.
  */
-static int32_t bmdma_prepare_buf(IDEDMA *dma, int is_write)
+static int32_t bmdma_prepare_buf(IDEDMA *dma, int32_t limit)
 {
     BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
     IDEState *s = bmdma_active_if(bm);
@@ -75,7 +79,7 @@ static int32_t bmdma_prepare_buf(IDEDMA *dma, int is_write)
             /* end of table (with a fail safe of one page) */
             if (bm->cur_prd_last ||
                 (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE) {
-                return s->io_buffer_size;
+                return s->sg.size;
             }
             pci_dma_read(pci_dev, bm->cur_addr, &prd, 8);
             bm->cur_addr += 8;
@@ -90,15 +94,15 @@ static int32_t bmdma_prepare_buf(IDEDMA *dma, int is_write)
         }
         l = bm->cur_prd_len;
         if (l > 0) {
-            qemu_sglist_add(&s->sg, bm->cur_prd_addr, l);
-
-            /* Note: We limit the max transfer to be 2GiB.
-             * This should accommodate the largest ATA transaction
-             * for LBA48 (65,536 sectors) and 32K sector sizes. */
-            if (s->sg.size > INT32_MAX) {
-                error_report("IDE: sglist describes more than 2GiB.");
-                break;
+            uint64_t sg_len;
+
+            /* Don't add extra bytes to the SGList; consume any remaining
+             * PRDs from the guest, but ignore them. */
+            sg_len = MIN(limit - s->sg.size, bm->cur_prd_len);
+            if (sg_len) {
+                qemu_sglist_add(&s->sg, bm->cur_prd_addr, sg_len);
             }
+
             bm->cur_prd_addr += l;
             bm->cur_prd_len -= l;
             s->io_buffer_size += l;
@@ -229,6 +233,22 @@ void bmdma_cmd_writeb(BMDMAState *bm, uint32_t val)
     /* Ignore writes to SSBM if it keeps the old value */
     if ((val & BM_CMD_START) != (bm->cmd & BM_CMD_START)) {
         if (!(val & BM_CMD_START)) {
+            /* First invoke the callbacks of all buffered requests
+             * and flag those requests as orphaned. Ideally there
+             * are no unbuffered (Scatter Gather DMA Requests or
+             * write requests) pending and we can avoid to drain. */
+            IDEBufferedRequest *req;
+            IDEState *s = idebus_active_if(bm->bus);
+            QLIST_FOREACH(req, &s->buffered_requests, list) {
+                if (!req->orphaned) {
+#ifdef DEBUG_IDE
+                    printf("%s: invoking cb %p of buffered request %p with"
+                           " -ECANCELED\n", __func__, req->original_cb, req);
+#endif
+                    req->original_cb(req->original_opaque, -ECANCELED);
+                }
+                req->orphaned = true;
+            }
             /*
              * We can't cancel Scatter Gather DMA in the middle of the
              * operation or a partial (not full) DMA transfer would reach
@@ -242,6 +262,9 @@ void bmdma_cmd_writeb(BMDMAState *bm, uint32_t val)
              * aio operation with preadv/pwritev.
              */
             if (bm->bus->dma->aiocb) {
+#ifdef DEBUG_IDE
+                printf("%s: draining all remaining requests", __func__);
+#endif
                 blk_drain_all();
                 assert(bm->bus->dma->aiocb == NULL);
             }