From e299209ce82c2ee7ca71013bea914208eb9d479b Mon Sep 17 00:00:00 2001
From: Michael S. Tsirkin <mst@redhat.com>
Date: Wed, 1 Sep 2010 17:21:40 -0300
Subject: [PATCH 4/7] bz 547276: e1000: secrc support

RH-Author: Michael S. Tsirkin <mst@redhat.com>
Message-id: <20100901172140.GA14191@redhat.com>
Patchwork-id: 11677
O-Subject: [PATCH RHEL5.6] bz 547276: e1000: secrc support
Bugzilla: 547276
RH-Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
RH-Acked-by: Jes Sorensen <Jes.Sorensen@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

Add support for secrc field. Reportedly needed by old RHEL guests.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Upstream commit: 55e8d1ce6b09300cc5f3adcd9a705156d168381d

Note:
This is not a straight backport from upstream because
upstream also has commit b0b900070c7cb29bbefb732ec00397abe5de6d73.
That one is cosmetic though and seems an unnecessary risk for 5.6.
---
 qemu/hw/e1000.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 qemu/hw/e1000.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/qemu/hw/e1000.c b/qemu/hw/e1000.c
index a31db58..30dfb36 100644
--- a/qemu/hw/e1000.c
+++ b/qemu/hw/e1000.c
@@ -331,6 +331,15 @@ is_vlan_txd(uint32_t txd_lower)
     return ((txd_lower & E1000_TXD_CMD_VLE) != 0);
 }
 
+/* FCS aka Ethernet CRC-32. We don't get it from backends and can't
+ * fill it in, just pad descriptor length by 4 bytes unless guest
+ * told us to strip it off the packet. */
+static inline int
+fcs_len(E1000State *s)
+{
+    return (s->mac_reg[RCTL] & E1000_RCTL_SECRC) ? 0 : 4;
+}
+
 static void
 xmit_seg(E1000State *s)
 {
@@ -635,7 +644,7 @@ e1000_receive(void *opaque, const uint8_t *buf, int size)
     }
 
     rdh_start = s->mac_reg[RDH];
-    size += 4; // for the header
+    size += fcs_len(s);
     do {
         if (s->mac_reg[RDH] == s->mac_reg[RDT] && s->check_rxov) {
             set_ics(s, 0, E1000_ICS_RXO);
-- 
1.6.5.5