[Qemu-devel] [PATCH 09/12] make windows notice media change

[Glauber Costa <glommer@redhat.com>]

From: Gleb Natapov <gleb@redhat.com>

Windows seems to be very stupid about cdrom media change. It polls
cdrom status and if status goes ready->media not present->ready
it assumes that media was changed. If "media not present" step doesn't
happen even if "medium may have changed" was seen it assumes media
haven't changed. Fake "media not present" step.

Filip Navara did a great job debugging this issue in Windows and this is
what he found out:

BINGO! ... The media present notifications were broken ever since
Windows 2000 it seems. The media change is detected properly and it's
passed to ClassSetMediaChangeState function which in turn calls
ClasspInternalSetMediaChangeState. This function is responsible for
changing some internal state of the device object and sending the PnP
events which later result in application notifications. It has this
tiny bit of code (not copied byte for byte):

if (oldMediaState == NewState) {
  // Media is in the same state it was before.
  return;
}

so the end result is that for the case of UNIT NEEDS ATTENTION /
MEDIUM MAY HAVE CHANGED without NOT READY in-between is really broken.
It results in the internal media change counter incremented, so the
media contents are re-read when necessary, instead of relying on the
cache, but the notifications to applications are never sent.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Message-Id:

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 hw/ide.c |   38 +++++++++++++++++++++++++-------------
 1 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/hw/ide.c b/hw/ide.c
index 9b93e7f..654402f 100644
--- a/hw/ide.c
+++ b/hw/ide.c
@@ -418,6 +418,7 @@ typedef struct IDEState {
     /* ATAPI specific */
     uint8_t sense_key;
     uint8_t asc;
+    uint8_t cdrom_changed;
     int packet_transfer_size;
     int elementary_transfer_size;
     int io_buffer_index;
@@ -1640,9 +1641,10 @@ static void ide_atapi_cmd(IDEState *s)
     }
     switch(s->io_buffer[0]) {
     case GPCMD_TEST_UNIT_READY:
-        if (bdrv_is_inserted(s->bs)) {
+        if (bdrv_is_inserted(s->bs) && !s->cdrom_changed) {
             ide_atapi_cmd_ok(s);
         } else {
+            s->cdrom_changed = 0;
             ide_atapi_cmd_error(s, SENSE_NOT_READY,
                                 ASC_MEDIUM_NOT_PRESENT);
         }
@@ -2102,7 +2104,7 @@ static void cdrom_change_cb(void *opaque)
 
     s->sense_key = SENSE_UNIT_ATTENTION;
     s->asc = ASC_MEDIUM_MAY_HAVE_CHANGED;
-
+    s->cdrom_changed = 1;
     ide_set_irq(s);
 }
 
@@ -2870,7 +2872,7 @@ static void ide_save(QEMUFile* f, IDEState *s)
 }
 
 /* load per IDE drive data */
-static void ide_load(QEMUFile* f, IDEState *s)
+static void ide_load(QEMUFile* f, IDEState *s, int version_id)
 {
     s->mult_sectors=qemu_get_be32(f);
     s->identify_set=qemu_get_be32(f);
@@ -2894,6 +2896,13 @@ static void ide_load(QEMUFile* f, IDEState *s)
 
     qemu_get_8s(f, &s->sense_key);
     qemu_get_8s(f, &s->asc);
+    if (version_id == 3) {
+        qemu_get_8s(f, &s->cdrom_changed);
+    } else {
+        if (s->sense_key == SENSE_UNIT_ATTENTION &&
+                       s->asc == ASC_MEDIUM_MAY_HAVE_CHANGED)
+            s->cdrom_changed = 1;
+    }
     /* XXX: if a transfer is pending, we do not save it yet */
 }
 
@@ -3215,7 +3224,7 @@ static int pci_ide_load(QEMUFile* f, void *opaque, int version_id)
     PCIIDEState *d = opaque;
     int ret, i;
 
-    if (version_id != 2)
+    if (version_id != 2 && version_id != 3)
         return -EINVAL;
     ret = pci_device_load(&d->dev, f);
     if (ret < 0)
@@ -3245,7 +3254,7 @@ static int pci_ide_load(QEMUFile* f, void *opaque, int version_id)
 
     /* per IDE drive data */
     for(i = 0; i < 4; i++) {
-        ide_load(f, &d->ide_if[i]);
+        ide_load(f, &d->ide_if[i], version_id);
     }
     return 0;
 }
@@ -3335,7 +3344,7 @@ void pci_cmd646_ide_init(PCIBus *bus, BlockDriverState **hd_table,
     ide_init2(&d->ide_if[0], hd_table[0], hd_table[1], irq[0]);
     ide_init2(&d->ide_if[2], hd_table[2], hd_table[3], irq[1]);
 
-    register_savevm("ide", 0, 2, pci_ide_save, pci_ide_load, d);
+    register_savevm("ide", 0, 3, pci_ide_save, pci_ide_load, d);
     qemu_register_reset(cmd646_reset, d);
     cmd646_reset(d);
 }
@@ -3394,7 +3403,7 @@ void pci_piix3_ide_init(PCIBus *bus, BlockDriverState **hd_table, int devfn,
         if (hd_table[i])
             hd_table[i]->private = &d->dev;
 
-    register_savevm("ide", 0, 2, pci_ide_save, pci_ide_load, d);
+    register_savevm("ide", 0, 3, pci_ide_save, pci_ide_load, d);
 }
 
 /* hd_table must contain 4 block drivers */
@@ -3430,7 +3439,7 @@ void pci_piix4_ide_init(PCIBus *bus, BlockDriverState **hd_table, int devfn,
     ide_init_ioport(&d->ide_if[0], 0x1f0, 0x3f6);
     ide_init_ioport(&d->ide_if[2], 0x170, 0x376);
 
-    register_savevm("ide", 0, 2, pci_ide_save, pci_ide_load, d);
+    register_savevm("ide", 0, 3, pci_ide_save, pci_ide_load, d);
 }
 
 #if defined(TARGET_PPC)
@@ -3718,7 +3727,7 @@ static int pmac_ide_load(QEMUFile *f, void *opaque, int version_id)
     uint8_t drive1_selected;
     unsigned int i;
 
-    if (version_id != 1)
+    if (version_id != 1 && version_id != 3)
         return -EINVAL;
 
     /* per IDE interface data */
@@ -3728,7 +3737,7 @@ static int pmac_ide_load(QEMUFile *f, void *opaque, int version_id)
 
     /* per IDE drive data */
     for(i = 0; i < 2; i++) {
-        ide_load(f, &s[i]);
+        ide_load(f, &s[i], version_id);
     }
     return 0;
 }
@@ -3759,7 +3768,7 @@ int pmac_ide_init (BlockDriverState **hd_table, qemu_irq irq,
 
     pmac_ide_memory = cpu_register_io_memory(0, pmac_ide_read,
                                              pmac_ide_write, d);
-    register_savevm("ide", 0, 1, pmac_ide_save, pmac_ide_load, d);
+    register_savevm("ide", 0, 3, pmac_ide_save, pmac_ide_load, d);
     qemu_register_reset(pmac_ide_reset, d);
     pmac_ide_reset(d);
 
@@ -4152,6 +4161,9 @@ static int md_load(QEMUFile *f, void *opaque, int version_id)
     int i;
     uint8_t drive1_selected;
 
+    if (version_id != 0 && version_id != 3)
+        return -EINVAL;
+
     qemu_get_8s(f, &s->opt);
     qemu_get_8s(f, &s->stat);
     qemu_get_8s(f, &s->pins);
@@ -4165,7 +4177,7 @@ static int md_load(QEMUFile *f, void *opaque, int version_id)
     s->ide->cur_drive = &s->ide[(drive1_selected != 0)];
 
     for (i = 0; i < 2; i ++)
-        ide_load(f, &s->ide[i]);
+        ide_load(f, &s->ide[i], version_id);
 
     return 0;
 }
@@ -4396,7 +4408,7 @@ struct pcmcia_card_s *dscm1xxxx_init(BlockDriverState *bdrv)
     md->ide->mdata_size = METADATA_SIZE;
     md->ide->mdata_storage = (uint8_t *) qemu_mallocz(METADATA_SIZE);
 
-    register_savevm("microdrive", -1, 0, md_save, md_load, md);
+    register_savevm("microdrive", -1, 3, md_save, md_load, md);
 
     return &md->card;
 }
-- 
1.6.2.2