[Qemu-devel] [PATCH 13/17] blockdev: Remove IF_* check for read-only blockdev_init

[Kevin Wolf <kwolf@redhat.com>]

IF_NONE allows read-only, which makes forbidding it in this place
for other types pretty much pointless.

Instead, make sure that all devices for which the check would have
errored out check in their init function that they don't get a read-only
BlockDriverState. This catches even cases where IF_NONE and -device is
used.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c                 | 6 ------
 hw/block/m25p80.c          | 5 +++++
 hw/block/xen_disk.c        | 6 ++++++
 hw/sd/milkymist-memcard.c  | 4 ++++
 hw/sd/omap_mmc.c           | 8 ++++++++
 hw/sd/pl181.c              | 4 ++++
 hw/sd/pxa2xx_mmci.c        | 4 ++++
 hw/sd/sd.c                 | 5 +++++
 hw/sd/sdhci.c              | 4 ++++
 hw/sd/ssi-sd.c             | 3 +++
 tests/qemu-iotests/051.out | 5 ++++-
 11 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index bbdae31..ed4ba65 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -529,12 +529,6 @@ static DriveInfo *blockdev_init(QDict *bs_opts,
     if (media == MEDIA_CDROM) {
         /* CDROM is fine for any interface, don't check.  */
         ro = 1;
-    } else if (ro == 1) {
-        if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY &&
-            type != IF_NONE && type != IF_PFLASH) {
-            error_report("read-only not supported by this bus type");
-            goto err;
-        }
     }
 
     bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
index 8c3b7f0..02a1544 100644
--- a/hw/block/m25p80.c
+++ b/hw/block/m25p80.c
@@ -624,6 +624,11 @@ static int m25p80_init(SSISlave *ss)
     if (dinfo && dinfo->bdrv) {
         DB_PRINT_L(0, "Binding to IF_MTD drive\n");
         s->bdrv = dinfo->bdrv;
+        if (bdrv_is_read_only(s->bdrv)) {
+            fprintf(stderr, "Can't use a read-only drive");
+            return 1;
+        }
+
         /* FIXME: Move to late init */
         if (bdrv_read(s->bdrv, 0, s->storage, DIV_ROUND_UP(s->size,
                                                     BDRV_SECTOR_SIZE))) {
diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c
index f35fc59..828c9d9 100644
--- a/hw/block/xen_disk.c
+++ b/hw/block/xen_disk.c
@@ -39,6 +39,7 @@
 #include "hw/xen/xen_backend.h"
 #include "xen_blkif.h"
 #include "sysemu/blockdev.h"
+#include "qemu/error-report.h"
 
 /* ------------------------------------------------------------- */
 
@@ -829,6 +830,11 @@ static int blk_connect(struct XenDevice *xendev)
         /* setup via qemu cmdline -> already setup for us */
         xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n");
         blkdev->bs = blkdev->dinfo->bdrv;
+        if (bdrv_is_read_only(blkdev->bs) && !readonly) {
+            error_report("Unexpected read-only drive");
+            blkdev->bs = NULL;
+            return -1;
+        }
         /* blkdev->bs is not create by us, we get a reference
          * so we can bdrv_unref() unconditionally */
         bdrv_ref(blkdev->bs);
diff --git a/hw/sd/milkymist-memcard.c b/hw/sd/milkymist-memcard.c
index 42613b3..d1168c9 100644
--- a/hw/sd/milkymist-memcard.c
+++ b/hw/sd/milkymist-memcard.c
@@ -255,6 +255,10 @@ static int milkymist_memcard_init(SysBusDevice *dev)
 
     dinfo = drive_get_next(IF_SD);
     s->card = sd_init(dinfo ? dinfo->bdrv : NULL, false);
+    if (s->card == NULL) {
+        return -1;
+    }
+
     s->enabled = dinfo ? bdrv_is_inserted(dinfo->bdrv) : 0;
 
     memory_region_init_io(&s->regs_region, OBJECT(s), &memcard_mmio_ops, s,
diff --git a/hw/sd/omap_mmc.c b/hw/sd/omap_mmc.c
index bf5d1fb..8c6ab2e 100644
--- a/hw/sd/omap_mmc.c
+++ b/hw/sd/omap_mmc.c
@@ -593,6 +593,10 @@ struct omap_mmc_s *omap_mmc_init(hwaddr base,
 
     /* Instantiate the storage */
     s->card = sd_init(bd, false);
+    if (s->card == NULL) {
+        fprintf(stderr, "Failed to initialise SD card\n");
+        exit(1);
+    }
 
     return s;
 }
@@ -618,6 +622,10 @@ struct omap_mmc_s *omap2_mmc_init(struct omap_target_agent_s *ta,
 
     /* Instantiate the storage */
     s->card = sd_init(bd, false);
+    if (s->card == NULL) {
+        fprintf(stderr, "Failed to initialise SD card\n");
+        exit(1);
+    }
 
     s->cdet = qemu_allocate_irqs(omap_mmc_cover_cb, s, 1)[0];
     sd_set_cb(s->card, NULL, s->cdet);
diff --git a/hw/sd/pl181.c b/hw/sd/pl181.c
index 03875bf..c35896d 100644
--- a/hw/sd/pl181.c
+++ b/hw/sd/pl181.c
@@ -491,6 +491,10 @@ static int pl181_init(SysBusDevice *sbd)
     qdev_init_gpio_out(dev, s->cardstatus, 2);
     dinfo = drive_get_next(IF_SD);
     s->card = sd_init(dinfo ? dinfo->bdrv : NULL, false);
+    if (s->card == NULL) {
+        return -1;
+    }
+
     return 0;
 }
 
diff --git a/hw/sd/pxa2xx_mmci.c b/hw/sd/pxa2xx_mmci.c
index 90c955f..d720bc2 100644
--- a/hw/sd/pxa2xx_mmci.c
+++ b/hw/sd/pxa2xx_mmci.c
@@ -539,6 +539,10 @@ PXA2xxMMCIState *pxa2xx_mmci_init(MemoryRegion *sysmem,
 
     /* Instantiate the actual storage */
     s->card = sd_init(bd, false);
+    if (s->card == NULL) {
+        fprintf(stderr, "Failed to initialise SD card\n");
+        exit(1);
+    }
 
     register_savevm(NULL, "pxa2xx_mmci", 0, 0,
                     pxa2xx_mmci_save, pxa2xx_mmci_load, s);
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 346d86f..7380f06 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -494,6 +494,11 @@ SDState *sd_init(BlockDriverState *bs, bool is_spi)
 {
     SDState *sd;
 
+    if (bdrv_is_read_only(bs)) {
+        fprintf(stderr, "sd_init: Cannot use read-only drive\n");
+        return NULL;
+    }
+
     sd = (SDState *) g_malloc0(sizeof(SDState));
     sd->buf = qemu_blockalign(bs, 512);
     sd->spi = is_spi;
diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index 1483e19..87cd1de 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -1166,6 +1166,10 @@ static void sdhci_initfn(Object *obj)
 
     di = drive_get_next(IF_SD);
     s->card = sd_init(di ? di->bdrv : NULL, false);
+    if (s->card == NULL) {
+        fprintf(stderr, "Failed to initialise SD card\n");
+        exit(1);
+    }
     s->eject_cb = qemu_allocate_irqs(sdhci_insert_eject_cb, s, 1)[0];
     s->ro_cb = qemu_allocate_irqs(sdhci_card_readonly_cb, s, 1)[0];
     sd_set_cb(s->card, s->ro_cb, s->eject_cb);
diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
index d47e237..1bb56c4 100644
--- a/hw/sd/ssi-sd.c
+++ b/hw/sd/ssi-sd.c
@@ -246,6 +246,9 @@ static int ssi_sd_init(SSISlave *dev)
     s->mode = SSI_SD_CMD;
     dinfo = drive_get_next(IF_SD);
     s->sd = sd_init(dinfo ? dinfo->bdrv : NULL, true);
+    if (s->sd == NULL) {
+        return -1;
+    }
     register_savevm(&dev->qdev, "ssi_sd", -1, 1, ssi_sd_save, ssi_sd_load, s);
     return 0;
 }
diff --git a/tests/qemu-iotests/051.out b/tests/qemu-iotests/051.out
index 88e8fa7..bee161e 100644
--- a/tests/qemu-iotests/051.out
+++ b/tests/qemu-iotests/051.out
@@ -128,7 +128,10 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) q^[[K^[[Dqu^[[K^[[D^[[Dqui^[[K^[[D^[[D^[[Dquit^[[K
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=ide,readonly=on
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=ide,readonly=on: read-only not supported by this bus type
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) QEMU_PROG: Can't use a read-only drive
+QEMU_PROG: Device initialization failed.
+QEMU_PROG: Initialization of device ide-hd failed
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=virtio,readonly=on
 QEMU X.Y.Z monitor - type 'help' for more information
-- 
1.8.1.4