From 55c6a5611acc88b9c97fff3324fc743fafc6d0c7 Mon Sep 17 00:00:00 2001
From: Michael Contreras <michael@inetric.com>
Date: Sun, 2 Dec 2012 20:11:22 -0800
Subject: [PATCH] e1000: Discard packets that are too long if !SBP and !LPE

The e1000_receive function for the e1000 needs to discard packets longer than
1522 bytes if the SBP and LPE flags are disabled. The linux driver assumes
this behavior and allocates memory based on this assumption.

Signed-off-by: Michael Contreras <michael@inetric.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
(cherry picked from commit b0d9ffcd0251161c7c92f94804dcf599dfa3edeb)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/e1000.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/e1000.c b/hw/e1000.c
index 4d4ac32..b1d8508 100644
--- a/hw/e1000.c
+++ b/hw/e1000.c
@@ -59,6 +59,9 @@ static int debugflags = DBGBIT(TXERR) | DBGBIT(GENERAL);
 #define PNPMMIO_SIZE      0x20000
 #define MIN_BUF_SIZE      60 /* Min. octets in an ethernet frame sans FCS */
 
+/* this is the size past which hardware will drop packets when setting LPE=0 */
+#define MAXIMUM_ETHERNET_VLAN_SIZE 1522
+
 /*
  * HW models:
  *  E1000_DEV_ID_82540EM works with Windows and Linux
@@ -795,6 +798,13 @@ e1000_receive(NetClientState *nc, const uint8_t *buf, size_t size)
         size = sizeof(min_buf);
     }
 
+    /* Discard oversized packets if !LPE and !SBP. */
+    if (size > MAXIMUM_ETHERNET_VLAN_SIZE
+        && !(s->mac_reg[RCTL] & E1000_RCTL_LPE)
+        && !(s->mac_reg[RCTL] & E1000_RCTL_SBP)) {
+        return size;
+    }
+
     if (!receive_filter(s, buf, size))
         return size;
 
-- 
1.8.1
From 2c0331f4f7d241995452b99afaf0aab00493334a Mon Sep 17 00:00:00 2001
From: Michael Contreras <michael@inetric.com>
Date: Wed, 5 Dec 2012 13:31:30 -0500
Subject: [PATCH] e1000: Discard oversized packets based on SBP|LPE

Discard packets longer than 16384 when !SBP to match the hardware behavior.

Signed-off-by: Michael Contreras <michael@inetric.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/e1000.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/hw/e1000.c b/hw/e1000.c
index 92fb00a..8fd1654 100644
--- a/hw/e1000.c
+++ b/hw/e1000.c
@@ -61,6 +61,8 @@ static int debugflags = DBGBIT(TXERR) | DBGBIT(GENERAL);
 
 /* this is the size past which hardware will drop packets when setting LPE=0 */
 #define MAXIMUM_ETHERNET_VLAN_SIZE 1522
+/* this is the size past which hardware will drop packets when setting LPE=1 */
+#define MAXIMUM_ETHERNET_LPE_SIZE 16384
 
 /*
  * HW models:
@@ -809,8 +811,9 @@ e1000_receive(NetClientState *nc, const uint8_t *buf, size_t size)
     }
 
     /* Discard oversized packets if !LPE and !SBP. */
-    if (size > MAXIMUM_ETHERNET_VLAN_SIZE
-        && !(s->mac_reg[RCTL] & E1000_RCTL_LPE)
+    if ((size > MAXIMUM_ETHERNET_LPE_SIZE ||
+        (size > MAXIMUM_ETHERNET_VLAN_SIZE
+        && !(s->mac_reg[RCTL] & E1000_RCTL_LPE)))
         && !(s->mac_reg[RCTL] & E1000_RCTL_SBP)) {
         return size;
     }
-- 
1.8.1