[Qemu-devel] [PATCH 1/7] pc-bios/s390-ccw: support all virtio block size

[Jens Freimann <jfrei@linux.vnet.ibm.com>]

From: "Eugene (jno) Dvurechenski" <jno@linux.vnet.ibm.com>

The block size value may be given "as is" OR as a base value and
a shift count (exponent). So, we have to use calculation to get
the proper number in the code.

The main expression reads as
        (blk_cfg.blk_size << blk_cfg.physical_block_exp)

E.g., various combinations between blk_size=1/physical_block_exp=12
and blk_size=4096/physical_block_exp=0 are valid for 4K blocks.

Signed-off-by: Eugene (jno) Dvurechenski <jno@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
---
 pc-bios/s390-ccw/virtio.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index 31b23b0..04977e4 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -275,12 +275,14 @@ void virtio_assume_scsi(void)
 {
     guessed_disk_nature = true;
     blk_cfg.blk_size = 512;
+    blk_cfg.physical_block_exp = 0;
 }
 
 void virtio_assume_eckd(void)
 {
     guessed_disk_nature = true;
     blk_cfg.blk_size = 4096;
+    blk_cfg.physical_block_exp = 0;
 
     /* this must be here to calculate code segment position */
     blk_cfg.geometry.heads = 15;
@@ -290,31 +292,31 @@ void virtio_assume_eckd(void)
 bool virtio_disk_is_scsi(void)
 {
     if (guessed_disk_nature) {
-        return (blk_cfg.blk_size  == 512);
+        return (virtio_get_block_size()  == 512);
     }
     return (blk_cfg.geometry.heads == 255)
         && (blk_cfg.geometry.sectors == 63)
-        && (blk_cfg.blk_size  == 512);
+        && (virtio_get_block_size()  == 512);
 }
 
 bool virtio_disk_is_eckd(void)
 {
     if (guessed_disk_nature) {
-        return (blk_cfg.blk_size  == 4096);
+        return (virtio_get_block_size()  == 4096);
     }
     return (blk_cfg.geometry.heads == 15)
         && (blk_cfg.geometry.sectors == 12)
-        && (blk_cfg.blk_size  == 4096);
+        && (virtio_get_block_size()  == 4096);
 }
 
 bool virtio_ipl_disk_is_valid(void)
 {
-    return blk_cfg.blk_size && (virtio_disk_is_scsi() || virtio_disk_is_eckd());
+    return virtio_disk_is_scsi() || virtio_disk_is_eckd();
 }
 
 int virtio_get_block_size(void)
 {
-    return blk_cfg.blk_size;
+    return blk_cfg.blk_size << blk_cfg.physical_block_exp;
 }
 
 uint16_t virtio_get_cylinders(void)
-- 
1.8.5.5