From 6476804e3cd2e1da23dee03024a21ab0e5c1f8ec Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Wed, 18 Dec 2013 19:57:46 +0000
Subject: [PATCH] OvmfPkg: VirtioBlkInit(): expose virtio-blk topology in
 BlockIo

UEFI spec                                virtio spec
=======================================  =================================
LowestAlignedLba EFI_LBA (UINT64)        alignment_offset u8
+--------------------------------------  +--------------------------------
| first LBA that is aligned to a         | offset of first aligned
| physical block boundary (SCSI          | logical block
| definition)

LogicalBlocksPerPhysicalBlock UINT32     physical_block_exp u8
+--------------------------------------  +--------------------------------
| number of logical blocks per           | # of logical blocks per
| physical block [...] does not contain  | physical block (log2)
| an exponential value

OptimalTransferLengthGranularity UINT32  opt_io_size le32
+--------------------------------------  +--------------------------------
| optimal transfer length granularity    | optimal (suggested maximum) I/O
| as a number of logical blocks [...] A  | size in blocks
| value of 0 means there is no reported
| optimal transfer length granularity

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15004 6f19259b-4bc3-4df7-8a09-765794883524
---
 OvmfPkg/VirtioBlkDxe/VirtioBlk.c | 42 +++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
index 5815cdf375..55184faab2 100644
--- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
+++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
@@ -595,8 +595,15 @@ VirtioBlkInit (
   UINT32     Features;
   UINT64     NumSectors;
   UINT32     BlockSize;
+  UINT8      PhysicalBlockExp;
+  UINT8      AlignmentOffset;
+  UINT32     OptIoSize;
   UINT16     QueueSize;
 
+  PhysicalBlockExp = 0;
+  AlignmentOffset = 0;
+  OptIoSize = 0;
+
   //
   // Execute virtio-0.9.5, 2.2.1 Device Initialization Sequence.
   //
@@ -662,6 +669,28 @@ VirtioBlkInit (
     BlockSize = 512;
   }
 
+  if (Features & VIRTIO_BLK_F_TOPOLOGY) {
+    Status = VIRTIO_CFG_READ (Dev, Topology.PhysicalBlockExp,
+               &PhysicalBlockExp);
+    if (EFI_ERROR (Status)) {
+      goto Failed;
+    }
+    if (PhysicalBlockExp >= 32) {
+      Status = EFI_UNSUPPORTED;
+      goto Failed;
+    }
+
+    Status = VIRTIO_CFG_READ (Dev, Topology.AlignmentOffset, &AlignmentOffset);
+    if (EFI_ERROR (Status)) {
+      goto Failed;
+    }
+
+    Status = VIRTIO_CFG_READ (Dev, Topology.OptIoSize, &OptIoSize);
+    if (EFI_ERROR (Status)) {
+      goto Failed;
+    }
+  }
+
   //
   // step 4b -- allocate virtqueue
   //
@@ -728,9 +757,8 @@ VirtioBlkInit (
   }
 
   //
-  // Populate the exported interface's attributes; see UEFI spec v2.3.1 +
-  // Errata C, 12.8 EFI Block I/O Protocol. We stick to the lowest possible
-  // EFI_BLOCK_IO_PROTOCOL revision for now.
+  // Populate the exported interface's attributes; see UEFI spec v2.4, 12.9 EFI
+  // Block I/O Protocol.
   //
   Dev->BlockIo.Revision              = 0;
   Dev->BlockIo.Media                 = &Dev->BlockIoMedia;
@@ -748,6 +776,14 @@ VirtioBlkInit (
   Dev->BlockIoMedia.IoAlign          = 0;
   Dev->BlockIoMedia.LastBlock        = DivU64x32 (NumSectors,
                                          BlockSize / 512) - 1;
+
+  if (Features & VIRTIO_BLK_F_TOPOLOGY) {
+    Dev->BlockIo.Revision = EFI_BLOCK_IO_PROTOCOL_REVISION3;
+
+    Dev->BlockIoMedia.LowestAlignedLba = AlignmentOffset;
+    Dev->BlockIoMedia.LogicalBlocksPerPhysicalBlock = 1u << PhysicalBlockExp;
+    Dev->BlockIoMedia.OptimalTransferLengthGranularity = OptIoSize;
+  }
   return EFI_SUCCESS;
 
 ReleaseQueue: