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

* kwolf/for-anthony: (39 commits)
  qemu-iotests: add 036 autoclear feature bit test
  qemu-iotests: add qcow2.py set-feature-bit command
  fdc-test: introduced qtest read_without_media
  fdc: fix implied seek while there is no media in drive
  qcow2: fix autoclear image header update
  xen: Don't peek behind the BlockDriverState abstraction
  xen: Don't change -drive if=xen device name during machine init
  block: Replace bdrv_get_format() by bdrv_get_format_name()
  qemu-img: document qed format on qemu-img man page
  qemu-iotests: COW with many AIO requests on the same cluster
  qemu-iotests: Some backing file COW tests
  qcow2: Fix avail_sectors in cluster allocation code
  qcow2: Simplify calculation for COW area at the end
  qcow2: always operate caches in writeback mode
  ide: support enable/disable write cache
  block: always open drivers in writeback mode
  block: add bdrv_set_enable_write_cache
  block: copy enable_write_cache in bdrv_append
  savevm: flush after saving vm state
  block: flush in writethrough mode after writes
  ...

1 files changed, 18 insertions, 3 deletions

diff --git a/hw/ide/core.c b/hw/ide/core.c
index 9785d5f713..f28229a193 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -1047,6 +1047,7 @@ static bool ide_cmd_permitted(IDEState *s, uint32_t cmd)
 
 void ide_exec_cmd(IDEBus *bus, uint32_t val)
 {
+    uint16_t *identify_data;
     IDEState *s;
     int n;
     int lba48 = 0;
@@ -1231,10 +1232,21 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
             goto abort_cmd;
         /* XXX: valid for CDROM ? */
         switch(s->feature) {
-        case 0xcc: /* reverting to power-on defaults enable */
-        case 0x66: /* reverting to power-on defaults disable */
         case 0x02: /* write cache enable */
+            bdrv_set_enable_write_cache(s->bs, true);
+            identify_data = (uint16_t *)s->identify_data;
+            put_le16(identify_data + 85, (1 << 14) | (1 << 5) | 1);
+            s->status = READY_STAT | SEEK_STAT;
+            ide_set_irq(s->bus);
+            break;
         case 0x82: /* write cache disable */
+            bdrv_set_enable_write_cache(s->bs, false);
+            identify_data = (uint16_t *)s->identify_data;
+            put_le16(identify_data + 85, (1 << 14) | 1);
+            ide_flush_cache(s);
+            break;
+        case 0xcc: /* reverting to power-on defaults enable */
+        case 0x66: /* reverting to power-on defaults disable */
         case 0xaa: /* read look-ahead enable */
         case 0x55: /* read look-ahead disable */
         case 0x05: /* set advanced power management mode */
@@ -1250,7 +1262,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
             break;
         case 0x03: { /* set transfer mode */
 		uint8_t val = s->nsector & 0x07;
-            uint16_t *identify_data = (uint16_t *)s->identify_data;
+		identify_data = (uint16_t *)s->identify_data;
 
 		switch (s->nsector >> 3) {
 		case 0x00: /* pio default */
@@ -2146,6 +2158,9 @@ static int ide_drive_post_load(void *opaque, int version_id)
             s->cdrom_changed = 1;
         }
     }
+    if (s->identify_set) {
+        bdrv_set_enable_write_cache(s->bs, !!(s->identify_data[85] & (1 << 5)));
+    }
     return 0;
 }