Merge remote-tracking branch 'remotes/jnsnow/tags/ide-pull-request' into staging

# gpg: Signature made Wed 13 Apr 2016 00:32:22 BST using RSA key ID AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>"

* remotes/jnsnow/tags/ide-pull-request:
  ide: really restart pending and in-flight atapi dma
  ide: restart atapi dma by re-evaluating command packet
  ide: don't lose pending dma state
  xen: Fix IDE unplug

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

6 files changed, 70 insertions, 37 deletions

diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c
index 1fe58ab7fd..2bb606c1c5 100644
--- a/hw/ide/atapi.c
+++ b/hw/ide/atapi.c
@@ -375,15 +375,18 @@ static void ide_atapi_cmd_check_status(IDEState *s)
 }
 /* ATAPI DMA support */
 
-/* XXX: handle read errors */
 static void ide_atapi_cmd_read_dma_cb(void *opaque, int ret)
 {
     IDEState *s = opaque;
     int data_offset, n;
 
     if (ret < 0) {
-        ide_atapi_io_error(s, ret);
-        goto eot;
+        if (ide_handle_rw_error(s, -ret, ide_dma_cmd_to_retry(s->dma_cmd))) {
+            if (s->bus->error_status) {
+                return;
+            }
+            goto eot;
+        }
     }
 
     if (s->io_buffer_size > 0) {
@@ -481,21 +484,16 @@ static void ide_atapi_cmd_read(IDEState *s, int lba, int nb_sectors,
     }
 }
 
-
-/* Called by *_restart_bh when the transfer function points
- * to ide_atapi_cmd
- */
 void ide_atapi_dma_restart(IDEState *s)
 {
     /*
-     * I'm not sure we have enough stored to restart the command
-     * safely, so give the guest an error it should recover from.
-     * I'm assuming most guests will try to recover from something
-     * listed as a medium error on a CD; it seems to work on Linux.
-     * This would be more of a problem if we did any other type of
-     * DMA operation.
+     * At this point we can just re-evaluate the packet command and start over.
+     * The presence of ->dma_cb callback in the pre_save ensures that the packet
+     * command has been completely sent and we can safely restart command.
      */
-    ide_atapi_cmd_error(s, MEDIUM_ERROR, ASC_NO_SEEK_COMPLETE);
+    s->unit = s->bus->retry_unit;
+    s->bus->dma->ops->restart_dma(s->bus->dma);
+    ide_atapi_cmd(s);
 }
 
 static inline uint8_t ide_atapi_set_profile(uint8_t *buf, uint8_t *index,
diff --git a/hw/ide/core.c b/hw/ide/core.c
index 90524d5e16..41e6a2dc45 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -57,7 +57,6 @@ static const int smart_attributes[][12] = {
     { 190,  0x03, 0x00, 0x45, 0x45, 0x1f, 0x00, 0x1f, 0x1f, 0x00, 0x00, 0x32},
 };
 
-static int ide_handle_rw_error(IDEState *s, int error, int op);
 static void ide_dummy_transfer_stop(IDEState *s);
 
 static void padstr(char *str, const char *src, int len)
@@ -773,7 +772,7 @@ void ide_dma_error(IDEState *s)
     ide_set_irq(s->bus);
 }
 
-static int ide_handle_rw_error(IDEState *s, int error, int op)
+int ide_handle_rw_error(IDEState *s, int error, int op)
 {
     bool is_read = (op & IDE_RETRY_READ) != 0;
     BlockErrorAction action = blk_get_error_action(s->blk, is_read, error);
@@ -783,8 +782,10 @@ static int ide_handle_rw_error(IDEState *s, int error, int op)
         s->bus->error_status = op;
     } else if (action == BLOCK_ERROR_ACTION_REPORT) {
         block_acct_failed(blk_get_stats(s->blk), &s->acct);
-        if (op & IDE_RETRY_DMA) {
+        if (IS_IDE_RETRY_DMA(op)) {
             ide_dma_error(s);
+        } else if (IS_IDE_RETRY_ATAPI(op)) {
+            ide_atapi_io_error(s, -error);
         } else {
             ide_rw_error(s);
         }
@@ -804,14 +805,7 @@ static void ide_dma_cb(void *opaque, int ret)
         return;
     }
     if (ret < 0) {
-        int op = IDE_RETRY_DMA;
-
-        if (s->dma_cmd == IDE_DMA_READ)
-            op |= IDE_RETRY_READ;
-        else if (s->dma_cmd == IDE_DMA_TRIM)
-            op |= IDE_RETRY_TRIM;
-
-        if (ide_handle_rw_error(s, -ret, op)) {
+        if (ide_handle_rw_error(s, -ret, ide_dma_cmd_to_retry(s->dma_cmd))) {
             return;
         }
     }
@@ -879,6 +873,8 @@ static void ide_dma_cb(void *opaque, int ret)
                                         ide_issue_trim, ide_dma_cb, s,
                                         DMA_DIRECTION_TO_DEVICE);
         break;
+    default:
+        abort();
     }
     return;
 
@@ -1641,6 +1637,9 @@ static bool cmd_packet(IDEState *s, uint8_t cmd)
 
     s->status = READY_STAT | SEEK_STAT;
     s->atapi_dma = s->feature & 1;
+    if (s->atapi_dma) {
+        s->dma_cmd = IDE_DMA_ATAPI;
+    }
     s->nsector = 1;
     ide_transfer_start(s, s->io_buffer, ATAPI_PACKET_SIZE,
                        ide_atapi_cmd);
@@ -2525,15 +2524,13 @@ static void ide_restart_bh(void *opaque)
         if (s->bus->dma->ops->restart) {
             s->bus->dma->ops->restart(s->bus->dma);
         }
-    }
-
-    if (error_status & IDE_RETRY_DMA) {
+    } else if (IS_IDE_RETRY_DMA(error_status)) {
         if (error_status & IDE_RETRY_TRIM) {
             ide_restart_dma(s, IDE_DMA_TRIM);
         } else {
             ide_restart_dma(s, is_read ? IDE_DMA_READ : IDE_DMA_WRITE);
         }
-    } else if (error_status & IDE_RETRY_PIO) {
+    } else if (IS_IDE_RETRY_PIO(error_status)) {
         if (is_read) {
             ide_sector_read(s);
         } else {
@@ -2541,15 +2538,11 @@ static void ide_restart_bh(void *opaque)
         }
     } else if (error_status & IDE_RETRY_FLUSH) {
         ide_flush_cache(s);
+    } else if (IS_IDE_RETRY_ATAPI(error_status)) {
+        assert(s->end_transfer_func == ide_atapi_cmd);
+        ide_atapi_dma_restart(s);
     } else {
-        /*
-         * We've not got any bits to tell us about ATAPI - but
-         * we do have the end_transfer_func that tells us what
-         * we're trying to do.
-         */
-        if (s->end_transfer_func == ide_atapi_cmd) {
-            ide_atapi_dma_restart(s);
-        }
+        abort();
     }
 }
 
diff --git a/hw/ide/internal.h b/hw/ide/internal.h
index 86bde26551..d2c458f579 100644
--- a/hw/ide/internal.h
+++ b/hw/ide/internal.h
@@ -338,6 +338,7 @@ enum ide_dma_cmd {
     IDE_DMA_READ,
     IDE_DMA_WRITE,
     IDE_DMA_TRIM,
+    IDE_DMA_ATAPI,
 };
 
 #define ide_cmd_is_read(s) \
@@ -506,13 +507,45 @@ struct IDEDevice {
 };
 
 /* These are used for the error_status field of IDEBus */
+#define IDE_RETRY_MASK 0xf8
 #define IDE_RETRY_DMA  0x08
 #define IDE_RETRY_PIO  0x10
+#define IDE_RETRY_ATAPI 0x20 /* reused IDE_RETRY_READ bit */
 #define IDE_RETRY_READ  0x20
 #define IDE_RETRY_FLUSH 0x40
 #define IDE_RETRY_TRIM 0x80
 #define IDE_RETRY_HBA  0x100
 
+#define IS_IDE_RETRY_DMA(_status) \
+    ((_status) & IDE_RETRY_DMA)
+
+#define IS_IDE_RETRY_PIO(_status) \
+    ((_status) & IDE_RETRY_PIO)
+
+/*
+ * The method of the IDE_RETRY_ATAPI determination is to use a previously
+ * impossible bit combination as a new status value.
+ */
+#define IS_IDE_RETRY_ATAPI(_status)   \
+    (((_status) & IDE_RETRY_MASK) == IDE_RETRY_ATAPI)
+
+static inline uint8_t ide_dma_cmd_to_retry(uint8_t dma_cmd)
+{
+    switch (dma_cmd) {
+    case IDE_DMA_READ:
+        return IDE_RETRY_DMA | IDE_RETRY_READ;
+    case IDE_DMA_WRITE:
+        return IDE_RETRY_DMA;
+    case IDE_DMA_TRIM:
+        return IDE_RETRY_DMA | IDE_RETRY_TRIM;
+    case IDE_DMA_ATAPI:
+        return IDE_RETRY_ATAPI;
+    default:
+        break;
+    }
+    return 0;
+}
+
 static inline IDEState *idebus_active_if(IDEBus *bus)
 {
     return bus->ifs + bus->unit;
@@ -597,4 +630,6 @@ void ide_bus_new(IDEBus *idebus, size_t idebus_size, DeviceState *dev,
                  int bus_id, int max_units);
 IDEDevice *ide_create_drive(IDEBus *bus, int unit, DriveInfo *drive);
 
+int ide_handle_rw_error(IDEState *s, int error, int op);
+
 #endif /* HW_IDE_INTERNAL_H */
diff --git a/hw/ide/macio.c b/hw/ide/macio.c
index 1725e5b23f..76256eb8a8 100644
--- a/hw/ide/macio.c
+++ b/hw/ide/macio.c
@@ -346,6 +346,8 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
     case IDE_DMA_TRIM:
         pmac_dma_trim(s->blk, offset, io->len, pmac_ide_transfer_cb, io);
         break;
+    default:
+        abort();
     }
 
     return;
diff --git a/hw/ide/pci.c b/hw/ide/pci.c
index 92ffee7264..8d56a00b1b 100644
--- a/hw/ide/pci.c
+++ b/hw/ide/pci.c
@@ -308,6 +308,10 @@ static void ide_bmdma_pre_save(void *opaque)
     BMDMAState *bm = opaque;
     uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;
 
+    if (!(bm->status & BM_STATUS_DMAING) && bm->dma_cb) {
+        bm->bus->error_status =
+            ide_dma_cmd_to_retry(bmdma_active_if(bm)->dma_cmd);
+    }
     bm->migration_retry_unit = bm->bus->retry_unit;
     bm->migration_retry_sector_num = bm->bus->retry_sector_num;
     bm->migration_retry_nsector = bm->bus->retry_nsector;
diff --git a/hw/ide/piix.c b/hw/ide/piix.c
index 0a4cbcbcbb..6d76ce980b 100644
--- a/hw/ide/piix.c
+++ b/hw/ide/piix.c
@@ -189,6 +189,7 @@ int pci_piix3_xen_ide_unplug(DeviceState *dev)
                 idedev = pci_ide->bus[di->bus].slave;
             }
             idedev->conf.blk = NULL;
+            monitor_remove_blk(blk);
             blk_unref(blk);
         }
     }