BlockConf: Call backend functions to detect geometry and blocksizes

geometry: hd_geometry_guess function autodetects the drive geometry.
This patch adds a block backend call, that probes the backing device
geometry. If the inner driver method is implemented and succeeds
(currently only for DASDs), the blkconf_geometry will pass-through
the backing device geometry. Otherwise will fallback to old logic.

blocksize: This patch initializes blocksize properties to 0.
In order to set the property a blkconf_blocksizes was introduced.
If user didn't set physical or logical blocksize, it will
retrieve its value from a driver (only succeeds for DASD), otherwise
it will set default 512 value.

The blkconf_blocksizes call was added to all users of BlkConf.

Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1424087278-49393-6-git-send-email-tumanova@linux.vnet.ibm.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

8 files changed, 41 insertions, 2 deletions

diff --git a/hw/block/block.c b/hw/block/block.c
index a625773d44..f7243e5b94 100644
--- a/hw/block/block.c
+++ b/hw/block/block.c
@@ -25,6 +25,30 @@ void blkconf_serial(BlockConf *conf, char **serial)
     }
 }
 
+void blkconf_blocksizes(BlockConf *conf)
+{
+    BlockBackend *blk = conf->blk;
+    BlockSizes blocksizes;
+    int backend_ret;
+
+    backend_ret = blk_probe_blocksizes(blk, &blocksizes);
+    /* fill in detected values if they are not defined via qemu command line */
+    if (!conf->physical_block_size) {
+        if (!backend_ret) {
+           conf->physical_block_size = blocksizes.phys;
+        } else {
+            conf->physical_block_size = BDRV_SECTOR_SIZE;
+        }
+    }
+    if (!conf->logical_block_size) {
+        if (!backend_ret) {
+            conf->logical_block_size = blocksizes.log;
+        } else {
+            conf->logical_block_size = BDRV_SECTOR_SIZE;
+        }
+    }
+}
+
 void blkconf_geometry(BlockConf *conf, int *ptrans,
                       unsigned cyls_max, unsigned heads_max, unsigned secs_max,
                       Error **errp)
diff --git a/hw/block/hd-geometry.c b/hw/block/hd-geometry.c
index 6fcf74df44..b187878fac 100644
--- a/hw/block/hd-geometry.c
+++ b/hw/block/hd-geometry.c
@@ -121,8 +121,16 @@ void hd_geometry_guess(BlockBackend *blk,
                        int *ptrans)
 {
     int cylinders, heads, secs, translation;
+    HDGeometry geo;
 
-    if (guess_disk_lchs(blk, &cylinders, &heads, &secs) < 0) {
+    /* Try to probe the backing device geometry, otherwise fallback
+       to the old logic. (as of 12/2014 probing only succeeds on DASDs) */
+    if (blk_probe_geometry(blk, &geo) == 0) {
+        *pcyls = geo.cylinders;
+        *psecs = geo.sectors;
+        *pheads = geo.heads;
+        translation = BIOS_ATA_TRANSLATION_NONE;
+    } else if (guess_disk_lchs(blk, &cylinders, &heads, &secs) < 0) {
         /* no LCHS guess: use a standard physical disk geometry  */
         guess_chs_for_size(blk, pcyls, pheads, psecs);
         translation = hd_bios_chs_auto_trans(*pcyls, *pheads, *psecs);
diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index ce079aefdd..0f3dfb90ea 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -765,6 +765,7 @@ static int nvme_init(PCIDevice *pci_dev)
     if (!n->serial) {
         return -1;
     }
+    blkconf_blocksizes(&n->conf);
 
     pci_conf = pci_dev->config;
     pci_conf[PCI_INTERRUPT_PIN] = 1;
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 3ad5fe44e2..2acfef87eb 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -893,6 +893,7 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
         error_propagate(errp, err);
         return;
     }
+    blkconf_blocksizes(&conf->conf);
 
     virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
                 sizeof(struct virtio_blk_config));
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 2e47f70eb4..ba81709142 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -580,7 +580,8 @@ static void set_blocksize(Object *obj, Visitor *v, void *opaque,
         error_propagate(errp, local_err);
         return;
     }
-    if (value < min || value > max) {
+    /* value of 0 means "unset" */
+    if (value && (value < min || value > max)) {
         error_set(errp, QERR_PROPERTY_VALUE_OUT_OF_RANGE,
                   dev->id?:"", name, (int64_t)value, min, max);
         return;
diff --git a/hw/ide/qdev.c b/hw/ide/qdev.c
index b4103fa009..788b36133c 100644
--- a/hw/ide/qdev.c
+++ b/hw/ide/qdev.c
@@ -163,6 +163,7 @@ static int ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind)
         return -1;
     }
 
+    blkconf_blocksizes(&dev->conf);
     if (dev->conf.logical_block_size != 512) {
         error_report("logical_block_size must be 512 for IDE");
         return -1;
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index f65618d802..2921728be4 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -2251,6 +2251,7 @@ static void scsi_realize(SCSIDevice *dev, Error **errp)
     }
 
     blkconf_serial(&s->qdev.conf, &s->serial);
+    blkconf_blocksizes(&s->qdev.conf);
     if (dev->type == TYPE_DISK) {
         blkconf_geometry(&dev->conf, NULL, 65535, 255, 255, &err);
         if (err) {
@@ -2290,6 +2291,7 @@ static void scsi_realize(SCSIDevice *dev, Error **errp)
 static void scsi_hd_realize(SCSIDevice *dev, Error **errp)
 {
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
+    blkconf_blocksizes(&s->qdev.conf);
     s->qdev.blocksize = s->qdev.conf.logical_block_size;
     s->qdev.type = TYPE_DISK;
     if (!s->product) {
diff --git a/hw/usb/dev-storage.c b/hw/usb/dev-storage.c
index 65d9aa6147..8edc314fab 100644
--- a/hw/usb/dev-storage.c
+++ b/hw/usb/dev-storage.c
@@ -611,6 +611,7 @@ static void usb_msd_realize_storage(USBDevice *dev, Error **errp)
     }
 
     blkconf_serial(&s->conf, &dev->serial);
+    blkconf_blocksizes(&s->conf);
 
     /*
      * Hack alert: this pretends to be a block device, but it's really