e1000: multi-buffer packet support

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>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Michael S. Tsirkin 2011-02-15 18:27:48 +02:00 committed by Aurelien Jarno
parent 1c69371006
commit b19487e27e

View File

@ -642,6 +642,9 @@ 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;
size_t total_size;
if (!(s->mac_reg[RCTL] & E1000_RCTL_EN))
return -1;
@ -654,12 +657,6 @@ 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 +669,16 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
}
rdh_start = s->mac_reg[RDH];
desc_offset = 0;
total_size = size + fcs_len(s);
do {
desc_size = total_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;
}
@ -683,10 +688,22 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
desc.special = vlan_special;
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;
if (desc_offset < size) {
size_t copy_size = size - desc_offset;
if (copy_size > s->rxbuf_size) {
copy_size = s->rxbuf_size;
}
cpu_physical_memory_write(le64_to_cpu(desc.buffer_addr),
(void *)(buf + desc_offset + vlan_offset),
copy_size);
}
desc_offset += desc_size;
if (desc_offset >= total_size) {
desc.length = cpu_to_le16(desc_size);
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 +719,7 @@ 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 < total_size);
s->mac_reg[GPRC]++;
s->mac_reg[TPR]++;