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[PATCH 08/40] igb: Always copy ethernet header
From: |
Akihiko Odaki |
Subject: |
[PATCH 08/40] igb: Always copy ethernet header |
Date: |
Fri, 14 Apr 2023 20:37:05 +0900 |
igb_receive_internal() used to check the iov length to determine
copy the iovs to a contiguous buffer, but the check is flawed in two
ways:
- It does not ensure that iovcnt > 0.
- It does not take virtio-net header into consideration.
The size of this copy is just 22 octets, which can be even less than
the code size required for checks. This (wrong) optimization is probably
not worth so just remove it. Removing this also allows igb to assume
aligned accesses for the ethernet header.
Fixes: 3a977deebe ("Intrdocue igb device emulation")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
hw/net/igb_core.c | 39 +++++++++++++++++++++------------------
1 file changed, 21 insertions(+), 18 deletions(-)
diff --git a/hw/net/igb_core.c b/hw/net/igb_core.c
index 53f60fc3d3..1d188b526c 100644
--- a/hw/net/igb_core.c
+++ b/hw/net/igb_core.c
@@ -67,6 +67,11 @@ typedef struct IGBTxPktVmdqCallbackContext {
NetClientState *nc;
} IGBTxPktVmdqCallbackContext;
+typedef struct L2Header {
+ struct eth_header eth;
+ struct vlan_header vlan[2];
+} L2Header;
+
static ssize_t
igb_receive_internal(IGBCore *core, const struct iovec *iov, int iovcnt,
bool has_vnet, bool *external_tx);
@@ -961,15 +966,16 @@ igb_rx_is_oversized(IGBCore *core, uint16_t qn, size_t
size)
return size > (lpe ? max_ethernet_lpe_size : max_ethernet_vlan_size);
}
-static uint16_t igb_receive_assign(IGBCore *core, const struct eth_header
*ehdr,
+static uint16_t igb_receive_assign(IGBCore *core, const L2Header *l2_header,
size_t size, E1000E_RSSInfo *rss_info,
bool *external_tx)
{
static const int ta_shift[] = { 4, 3, 2, 0 };
+ const struct eth_header *ehdr = &l2_header->eth;
uint32_t f, ra[2], *macp, rctl = core->mac[RCTL];
uint16_t queues = 0;
uint16_t oversized = 0;
- uint16_t vid = lduw_be_p(&PKT_GET_VLAN_HDR(ehdr)->h_tci) & VLAN_VID_MASK;
+ uint16_t vid = be16_to_cpu(l2_header->vlan[0].h_tci) & VLAN_VID_MASK;
bool accepted = false;
int i;
@@ -1590,14 +1596,13 @@ static ssize_t
igb_receive_internal(IGBCore *core, const struct iovec *iov, int iovcnt,
bool has_vnet, bool *external_tx)
{
- static const int maximum_ethernet_hdr_len = (ETH_HLEN + 8);
-
uint16_t queues = 0;
uint32_t n = 0;
- uint8_t min_buf[ETH_ZLEN];
+ union {
+ L2Header l2_header;
+ uint8_t octets[ETH_ZLEN];
+ } min_buf;
struct iovec min_iov;
- struct eth_header *ehdr;
- uint8_t *filter_buf;
size_t size, orig_size;
size_t iov_ofs = 0;
E1000E_RxRing rxr;
@@ -1623,24 +1628,21 @@ igb_receive_internal(IGBCore *core, const struct iovec
*iov, int iovcnt,
net_rx_pkt_unset_vhdr(core->rx_pkt);
}
- filter_buf = iov->iov_base + iov_ofs;
orig_size = iov_size(iov, iovcnt);
size = orig_size - iov_ofs;
/* Pad to minimum Ethernet frame length */
if (size < sizeof(min_buf)) {
- iov_to_buf(iov, iovcnt, iov_ofs, min_buf, size);
- memset(&min_buf[size], 0, sizeof(min_buf) - size);
+ iov_to_buf(iov, iovcnt, iov_ofs, &min_buf, size);
+ memset(&min_buf.octets[size], 0, sizeof(min_buf) - size);
e1000x_inc_reg_if_not_full(core->mac, RUC);
- min_iov.iov_base = filter_buf = min_buf;
+ min_iov.iov_base = &min_buf;
min_iov.iov_len = size = sizeof(min_buf);
iovcnt = 1;
iov = &min_iov;
iov_ofs = 0;
- } else if (iov->iov_len < maximum_ethernet_hdr_len) {
- /* This is very unlikely, but may happen. */
- iov_to_buf(iov, iovcnt, iov_ofs, min_buf, maximum_ethernet_hdr_len);
- filter_buf = min_buf;
+ } else {
+ iov_to_buf(iov, iovcnt, iov_ofs, &min_buf, sizeof(min_buf.l2_header));
}
/* Discard oversized packets if !LPE and !SBP. */
@@ -1648,11 +1650,12 @@ igb_receive_internal(IGBCore *core, const struct iovec
*iov, int iovcnt,
return orig_size;
}
- ehdr = PKT_GET_ETH_HDR(filter_buf);
- net_rx_pkt_set_packet_type(core->rx_pkt, get_eth_packet_type(ehdr));
+ net_rx_pkt_set_packet_type(core->rx_pkt,
+ get_eth_packet_type(&min_buf.l2_header.eth));
net_rx_pkt_set_protocols(core->rx_pkt, iov, iovcnt, iov_ofs);
- queues = igb_receive_assign(core, ehdr, size, &rss_info, external_tx);
+ queues = igb_receive_assign(core, &min_buf.l2_header, size,
+ &rss_info, external_tx);
if (!queues) {
trace_e1000e_rx_flt_dropped();
return orig_size;
--
2.40.0
- Re: [PATCH 04/40] igb: Include the second VLAN tag in the buffer, (continued)
[PATCH 03/40] igb: Fix Rx packet type encoding, Akihiko Odaki, 2023/04/14
[PATCH 05/40] igb: Do not require CTRL.VME for tx VLAN tagging, Akihiko Odaki, 2023/04/14
[PATCH 06/40] net/net_rx_pkt: Use iovec for net_rx_pkt_set_protocols(), Akihiko Odaki, 2023/04/14
[PATCH 07/40] e1000e: Always copy ethernet header, Akihiko Odaki, 2023/04/14
[PATCH 08/40] igb: Always copy ethernet header,
Akihiko Odaki <=
[PATCH 09/40] Fix references to igb Avocado test, Akihiko Odaki, 2023/04/14
[PATCH 11/40] tests/avocado: Remove test_igb_nomsi_kvm, Akihiko Odaki, 2023/04/14
[PATCH 10/40] tests/avocado: Remove unused imports, Akihiko Odaki, 2023/04/14
[PATCH 12/40] hw/net/net_tx_pkt: Remove net_rx_pkt_get_l4_info, Akihiko Odaki, 2023/04/14
[PATCH 13/40] net/eth: Rename eth_setup_vlan_headers_ex, Akihiko Odaki, 2023/04/14
[PATCH 14/40] e1000x: Share more Rx filtering logic, Akihiko Odaki, 2023/04/14