[Qemu-devel] [PATCH 3/5] scsi: add topology support

[Christoph Hellwig <hch@lst.de>]

Export the physical block size in the READ CAPACITY (16) command,
and add the new block limits VPD page to export the minimum and
optiomal I/O sizes.

Note that we also need to bump the scsi revision level to SPC-2
as that is the minimum requirement by at least the Linux kernel
to try READ CAPACITY (16) first and look at the block limits VPD
page.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: qemu/hw/scsi-disk.c
===================================================================
--- qemu.orig/hw/scsi-disk.c	2010-01-29 11:07:50.121003760 +0100
+++ qemu/hw/scsi-disk.c	2010-01-29 11:08:32.944025367 +0100
@@ -346,10 +346,11 @@ static int scsi_disk_emulate_inquiry(SCS
         case 0x00: /* Supported page codes, mandatory */
             DPRINTF("Inquiry EVPD[Supported pages] "
                     "buffer size %zd\n", req->cmd.xfer);
-            outbuf[buflen++] = 3;    // number of pages
+            outbuf[buflen++] = 4;    // number of pages
             outbuf[buflen++] = 0x00; // list of supported pages (this page)
             outbuf[buflen++] = 0x80; // unit serial number
             outbuf[buflen++] = 0x83; // device identification
+            outbuf[buflen++] = 0xb0; // block device characteristics
             break;
 
         case 0x80: /* Device serial number, optional */
@@ -391,6 +392,27 @@ static int scsi_disk_emulate_inquiry(SCS
             buflen += id_len;
             break;
         }
+        case 0xb0: /* block device characteristics */
+        {
+            unsigned int min_io_size = bdrv_get_min_io_size(bdrv) >> 9;
+            unsigned int opt_io_size = bdrv_get_opt_io_size(bdrv) >> 9;
+
+            /* required VPD size with unmap support */
+            outbuf[3] = buflen = 0x3c;
+
+            memset(outbuf + 4, 0, buflen - 4);
+
+            /* optimal transfer length granularity */
+            outbuf[6] = (min_io_size >> 8) & 0xff;
+            outbuf[7] = min_io_size & 0xff;
+
+            /* optimal transfer length */
+            outbuf[12] = (opt_io_size >> 24) & 0xff;
+            outbuf[13] = (opt_io_size >> 16) & 0xff;
+            outbuf[14] = (opt_io_size >> 8) & 0xff;
+            outbuf[15] = opt_io_size & 0xff;
+            break;
+        }
         default:
             BADF("Error: unsupported Inquiry (EVPD[%02X]) "
                  "buffer size %zd\n", page_code, req->cmd.xfer);
@@ -437,7 +459,7 @@ static int scsi_disk_emulate_inquiry(SCS
     memcpy(&outbuf[32], s->version ? s->version : QEMU_VERSION, 4);
     /* Identify device as SCSI-3 rev 1.
        Some later commands are also implemented. */
-    outbuf[2] = 3;
+    outbuf[2] = 5;
     outbuf[3] = 2; /* Format 2 */
 
     if (buflen > 36) {
@@ -794,6 +816,8 @@ static int scsi_disk_emulate_command(SCS
             outbuf[9] = 0;
             outbuf[10] = s->cluster_size * 2;
             outbuf[11] = 0;
+            outbuf[12] = 0;
+            outbuf[13] = bdrv_get_physical_block_exp(bdrv);
             /* Protection, exponent and lowest lba field left blank. */
             buflen = req->cmd.xfer;
             break;