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[Qemu-devel] [PATCHv2] e1000: multi-buffer packet support
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PATCHv2] e1000: multi-buffer packet support |
Date: |
Thu, 3 Feb 2011 18:49:10 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
e1000 supports multi-buffer packets larger than rxbuf_size.
This fixes the following (on linux):
- in guest: ifconfig eth1 mtu 16110
- in host: ifconfig tap0 mtu 16110
ping -s 16082 <guest-ip>
Red Hat bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=602205
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
Changes from v1:
removed dead code
hw/e1000.c | 29 +++++++++++++++++++----------
1 files changed, 19 insertions(+), 10 deletions(-)
diff --git a/hw/e1000.c b/hw/e1000.c
index af101bd..3427ff3 100644
--- a/hw/e1000.c
+++ b/hw/e1000.c
@@ -642,6 +642,8 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf,
size_t size)
uint16_t vlan_special = 0;
uint8_t vlan_status = 0, vlan_offset = 0;
uint8_t min_buf[MIN_BUF_SIZE];
+ size_t desc_offset;
+ size_t desc_size;
if (!(s->mac_reg[RCTL] & E1000_RCTL_EN))
return -1;
@@ -654,12 +656,6 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf,
size_t size)
size = sizeof(min_buf);
}
- if (size > s->rxbuf_size) {
- DBGOUT(RX, "packet too large for buffers (%lu > %d)\n",
- (unsigned long)size, s->rxbuf_size);
- return -1;
- }
-
if (!receive_filter(s, buf, size))
return size;
@@ -672,8 +668,15 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf,
size_t size)
}
rdh_start = s->mac_reg[RDH];
+ desc_offset = 0;
do {
+ desc_size = size - desc_offset;
+ if (desc_size > s->rxbuf_size) {
+ desc_size = s->rxbuf_size;
+ }
if (s->mac_reg[RDH] == s->mac_reg[RDT] && s->check_rxov) {
+ /* Discard all data written so far */
+ s->mac_reg[RDH] = rdh_start;
set_ics(s, 0, E1000_ICS_RXO);
return -1;
}
@@ -684,9 +687,15 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf,
size_t size)
desc.status |= (vlan_status | E1000_RXD_STAT_DD);
if (desc.buffer_addr) {
cpu_physical_memory_write(le64_to_cpu(desc.buffer_addr),
- (void *)(buf + vlan_offset), size);
- desc.length = cpu_to_le16(size + fcs_len(s));
- desc.status |= E1000_RXD_STAT_EOP|E1000_RXD_STAT_IXSM;
+ (void *)(buf + desc_offset +
vlan_offset),
+ desc_size);
+ desc_offset += desc_size;
+ if (desc_offset >= size) {
+ desc.length = cpu_to_le16(desc_size + fcs_len(s));
+ desc.status |= E1000_RXD_STAT_EOP | E1000_RXD_STAT_IXSM;
+ } else {
+ desc.length = cpu_to_le16(desc_size);
+ }
} else { // as per intel docs; skip descriptors with null buf addr
DBGOUT(RX, "Null RX descriptor!!\n");
}
@@ -702,7 +711,7 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf,
size_t size)
set_ics(s, 0, E1000_ICS_RXO);
return -1;
}
- } while (desc.buffer_addr == 0);
+ } while (desc_offset < size);
s->mac_reg[GPRC]++;
s->mac_reg[TPR]++;
--
1.7.3.2.91.g446ac
- [Qemu-devel] [PATCHv2] e1000: multi-buffer packet support,
Michael S. Tsirkin <=