e1000: fix link down handling with auto negotiation

Fixes a couple of regression bugs introduced by
b9d03e352c 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 <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Michael S. Tsirkin 2013-02-05 21:00:21 +02:00 committed by Anthony Liguori
parent 84208085d3
commit ddcb73b778

View File

@ -166,7 +166,6 @@ 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");
@ -178,8 +177,9 @@ 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 +784,8 @@ 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 +811,13 @@ 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 +1116,37 @@ 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 +1156,7 @@ 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),