From e6e48f3e4e46ec72d85cfa663425ec820d438f5b Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Wed, 12 Aug 2015 14:18:40 +0200
Subject: [PATCH 2/2] ide: Check validity of logical block size

Message-id: <1439389120-20473-2-git-send-email-kwolf@redhat.com>
Patchwork-id: 67519
O-Subject: [RHEL-7.2 qemu-kvm PATCH] ide: Check validity of logical block size
Bugzilla: 1134670
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

Our IDE emulation can't handle logical block sizes other than 512. Check
for it.

The original assumption was that other values would silently be ignored
(which is bad enough), but it's not quite true: The physical block size
is exposed in IDENTIFY DEVICE as a multiple of the logical block size.
Setting a logical block size therefore also corrupts the physical block
size (4096/4096 doesn't silently downgrade to 4096/512, but 512/512).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
(cherry picked from commit d20051856cd2fa8f10fed2d2a0b2751de5f7b20d)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/ide/qdev.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/ide/qdev.c b/hw/ide/qdev.c
index 1d84e15..44f36c3 100644
--- a/hw/ide/qdev.c
+++ b/hw/ide/qdev.c
@@ -159,6 +159,11 @@ static int ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind)
         return -1;
     }
 
+    if (dev->conf.logical_block_size != 512) {
+        error_report("logical_block_size must be 512 for IDE");
+        return -1;
+    }
+
     blkconf_serial(&dev->conf, &dev->serial);
     if (kind != IDE_CD
         && blkconf_geometry(&dev->conf, &dev->chs_trans, 65536, 16, 255) < 0) {
-- 
1.8.3.1