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[Qemu-devel] [PATCH] e1000: fix link down handling with auto negotiation
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PATCH] e1000: fix link down handling with auto negotiation |
Date: |
Tue, 5 Feb 2013 21:00:21 +0200 |
Fixes a couple of regression bugs introduced by
b9d03e352cb6b31a66545763f6a1e20c9abf0c2c and related to
auto-negotiation:
- Auto-negotiation currently sets link up even if it was
forced down from the monitor.
- If Auto-negotiation was in progress during migration,
link will never come up.
As a fix, don't touch NC link_down field at all,
instead add code on receive path to check
guest link status.
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
This was lightly tested only. Intend to test some more
and report, testing results wellcome.
hw/e1000.c | 50 +++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 43 insertions(+), 7 deletions(-)
diff --git a/hw/e1000.c b/hw/e1000.c
index bb150c6..f537974 100644
--- a/hw/e1000.c
+++ b/hw/e1000.c
@@ -166,11 +166,10 @@ static void
set_phy_ctrl(E1000State *s, int index, uint16_t val)
{
if ((val & MII_CR_AUTO_NEG_EN) && (val & MII_CR_RESTART_AUTO_NEG)) {
- qemu_get_queue(s->nic)->link_down = true;
e1000_link_down(s);
s->phy_reg[PHY_STATUS] &= ~MII_SR_AUTONEG_COMPLETE;
DBGOUT(PHY, "Start link auto negotiation\n");
qemu_mod_timer(s->autoneg_timer, qemu_get_clock_ms(vm_clock) + 500);
}
}
@@ -178,8 +182,9 @@ static void
e1000_autoneg_timer(void *opaque)
{
E1000State *s = opaque;
- qemu_get_queue(s->nic)->link_down = false;
- e1000_link_up(s);
+ if (!qemu_get_queue(s->nic)->link_down) {
+ e1000_link_up(s);
+ }
s->phy_reg[PHY_STATUS] |= MII_SR_AUTONEG_COMPLETE;
DBGOUT(PHY, "Auto negotiation is completed\n");
}
@@ -784,7 +790,8 @@ e1000_can_receive(NetClientState *nc)
{
E1000State *s = qemu_get_nic_opaque(nc);
- return (s->mac_reg[RCTL] & E1000_RCTL_EN) && e1000_has_rxbufs(s, 1);
+ return (s->mac_reg[STATUS] & E1000_STATUS_LU) &&
+ (s->mac_reg[RCTL] & E1000_RCTL_EN) && e1000_has_rxbufs(s, 1);
}
static uint64_t rx_desc_base(E1000State *s)
@@ -810,8 +817,13 @@ e1000_receive(NetClientState *nc, const uint8_t *buf,
size_t size)
size_t desc_size;
size_t total_size;
- if (!(s->mac_reg[RCTL] & E1000_RCTL_EN))
+ if (!(s->mac_reg[STATUS] & E1000_STATUS_LU)) {
return -1;
+ }
+
+ if (!(s->mac_reg[RCTL] & E1000_RCTL_EN)) {
+ return -1;
+ }
/* Pad to minimum Ethernet frame length */
if (size < sizeof(min_buf)) {
@@ -1110,14 +1122,37 @@ static bool is_version_1(void *opaque, int version_id)
return version_id == 1;
}
+static void e1000_pre_save(void *opaque)
+{
+ E1000State *s = opaque;
+ NetClientState *nc = qemu_get_queue(s->nic);
+ /*
+ * If link is down and auto-negotiation is ongoing, complete
+ * auto-negotiation immediately. This allows is to look at
+ * MII_SR_AUTONEG_COMPLETE to infer link status on load.
+ */
+ if (nc->link_down &&
+ s->phy_reg[PHY_CTRL] & MII_CR_AUTO_NEG_EN &&
+ s->phy_reg[PHY_CTRL] & MII_CR_RESTART_AUTO_NEG) {
+ s->phy_reg[PHY_STATUS] |= MII_SR_AUTONEG_COMPLETE;
+ }
+}
+
static int e1000_post_load(void *opaque, int version_id)
{
E1000State *s = opaque;
NetClientState *nc = qemu_get_queue(s->nic);
/* nc.link_down can't be migrated, so infer link_down according
- * to link status bit in mac_reg[STATUS] */
+ * to link status bit in mac_reg[STATUS].
+ * Alternatively, restart link negotiation if it was in progress. */
nc->link_down = (s->mac_reg[STATUS] & E1000_STATUS_LU) == 0;
+ if (s->phy_reg[PHY_CTRL] & MII_CR_AUTO_NEG_EN &&
+ s->phy_reg[PHY_CTRL] & MII_CR_RESTART_AUTO_NEG &&
+ !(s->phy_reg[PHY_STATUS] & MII_SR_AUTONEG_COMPLETE)) {
+ nc->link_down = false;
+ qemu_mod_timer(s->autoneg_timer, qemu_get_clock_ms(vm_clock) + 500);
+ }
return 0;
}
@@ -1127,6 +1162,7 @@ static const VMStateDescription vmstate_e1000 = {
.version_id = 2,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
+ .pre_save = e1000_pre_save,
.post_load = e1000_post_load,
.fields = (VMStateField []) {
VMSTATE_PCI_DEVICE(dev, E1000State),
--
MST
- [Qemu-devel] [PATCH] e1000: fix link down handling with auto negotiation,
Michael S. Tsirkin <=