apic.c

xen虚拟机源代码安装包

/*
 *  APIC support
 * 
 *  Copyright (c) 2004-2005 Fabrice Bellard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include "vl.h"

//#define DEBUG_APIC
//#define DEBUG_IOAPIC

/* APIC Local Vector Table */
#define APIC_LVT_TIMER   0
#define APIC_LVT_THERMAL 1
#define APIC_LVT_PERFORM 2
#define APIC_LVT_LINT0   3
#define APIC_LVT_LINT1   4
#define APIC_LVT_ERROR   5
#define APIC_LVT_NB      6

/* APIC delivery modes */
#define APIC_DM_FIXED	0
#define APIC_DM_LOWPRI	1
#define APIC_DM_SMI	2
#define APIC_DM_NMI	4
#define APIC_DM_INIT	5
#define APIC_DM_SIPI	6
#define APIC_DM_EXTINT	7

/* APIC destination mode */
#define APIC_DESTMODE_FLAT	0xf
#define APIC_DESTMODE_CLUSTER	1

#define APIC_TRIGGER_EDGE  0
#define APIC_TRIGGER_LEVEL 1

#define	APIC_LVT_TIMER_PERIODIC		(1<<17)
#define	APIC_LVT_MASKED			(1<<16)
#define	APIC_LVT_LEVEL_TRIGGER		(1<<15)
#define	APIC_LVT_REMOTE_IRR		(1<<14)
#define	APIC_INPUT_POLARITY		(1<<13)
#define	APIC_SEND_PENDING		(1<<12)

#define IOAPIC_NUM_PINS			0x18

#define ESR_ILLEGAL_ADDRESS (1 << 7)

#define APIC_SV_ENABLE (1 << 8)

#define MAX_APICS 255
#define MAX_APIC_WORDS 8

typedef struct APICState {
    CPUState *cpu_env;
    uint32_t apicbase;
    uint8_t id;
    uint8_t arb_id;
    uint8_t tpr;
    uint32_t spurious_vec;
    uint8_t log_dest;
    uint8_t dest_mode;
    uint32_t isr[8];  /* in service register */
    uint32_t tmr[8];  /* trigger mode register */
    uint32_t irr[8]; /* interrupt request register */
    uint32_t lvt[APIC_LVT_NB];
    uint32_t esr; /* error register */
    uint32_t icr[2];

    uint32_t divide_conf;
    int count_shift;
    uint32_t initial_count;
    int64_t initial_count_load_time, next_time;
    QEMUTimer *timer;
} APICState;

struct IOAPICState {
    uint8_t id;
    uint8_t ioregsel;

    uint32_t irr;
    uint64_t ioredtbl[IOAPIC_NUM_PINS];
};

static int apic_io_memory;
static APICState *local_apics[MAX_APICS + 1];
static int last_apic_id = 0;

static void apic_init_ipi(APICState *s);
static void apic_set_irq(APICState *s, int vector_num, int trigger_mode);
static void apic_update_irq(APICState *s);

/* Find first bit starting from msb. Return 0 if value = 0 */
static int fls_bit(uint32_t value)
{
    unsigned int ret = 0;

#if defined(HOST_I386)
    __asm__ __volatile__ ("bsr %1, %0\n" : "+r" (ret) : "rm" (value));
    return ret;
#else
    if (value > 0xffff)
        value >>= 16, ret = 16;
    if (value > 0xff)
        value >>= 8, ret += 8;
    if (value > 0xf)
        value >>= 4, ret += 4;
    if (value > 0x3)
        value >>= 2, ret += 2;
    return ret + (value >> 1);
#endif
}

/* Find first bit starting from lsb. Return 0 if value = 0 */
static int ffs_bit(uint32_t value)
{
    unsigned int ret = 0;

#if defined(HOST_I386)
    __asm__ __volatile__ ("bsf %1, %0\n" : "+r" (ret) : "rm" (value));
    return ret;
#else
    if (!value)
        return 0;
    if (!(value & 0xffff))
        value >>= 16, ret = 16;
    if (!(value & 0xff))
        value >>= 8, ret += 8;
    if (!(value & 0xf))
        value >>= 4, ret += 4;
    if (!(value & 0x3))
        value >>= 2, ret += 2;
    if (!(value & 0x1))
        ret++;
    return ret;
#endif
}

static inline void set_bit(uint32_t *tab, int index)
{
    int i, mask;
    i = index >> 5;
    mask = 1 << (index & 0x1f);
    tab[i] |= mask;
}

static inline void reset_bit(uint32_t *tab, int index)
{
    int i, mask;
    i = index >> 5;
    mask = 1 << (index & 0x1f);
    tab[i] &= ~mask;
}

#define foreach_apic(apic, deliver_bitmask, code) \
{\
    int __i, __j, __mask;\
    for(__i = 0; __i < MAX_APIC_WORDS; __i++) {\
        __mask = deliver_bitmask[__i];\
        if (__mask) {\
            for(__j = 0; __j < 32; __j++) {\
                if (__mask & (1 << __j)) {\
                    apic = local_apics[__i * 32 + __j];\
                    if (apic) {\
                        code;\
                    }\
                }\
            }\
        }\
    }\
}

static void apic_bus_deliver(const uint32_t *deliver_bitmask, 
                             uint8_t delivery_mode,
                             uint8_t vector_num, uint8_t polarity,
                             uint8_t trigger_mode)
{
    APICState *apic_iter;

    switch (delivery_mode) {
        case APIC_DM_LOWPRI:
            /* XXX: search for focus processor, arbitration */
            {
                int i, d;
                d = -1;
                for(i = 0; i < MAX_APIC_WORDS; i++) {
                    if (deliver_bitmask[i]) {
                        d = i * 32 + ffs_bit(deliver_bitmask[i]);
                        break;
                    }
                }
                if (d >= 0) {
                    apic_iter = local_apics[d];
                    if (apic_iter) {
                        apic_set_irq(apic_iter, vector_num, trigger_mode);
                    }
                }
            }
            return;

        case APIC_DM_FIXED:
            break;

        case APIC_DM_SMI:
        case APIC_DM_NMI:
            break;

        case APIC_DM_INIT:
            /* normal INIT IPI sent to processors */
            foreach_apic(apic_iter, deliver_bitmask, 
                         apic_init_ipi(apic_iter) );
            return;
    
        case APIC_DM_EXTINT:
            /* handled in I/O APIC code */
            break;

        default:
            return;
    }

    foreach_apic(apic_iter, deliver_bitmask, 
                 apic_set_irq(apic_iter, vector_num, trigger_mode) );
}

void cpu_set_apic_base(CPUState *env, uint64_t val)
{
    APICState *s = env->apic_state;
#ifdef DEBUG_APIC
    printf("cpu_set_apic_base: %016" PRIx64 "\n", val);
#endif
    s->apicbase = (val & 0xfffff000) | 
        (s->apicbase & (MSR_IA32_APICBASE_BSP | MSR_IA32_APICBASE_ENABLE));
    /* if disabled, cannot be enabled again */
    if (!(val & MSR_IA32_APICBASE_ENABLE)) {
        s->apicbase &= ~MSR_IA32_APICBASE_ENABLE;
        env->cpuid_features &= ~CPUID_APIC;
        s->spurious_vec &= ~APIC_SV_ENABLE;
    }
}

uint64_t cpu_get_apic_base(CPUState *env)
{
    APICState *s = env->apic_state;
#ifdef DEBUG_APIC
    printf("cpu_get_apic_base: %016" PRIx64 "\n", (uint64_t)s->apicbase);
#endif
    return s->apicbase;
}

void cpu_set_apic_tpr(CPUX86State *env, uint8_t val)
{
    APICState *s = env->apic_state;
    s->tpr = (val & 0x0f) << 4;
    apic_update_irq(s);
}

uint8_t cpu_get_apic_tpr(CPUX86State *env)
{
    APICState *s = env->apic_state;
    return s->tpr >> 4;
}

/* return -1 if no bit is set */
static int get_highest_priority_int(uint32_t *tab)
{
    int i;
    for(i = 7; i >= 0; i--) {
        if (tab[i] != 0) {
            return i * 32 + fls_bit(tab[i]);
        }
    }
    return -1;
}

static int apic_get_ppr(APICState *s)
{
    int tpr, isrv, ppr;

    tpr = (s->tpr >> 4);
    isrv = get_highest_priority_int(s->isr);
    if (isrv < 0)
        isrv = 0;
    isrv >>= 4;
    if (tpr >= isrv)
        ppr = s->tpr;
    else
        ppr = isrv << 4;
    return ppr;
}

static int apic_get_arb_pri(APICState *s)
{
    /* XXX: arbitration */
    return 0;
}

/* signal the CPU if an irq is pending */
static void apic_update_irq(APICState *s)
{
    int irrv, ppr;
    if (!(s->spurious_vec & APIC_SV_ENABLE))
        return;
    irrv = get_highest_priority_int(s->irr);
    if (irrv < 0)
        return;
    ppr = apic_get_ppr(s);
    if (ppr && (irrv & 0xf0) <= (ppr & 0xf0))
        return;
    cpu_interrupt(s->cpu_env, CPU_INTERRUPT_HARD);
}

static void apic_set_irq(APICState *s, int vector_num, int trigger_mode)
{
    set_bit(s->irr, vector_num);
    if (trigger_mode)
        set_bit(s->tmr, vector_num);
    else
        reset_bit(s->tmr, vector_num);
    apic_update_irq(s);
}

static void apic_eoi(APICState *s)
{
    int isrv;
    isrv = get_highest_priority_int(s->isr);
    if (isrv < 0)
        return;
    reset_bit(s->isr, isrv);
    /* XXX: send the EOI packet to the APIC bus to allow the I/O APIC to
            set the remote IRR bit for level triggered interrupts. */
    apic_update_irq(s);
}

static void apic_get_delivery_bitmask(uint32_t *deliver_bitmask,
                                      uint8_t dest, uint8_t dest_mode)
{
    APICState *apic_iter;
    int i;

    if (dest_mode == 0) {
        if (dest == 0xff) {
            memset(deliver_bitmask, 0xff, MAX_APIC_WORDS * sizeof(uint32_t));
        } else {
            memset(deliver_bitmask, 0x00, MAX_APIC_WORDS * sizeof(uint32_t));
            set_bit(deliver_bitmask, dest);
        }
    } else {
        /* XXX: cluster mode */
        memset(deliver_bitmask, 0x00, MAX_APIC_WORDS * sizeof(uint32_t));
        for(i = 0; i < MAX_APICS; i++) {
            apic_iter = local_apics[i];
            if (apic_iter) {
                if (apic_iter->dest_mode == 0xf) {
                    if (dest & apic_iter->log_dest)
                        set_bit(deliver_bitmask, i);
                } else if (apic_iter->dest_mode == 0x0) {
                    if ((dest & 0xf0) == (apic_iter->log_dest & 0xf0) &&
                        (dest & apic_iter->log_dest & 0x0f)) {
                        set_bit(deliver_bitmask, i);
                    }
                }
            }
        }
    }
}


static void apic_init_ipi(APICState *s)
{
    int i;

    s->tpr = 0;
    s->spurious_vec = 0xff;
    s->log_dest = 0;
    s->dest_mode = 0xf;
    memset(s->isr, 0, sizeof(s->isr));
    memset(s->tmr, 0, sizeof(s->tmr));
    memset(s->irr, 0, sizeof(s->irr));
    for(i = 0; i < APIC_LVT_NB; i++)
        s->lvt[i] = 1 << 16; /* mask LVT */
    s->esr = 0;
    memset(s->icr, 0, sizeof(s->icr));
    s->divide_conf = 0;
    s->count_shift = 0;
    s->initial_count = 0;
    s->initial_count_load_time = 0;
    s->next_time = 0;
}

/* send a SIPI message to the CPU to start it */
static void apic_startup(APICState *s, int vector_num)
{
    CPUState *env = s->cpu_env;
    if (!(env->hflags & HF_HALTED_MASK))
        return;
    env->eip = 0;
    cpu_x86_load_seg_cache(env, R_CS, vector_num << 8, vector_num << 12, 
                           0xffff, 0);
    env->hflags &= ~HF_HALTED_MASK;
}

static void apic_deliver(APICState *s, uint8_t dest, uint8_t dest_mode,
                         uint8_t delivery_mode, uint8_t vector_num,
                         uint8_t polarity, uint8_t trigger_mode)
{
    uint32_t deliver_bitmask[MAX_APIC_WORDS];
    int dest_shorthand = (s->icr[0] >> 18) & 3;
    APICState *apic_iter;

    switch (dest_shorthand) {
    case 0:
        apic_get_delivery_bitmask(deliver_bitmask, dest, dest_mode);
        break;
    case 1:
        memset(deliver_bitmask, 0x00, sizeof(deliver_bitmask));
        set_bit(deliver_bitmask, s->id);
        break;
    case 2:
        memset(deliver_bitmask, 0xff, sizeof(deliver_bitmask));
        break;
    case 3:
        memset(deliver_bitmask, 0xff, sizeof(deliver_bitmask));
        reset_bit(deliver_bitmask, s->id);
        break;
    }

    switch (delivery_mode) {
        case APIC_DM_INIT:
            {
                int trig_mode = (s->icr[0] >> 15) & 1;
                int level = (s->icr[0] >> 14) & 1;
                if (level == 0 && trig_mode == 1) {
                    foreach_apic(apic_iter, deliver_bitmask, 
                                 apic_iter->arb_id = apic_iter->id );
                    return;
                }
            }
            break;

        case APIC_DM_SIPI:
            foreach_apic(apic_iter, deliver_bitmask, 
                         apic_startup(apic_iter, vector_num) );
            return;
    }

    apic_bus_deliver(deliver_bitmask, delivery_mode, vector_num, polarity,
                     trigger_mode);
}

int apic_get_interrupt(CPUState *env)
{
    APICState *s = env->apic_state;
    int intno;

    /* if the APIC is installed or enabled, we let the 8259 handle the
       IRQs */
    if (!s)
        return -1;
    if (!(s->spurious_vec & APIC_SV_ENABLE))
        return -1;
    
    /* XXX: spurious IRQ handling */
    intno = get_highest_priority_int(s->irr);
    if (intno < 0)
        return -1;
    if (s->tpr && intno <= s->tpr)
        return s->spurious_vec & 0xff;
    reset_bit(s->irr, intno);
    set_bit(s->isr, intno);
    apic_update_irq(s);
    return intno;
}

static uint32_t apic_get_current_count(APICState *s)
{
    int64_t d;
    uint32_t val;
    d = (qemu_get_clock(vm_clock) - s->initial_count_load_time) >> 
        s->count_shift;
    if (s->lvt[APIC_LVT_TIMER] & APIC_LVT_TIMER_PERIODIC) {
        /* periodic */
        val = s->initial_count - (d % ((uint64_t)s->initial_count + 1));
    } else {
        if (d >= s->initial_count)
            val = 0;
        else
            val = s->initial_count - d;
    }
    return val;
}

static void apic_timer_update(APICState *s, int64_t current_time)
{
    int64_t next_time, d;
    
    if (!(s->lvt[APIC_LVT_TIMER] & APIC_LVT_MASKED)) {
        d = (current_time - s->initial_count_load_time) >> 
            s->count_shift;
        if (s->lvt[APIC_LVT_TIMER] & APIC_LVT_TIMER_PERIODIC) {
            d = ((d / ((uint64_t)s->initial_count + 1)) + 1) * ((uint64_t)s->initial_count + 1);
        } else {
            if (d >= s->initial_count)
                goto no_timer;
            d = (uint64_t)s->initial_count + 1;
        }
        next_time = s->initial_count_load_time + (d << s->count_shift);
        qemu_mod_timer(s->timer, next_time);
        s->next_time = next_time;
    } else {
    no_timer:
        qemu_del_timer(s->timer);