Commit b9d03e35 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

e1000: link auto-negotiation emulation 



Indeed, there's nothing else except for the time spent on the
negotiation needs to be emulated. This is needed for resuming windows
guest from hibernation, as without a proper delay, qemu would send the
packet too early ( guest even does not have a proper intr handler),
which could lead windows guest hang.

This patch first introduces an array of function pointers to make it
possible to emulate per-register write behavior. Then traps the
PHY_CTRL register write and when guest want to restart the link auto
negotiation, we would down the link and mark the auto negotiation in
progress in PHY_STATUS register. After time, a timer with 500 ms (
which is the minimum timeout of auto-negotation specified in 802.3
spec). The link would be up when timer expired.

Test with resuming windows guest plus flood ping and linux ethtool
linkstatus test.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent f9c1cdf4

hw/e1000.c

+43 −2
Original line number Diff line number Diff line
@@ -125,6 +125,8 @@ typedef struct E1000State_st { 
        uint16_t reading;

        uint32_t old_eecd;

    } eecd_state;



    QEMUTimer *autoneg_timer;

} E1000State;



#define	defreg(x)	x = (E1000_##x>>2)
@@ -156,6 +158,34 @@ e1000_link_up(E1000State *s) 
    s->phy_reg[PHY_STATUS] |= MII_SR_LINK_STATUS;

}



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)) {

        s->nic->nc.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);

    }

}



static void

e1000_autoneg_timer(void *opaque)

{

    E1000State *s = opaque;

    s->nic->nc.link_down = false;

    e1000_link_up(s);

    s->phy_reg[PHY_STATUS] |= MII_SR_AUTONEG_COMPLETE;

    DBGOUT(PHY, "Auto negotiation is completed\n");

}



static void (*phyreg_writeops[])(E1000State *, int, uint16_t) = {

    [PHY_CTRL] = set_phy_ctrl,

};



enum { NPHYWRITEOPS = ARRAY_SIZE(phyreg_writeops) };



enum { PHY_R = 1, PHY_W = 2, PHY_RW = PHY_R | PHY_W };

static const char phy_regcap[0x20] = {

    [PHY_STATUS] = PHY_R,	[M88E1000_EXT_PHY_SPEC_CTRL] = PHY_RW,
@@ -167,7 +197,8 @@ static const char phy_regcap[0x20] = { 
};



static const uint16_t phy_reg_init[] = {

    [PHY_CTRL] = 0x1140,			[PHY_STATUS] = 0x796d, // link initially up

    [PHY_CTRL] = 0x1140,

    [PHY_STATUS] = 0x794d, /* link initially up with not completed autoneg */

    [PHY_ID1] = 0x141,				[PHY_ID2] = PHY_ID2_INIT,

    [PHY_1000T_CTRL] = 0x0e00,			[M88E1000_PHY_SPEC_CTRL] = 0x360,

    [M88E1000_EXT_PHY_SPEC_CTRL] = 0x0d60,	[PHY_AUTONEG_ADV] = 0xde1,
@@ -234,6 +265,7 @@ static void e1000_reset(void *opaque) 
{

    E1000State *d = opaque;



    qemu_del_timer(d->autoneg_timer);

    memset(d->phy_reg, 0, sizeof d->phy_reg);

    memmove(d->phy_reg, phy_reg_init, sizeof phy_reg_init);

    memset(d->mac_reg, 0, sizeof d->mac_reg);
@@ -283,9 +315,13 @@ set_mdic(E1000State *s, int index, uint32_t val) 
        if (!(phy_regcap[addr] & PHY_W)) {

            DBGOUT(MDIC, "MDIC write reg %x unhandled\n", addr);

            val |= E1000_MDIC_ERROR;

        } else

        } else {

            if (addr < NPHYWRITEOPS && phyreg_writeops[addr]) {

                phyreg_writeops[addr](s, index, data);

            }

            s->phy_reg[addr] = data;

        }

    }

    s->mac_reg[MDIC] = val | E1000_MDIC_READY;



    if (val & E1000_MDIC_INT_EN) {
@@ -965,6 +1001,7 @@ static void (*macreg_writeops[])(E1000State *, int, uint32_t) = { 
    [MTA ... MTA+127] = &mac_writereg,

    [VFTA ... VFTA+127] = &mac_writereg,

};



enum { NWRITEOPS = ARRAY_SIZE(macreg_writeops) };



static void
@@ -1158,6 +1195,8 @@ pci_e1000_uninit(PCIDevice *dev) 
{

    E1000State *d = DO_UPCAST(E1000State, dev, dev);



    qemu_del_timer(d->autoneg_timer);

    qemu_free_timer(d->autoneg_timer);

    memory_region_destroy(&d->mmio);

    memory_region_destroy(&d->io);

    qemu_del_vlan_client(&d->nic->nc);
@@ -1212,6 +1251,8 @@ static int pci_e1000_init(PCIDevice *pci_dev) 


    add_boot_device_path(d->conf.bootindex, &pci_dev->qdev, "/ethernet-phy@0");



    d->autoneg_timer = qemu_new_timer_ms(vm_clock, e1000_autoneg_timer, d);



    return 0;

}