/*
 * mce.c - x86 Machine Check Exception Reporting
 * (c) 2002 Alan Cox <alan@redhat.com>, Dave Jones <davej@codemonkey.org.uk>
 */

#include <xen/init.h>
#include <xen/types.h>
#include <xen/kernel.h>
#include <xen/config.h>
#include <xen/smp.h>
#include <xen/errno.h>
#include <xen/console.h>
#include <xen/sched.h>
#include <xen/sched-if.h>
#include <xen/cpumask.h>
#include <xen/event.h>
#include <xen/guest_access.h>
#include <xen/hypercall.h> /* for do_mca */
#include <xen/cpu.h>

#include <asm/processor.h>
#include <asm/system.h>
#include <asm/msr.h>

#include "mce.h"
#include "barrier.h"
#include "mcaction.h"
#include "util.h"
#include "vmce.h"

bool_t __read_mostly mce_disabled;
invbool_param("mce", mce_disabled);
bool_t __read_mostly mce_broadcast = 0;
bool_t is_mc_panic;
unsigned int __read_mostly nr_mce_banks;
unsigned int __read_mostly firstbank;
uint8_t __read_mostly cmci_apic_vector;

DEFINE_PER_CPU_READ_MOSTLY(struct mca_banks *, poll_bankmask);
DEFINE_PER_CPU_READ_MOSTLY(struct mca_banks *, no_cmci_banks);
DEFINE_PER_CPU_READ_MOSTLY(struct mca_banks *, mce_clear_banks);

static void intpose_init(void);
static void mcinfo_clear(struct mc_info *);
struct mca_banks *mca_allbanks;

#define SEG_PL(segsel)   ((segsel) & 0x3)
#define _MC_MSRINJ_F_REQ_HWCR_WREN (1 << 16)

#if 0
static int x86_mcerr(const char *msg, int err)
{
    gdprintk(XENLOG_WARNING, "x86_mcerr: %s, returning %d\n",
             msg != NULL ? msg : "", err);
    return err;
}
#else
#define x86_mcerr(msg, err) (err)
#endif

int mce_verbosity;
static void __init mce_set_verbosity(char *str)
{
    if (strcmp("verbose", str) == 0)
        mce_verbosity = MCE_VERBOSE;
    else
        printk(KERN_DEBUG "Machine Check verbosity level %s not recognised"
               "use mce_verbosity=verbose", str);
}
custom_param("mce_verbosity", mce_set_verbosity);

/* Handle unconfigured int18 (should never happen) */
static void unexpected_machine_check(struct cpu_user_regs *regs, long error_code)
{
    printk(XENLOG_ERR "CPU#%d: Unexpected int18 (Machine Check).\n",
           smp_processor_id());
}


static x86_mce_vector_t _machine_check_vector = unexpected_machine_check;

void x86_mce_vector_register(x86_mce_vector_t hdlr)
{
    _machine_check_vector = hdlr;
    wmb();
}

/* Call the installed machine check handler for this CPU setup. */

void machine_check_vector(struct cpu_user_regs *regs, long error_code)
{
    _machine_check_vector(regs, error_code);
}

/* Init machine check callback handler
 * It is used to collect additional information provided by newer
 * CPU families/models without the need to duplicate the whole handler.
 * This avoids having many handlers doing almost nearly the same and each
 * with its own tweaks ands bugs. */
static x86_mce_callback_t mc_callback_bank_extended = NULL;

void x86_mce_callback_register(x86_mce_callback_t cbfunc)
{
    mc_callback_bank_extended = cbfunc;
}

/* Machine check recoverable judgement callback handler 
 * It is used to judge whether an UC error is recoverable by software
 */
static mce_recoverable_t mc_recoverable_scan = NULL;

void mce_recoverable_register(mce_recoverable_t cbfunc)
{
    mc_recoverable_scan = cbfunc;
}

struct mca_banks *mcabanks_alloc(void)
{
    struct mca_banks *mb;

    mb = xmalloc(struct mca_banks);
    if (!mb)
        return NULL;

    mb->bank_map = xzalloc_array(unsigned long,
                                 BITS_TO_LONGS(nr_mce_banks));
    if (!mb->bank_map)
    {
        xfree(mb);
        return NULL;
    }

    mb->num = nr_mce_banks;

    return mb;
}

void mcabanks_free(struct mca_banks *banks)
{
    if (banks == NULL)
        return;
    if (banks->bank_map)
        xfree(banks->bank_map);
    xfree(banks);
}

static void mcabank_clear(int banknum)
{
    uint64_t status;

    status = mca_rdmsr(MSR_IA32_MCx_STATUS(banknum));

    if (status & MCi_STATUS_ADDRV)
        mca_wrmsr(MSR_IA32_MCx_ADDR(banknum), 0x0ULL);
    if (status & MCi_STATUS_MISCV)
        mca_wrmsr(MSR_IA32_MCx_MISC(banknum), 0x0ULL);

    mca_wrmsr(MSR_IA32_MCx_STATUS(banknum), 0x0ULL);
}

/* Judging whether to Clear Machine Check error bank callback handler
 * According to Intel latest MCA OS Recovery Writer's Guide, 
 * whether the error MCA bank needs to be cleared is decided by the mca_source
 * and MCi_status bit value. 
 */
static mce_need_clearbank_t mc_need_clearbank_scan = NULL;

void mce_need_clearbank_register(mce_need_clearbank_t cbfunc)
{
    mc_need_clearbank_scan = cbfunc;
}


static struct mce_softirq_barrier mce_inside_bar, mce_severity_bar;
static struct mce_softirq_barrier mce_trap_bar;

/*
 * mce_logout_lock should only be used in the trap handler,
 * while MCIP has not been cleared yet in the global status
 * register. Other use is not safe, since an MCE trap can
 * happen at any moment, which would cause lock recursion.
 */
static DEFINE_SPINLOCK(mce_logout_lock);

static atomic_t severity_cpu = ATOMIC_INIT(-1);
static atomic_t found_error = ATOMIC_INIT(0);
static cpumask_t mce_fatal_cpus;

const struct mca_error_handler *__read_mostly mce_dhandlers;
const struct mca_error_handler *__read_mostly mce_uhandlers;
unsigned int __read_mostly mce_dhandler_num;
unsigned int __read_mostly mce_uhandler_num;


static void mca_init_bank(enum mca_source who,
    struct mc_info *mi, int bank)
{
    struct mcinfo_bank *mib;

    if (!mi)
        return;

    mib = x86_mcinfo_reserve(mi, sizeof(*mib));
    if (!mib)
    {
        mi->flags |= MCINFO_FLAGS_UNCOMPLETE;
        return;
    }

    mib->mc_status = mca_rdmsr(MSR_IA32_MCx_STATUS(bank));

    mib->common.type = MC_TYPE_BANK;
    mib->common.size = sizeof (struct mcinfo_bank);
    mib->mc_bank = bank;

    if (mib->mc_status & MCi_STATUS_MISCV)
        mib->mc_misc = mca_rdmsr(MSR_IA32_MCx_MISC(bank));

    if (mib->mc_status & MCi_STATUS_ADDRV)
        mib->mc_addr = mca_rdmsr(MSR_IA32_MCx_ADDR(bank));

    if ((mib->mc_status & MCi_STATUS_MISCV) &&
        (mib->mc_status & MCi_STATUS_ADDRV) &&
        (mc_check_addr(mib->mc_status, mib->mc_misc, MC_ADDR_PHYSICAL)) &&
        (who == MCA_POLLER || who == MCA_CMCI_HANDLER) &&
        (mfn_valid(paddr_to_pfn(mib->mc_addr))))
    {
        struct domain *d;

        d = maddr_get_owner(mib->mc_addr);
        if (d)
            mib->mc_domid = d->domain_id;
    }

    if (who == MCA_CMCI_HANDLER) {
        mib->mc_ctrl2 = mca_rdmsr(MSR_IA32_MC0_CTL2 + bank);
        rdtscll(mib->mc_tsc);
    }
}

static int mca_init_global(uint32_t flags, struct mcinfo_global *mig)
{
    uint64_t status;
    int cpu_nr;
    struct vcpu *v = current;
    struct domain *d;

    /* Set global information */
    mig->common.type = MC_TYPE_GLOBAL;
    mig->common.size = sizeof (struct mcinfo_global);
    status = mca_rdmsr(MSR_IA32_MCG_STATUS);
    mig->mc_gstatus = status;
    mig->mc_domid = mig->mc_vcpuid = -1;
    mig->mc_flags = flags;
    cpu_nr = smp_processor_id();
    /* Retrieve detector information */
    x86_mc_get_cpu_info(cpu_nr, &mig->mc_socketid,
                        &mig->mc_coreid, &mig->mc_core_threadid,
                        &mig->mc_apicid, NULL, NULL, NULL);

    /* This is really meaningless */
    if (v != NULL && ((d = v->domain) != NULL)) {
        mig->mc_domid = d->domain_id;
        mig->mc_vcpuid = v->vcpu_id;
    } else {
        mig->mc_domid = -1;
        mig->mc_vcpuid = -1;
    }

    return 0;
}

/* Utility function to perform MCA bank telemetry readout and to push that
 * telemetry towards an interested dom0 for logging and diagnosis.
 * The caller - #MC handler or MCA poll function - must arrange that we
 * do not migrate cpus. */

/* XXFM Could add overflow counting? */

/* Add out_param clear_bank for Machine Check Handler Caller.
 * For Intel latest CPU, whether to clear the error bank status needs to
 * be judged by the callback function defined above.
 */
mctelem_cookie_t
mcheck_mca_logout(enum mca_source who, struct mca_banks *bankmask,
                  struct mca_summary *sp, struct mca_banks *clear_bank)
{
    uint64_t gstatus, status;
    struct mcinfo_global *mig = NULL; /* on stack */
    mctelem_cookie_t mctc = NULL;
    bool_t uc = 0, pcc = 0, recover = 1, need_clear = 1;
    uint32_t mc_flags = 0;
    struct mc_info *mci = NULL;
    mctelem_class_t which = MC_URGENT; /* XXXgcc */
    int errcnt = 0;
    int i;

    gstatus = mca_rdmsr(MSR_IA32_MCG_STATUS);
    switch (who) {
    case MCA_MCE_SCAN:
        mc_flags = MC_FLAG_MCE;
        which = MC_URGENT;
        break;

    case MCA_POLLER:
    case MCA_RESET:
        mc_flags = MC_FLAG_POLLED;
        which = MC_NONURGENT;
        break;

    case MCA_CMCI_HANDLER:
        mc_flags = MC_FLAG_CMCI;
        which = MC_NONURGENT;
        break;

    default:
        BUG();
    }

    /* If no mc_recovery_scan callback handler registered,
     * this error is not recoverable
     */
    recover = (mc_recoverable_scan) ? 1 : 0;

    for (i = 0; i < nr_mce_banks; i++) {
        /* Skip bank if corresponding bit in bankmask is clear */
        if (!mcabanks_test(i, bankmask))
            continue;

        status = mca_rdmsr(MSR_IA32_MCx_STATUS(i));
        if (!(status & MCi_STATUS_VAL))
            continue; /* this bank has no valid telemetry */

        /* For Intel Latest CPU CMCI/MCE Handler caller, we need to
         * decide whether to clear bank by MCi_STATUS bit value such as
         * OVER/UC/EN/PCC/S/AR
         */
        if ( mc_need_clearbank_scan )
            need_clear = mc_need_clearbank_scan(who, status);

        /* If this is the first bank with valid MCA DATA, then
         * try to reserve an entry from the urgent/nonurgent queue
         * depending on whether we are called from an exception or
         * a poller;  this can fail (for example dom0 may not
         * yet have consumed past telemetry). */
        if (errcnt++ == 0) {
            if ( (mctc = mctelem_reserve(which)) != NULL ) {
                mci = mctelem_dataptr(mctc);
                mcinfo_clear(mci);
                mig = x86_mcinfo_reserve(mci, sizeof(*mig));
                /* mc_info should at least hold up the global information */
                ASSERT(mig);
                mca_init_global(mc_flags, mig);
                /* A hook here to get global extended msrs */
                {
                    if (boot_cpu_data.x86_vendor ==
                        X86_VENDOR_INTEL)
                        intel_get_extended_msrs(mig, mci);
                }
            }
        }

        /* flag for uncorrected errors */
        if (!uc && ((status & MCi_STATUS_UC) != 0))
            uc = 1;

        /* flag processor context corrupt */
        if (!pcc && ((status & MCi_STATUS_PCC) != 0))
            pcc = 1;

        if (recover && uc)
            /* uc = 1, recover = 1, we need not panic.
             */
            recover = mc_recoverable_scan(status);

        mca_init_bank(who, mci, i);

        if (mc_callback_bank_extended)
            mc_callback_bank_extended(mci, i, status);

        /* By default, need_clear = 1 */
        if (who != MCA_MCE_SCAN && need_clear)
            /* Clear bank */
            mcabank_clear(i);
        else if ( who == MCA_MCE_SCAN && need_clear)
            mcabanks_set(i, clear_bank);

        wmb();
    }

    if (mig && errcnt > 0) {
        if (pcc)
            mig->mc_flags |= MC_FLAG_UNCORRECTABLE;
        else if (uc)
            mig->mc_flags |= MC_FLAG_RECOVERABLE;
        else
            mig->mc_flags |= MC_FLAG_CORRECTABLE;
    }


    if (sp) {
        sp->errcnt = errcnt;
        sp->ripv = (gstatus & MCG_STATUS_RIPV) != 0;
        sp->eipv = (gstatus & MCG_STATUS_EIPV) != 0;
        sp->uc = uc;
        sp->pcc = pcc;
        sp->recoverable = recover;
    }

    return mci != NULL ? mctc : NULL; /* may be NULL */
}

static void mce_spin_lock(spinlock_t *lk)
{
      while (!spin_trylock(lk)) {
              cpu_relax();
              mce_panic_check();
      }
}

static void mce_spin_unlock(spinlock_t *lk)
{
      spin_unlock(lk);
}

static enum mce_result mce_action(struct cpu_user_regs *regs,
    mctelem_cookie_t mctc);

/*
 * Return:
 * -1: if system can't be recovered
 * 0: Continue to next step
 */
static int mce_urgent_action(struct cpu_user_regs *regs,
                              mctelem_cookie_t mctc)
{
    uint64_t gstatus;

    if ( mctc == NULL)
        return 0;

    gstatus = mca_rdmsr(MSR_IA32_MCG_STATUS);

    /*
     * FIXME: When RIPV = EIPV = 0, it's a little bit tricky. It may be an
     * asynchronic error, currently we have no way to precisely locate
     * whether the error occur at guest or hypervisor.
     * To avoid handling error in wrong way, we treat it as unrecovered.
     *
     * Another unrecovered case is RIPV = 0 while in hypervisor
     * since Xen is not pre-emptible.
     */
    if ( !(gstatus & MCG_STATUS_RIPV) &&
         (!(gstatus & MCG_STATUS_EIPV) || !guest_mode(regs)) )
        return -1;

    return mce_action(regs, mctc) == MCER_RESET ? -1 : 0;
}

/* Shared #MC handler. */
void mcheck_cmn_handler(struct cpu_user_regs *regs, long error_code,
    struct mca_banks *bankmask, struct mca_banks *clear_bank)
{
    uint64_t gstatus;
    mctelem_cookie_t mctc = NULL;
    struct mca_summary bs;

    mce_spin_lock(&mce_logout_lock);

    if (clear_bank != NULL) {
        memset( clear_bank->bank_map, 0x0,
            sizeof(long) * BITS_TO_LONGS(clear_bank->num));
    }
    mctc = mcheck_mca_logout(MCA_MCE_SCAN, bankmask, &bs, clear_bank);

    if (bs.errcnt) {
        /*
         * Uncorrected errors must be dealt with in softirq context.
         */
        if (bs.uc || bs.pcc) {
            add_taint(TAINT_MACHINE_CHECK);
            if (mctc != NULL)
                mctelem_defer(mctc);
            /*
             * For PCC=1 and can't be recovered, context is lost, so
             * reboot now without clearing the banks, and deal with
             * the telemetry after reboot (the MSRs are sticky)
             */
            if (bs.pcc || !bs.recoverable)
                cpumask_set_cpu(smp_processor_id(), &mce_fatal_cpus);
        } else {
            if (mctc != NULL)
                mctelem_commit(mctc);
        }
        atomic_set(&found_error, 1);

        /* The last CPU will be take check/clean-up etc */
        atomic_set(&severity_cpu, smp_processor_id());

        mce_printk(MCE_CRITICAL, "MCE: clear_bank map %lx on CPU%d\n",
                *((unsigned long*)clear_bank), smp_processor_id());
        if (clear_bank != NULL)
            mcheck_mca_clearbanks(clear_bank);
    } else {
        if (mctc != NULL)
            mctelem_dismiss(mctc);
    }
    mce_spin_unlock(&mce_logout_lock);

    mce_barrier_enter(&mce_trap_bar);
    if ( mctc != NULL && mce_urgent_action(regs, mctc))
        cpumask_set_cpu(smp_processor_id(), &mce_fatal_cpus);
    mce_barrier_exit(&mce_trap_bar);

    /*
     * Wait until everybody has processed the trap.
     */
    mce_barrier_enter(&mce_trap_bar);
    if (atomic_read(&severity_cpu) == smp_processor_id())
    {
        /* According to SDM, if no error bank found on any cpus,
         * something unexpected happening, we can't do any
         * recovery job but to reset the system.
         */
        if (atomic_read(&found_error) == 0)
            mc_panic("MCE: No CPU found valid MCE, need reset");
        if (!cpumask_empty(&mce_fatal_cpus))
        {
            char *ebufp, ebuf[96] = "MCE: Fatal error happened on CPUs ";
            ebufp = ebuf + strlen(ebuf);
            cpumask_scnprintf(ebufp, 95 - strlen(ebuf), &mce_fatal_cpus);
            mc_panic(ebuf);
        }
        atomic_set(&found_error, 0);
    }
    mce_barrier_exit(&mce_trap_bar); 

    /* Clear flags after above fatal check */
    mce_barrier_enter(&mce_trap_bar);
    gstatus = mca_rdmsr(MSR_IA32_MCG_STATUS);
    if ((gstatus & MCG_STATUS_MCIP) != 0) {
        mce_printk(MCE_CRITICAL, "MCE: Clear MCIP@ last step");
        mca_wrmsr(MSR_IA32_MCG_STATUS, gstatus & ~MCG_STATUS_MCIP);
    }
    mce_barrier_exit(&mce_trap_bar);

    raise_softirq(MACHINE_CHECK_SOFTIRQ);
}

void mcheck_mca_clearbanks(struct mca_banks *bankmask)
{
    int i;

    for (i = 0; i < nr_mce_banks; i++) {
        if (!mcabanks_test(i, bankmask))
            continue;
        mcabank_clear(i);
    }
}

/*check the existence of Machine Check*/
int mce_available(struct cpuinfo_x86 *c)
{
    return cpu_has(c, X86_FEATURE_MCE) && cpu_has(c, X86_FEATURE_MCA);
}

/*
 * Check if bank 0 is usable for MCE. It isn't for Intel P6 family
 * before model 0x1a.
 */
unsigned int mce_firstbank(struct cpuinfo_x86 *c)
{
    if (c->x86 == 6) {
        if (c->x86_vendor == X86_VENDOR_INTEL && c->x86_model < 0x1a)
            return 1;
    }

    return 0;
}

int show_mca_info(int inited, struct cpuinfo_x86 *c)
{
    static enum mcheck_type g_type = mcheck_unset;

    if (inited != g_type) {
        char prefix[20];
        static const char *const type_str[] = {
            [mcheck_amd_famXX] = "AMD",
            [mcheck_amd_k8] = "AMD K8",
            [mcheck_intel] = "Intel"
        };

        snprintf(prefix, ARRAY_SIZE(prefix),
                 g_type != mcheck_unset ? XENLOG_WARNING "CPU%i: "
                 : XENLOG_INFO,
                 smp_processor_id());
        BUG_ON(inited >= ARRAY_SIZE(type_str));
        switch (inited) {
        default:
            printk("%s%s machine check reporting enabled\n",
                   prefix, type_str[inited]);
            break;
        case mcheck_amd_famXX:
            printk("%s%s Fam%xh machine check reporting enabled\n",
                   prefix, type_str[inited], c->x86);
            break;
        case mcheck_none:
            printk("%sNo machine check initialization\n", prefix);
            break;
        }
        g_type = inited;
    }

    return 0;
}

static void set_poll_bankmask(struct cpuinfo_x86 *c)
{
    int cpu = smp_processor_id();
    struct mca_banks *mb;

    mb = per_cpu(poll_bankmask, cpu);
    BUG_ON(!mb);

    if (cmci_support && !mce_disabled) {
        mb->num = per_cpu(no_cmci_banks, cpu)->num;
        bitmap_copy(mb->bank_map, per_cpu(no_cmci_banks, cpu)->bank_map,
                    nr_mce_banks);
    }
    else {
        bitmap_copy(mb->bank_map, mca_allbanks->bank_map, nr_mce_banks);
        if (mce_firstbank(c))
            mcabanks_clear(0, mb);
    }
}

/* The perbank ctl/status init is platform specific because of AMD's quirk */
int mca_cap_init(void)
{
    uint64_t msr_content;

    rdmsrl(MSR_IA32_MCG_CAP, msr_content);

    if (msr_content & MCG_CTL_P) /* Control register present ? */
        wrmsrl(MSR_IA32_MCG_CTL, 0xffffffffffffffffULL);

    if (nr_mce_banks && (msr_content & MCG_CAP_COUNT) != nr_mce_banks)
    {
        dprintk(XENLOG_WARNING, "Different bank number on cpu %x\n",
                smp_processor_id());
        return -ENODEV;
    }
    nr_mce_banks = msr_content & MCG_CAP_COUNT;

    if (!nr_mce_banks)
    {
        printk(XENLOG_INFO "CPU%u: No MCE banks present. "
               "Machine check support disabled\n", smp_processor_id());
        return -ENODEV;
    }

    /* mcabanks_alloc depends on nr_mce_banks */
    if (!mca_allbanks)
    {
        int i;

        mca_allbanks = mcabanks_alloc();
        for ( i = 0; i < nr_mce_banks; i++)
            mcabanks_set(i, mca_allbanks);
    }

    return mca_allbanks ? 0:-ENOMEM;
}

static void cpu_bank_free(unsigned int cpu)
{
    struct mca_banks *poll = per_cpu(poll_bankmask, cpu);
    struct mca_banks *clr = per_cpu(mce_clear_banks, cpu);

    mcabanks_free(poll);
    mcabanks_free(clr);
}

static int cpu_bank_alloc(unsigned int cpu)
{
    struct mca_banks *poll = mcabanks_alloc();
    struct mca_banks *clr = mcabanks_alloc();

    if ( !poll || !clr )
    {
        mcabanks_free(poll);
        mcabanks_free(clr);
        return -ENOMEM;
    }

    per_cpu(poll_bankmask, cpu) = poll;
    per_cpu(mce_clear_banks, cpu) = clr;
    return 0;
}

static int cpu_callback(
    struct notifier_block *nfb, unsigned long action, void *hcpu)
{
    unsigned int cpu = (unsigned long)hcpu;
    int rc = 0;

    switch ( action )
    {
    case CPU_UP_PREPARE:
        rc = cpu_bank_alloc(cpu);
        break;
    case CPU_UP_CANCELED:
    case CPU_DEAD:
        cpu_bank_free(cpu);
        break;
    default:
        break;
    }

    return !rc ? NOTIFY_DONE : notifier_from_errno(rc);
}

static struct notifier_block cpu_nfb = {
    .notifier_call = cpu_callback
};

/* This has to be run for each processor */
void mcheck_init(struct cpuinfo_x86 *c, bool_t bsp)
{
    enum mcheck_type inited = mcheck_none;

    if (mce_disabled == 1) {
        dprintk(XENLOG_INFO, "MCE support disabled by bootparam\n");
        return;
    }

    if (!mce_available(c))
    {
        printk(XENLOG_INFO "CPU%i: No machine check support available\n",
               smp_processor_id());
        return;
    }

    /*Hardware Enable */
    if (mca_cap_init())
        return;

    /* Early MCE initialisation for BSP. */
    if ( bsp && cpu_bank_alloc(smp_processor_id()) )
        BUG();

    switch (c->x86_vendor) {
    case X86_VENDOR_AMD:
        inited = amd_mcheck_init(c);
        break;

    case X86_VENDOR_INTEL:
        switch (c->x86) {
        case 6:
        case 15:
            inited = intel_mcheck_init(c, bsp);
            break;
        }
        break;

    default:
        break;
    }

    show_mca_info(inited, c);
    if (inited == mcheck_none || inited == mcheck_unset)
        goto out;

    intpose_init();

    mctelem_init(sizeof(struct mc_info));

    /* Turn on MCE now */
    set_in_cr4(X86_CR4_MCE);

    if ( bsp )
        register_cpu_notifier(&cpu_nfb);
    set_poll_bankmask(c);

    return;
 out:
    if ( bsp )
    {
        cpu_bank_free(smp_processor_id());
        mcabanks_free(mca_allbanks);
        mca_allbanks = NULL;
    }
}

static void mcinfo_clear(struct mc_info *mi)
{
    memset(mi, 0, sizeof(struct mc_info));
    x86_mcinfo_nentries(mi) = 0;
}

void *x86_mcinfo_reserve(struct mc_info *mi, int size)
{
    int i;
    unsigned long end1, end2;
    struct mcinfo_common *mic_base, *mic_index;

    mic_index = mic_base = x86_mcinfo_first(mi);

    /* go to first free entry */
    for (i = 0; i < x86_mcinfo_nentries(mi); i++) {
        mic_index = x86_mcinfo_next(mic_index);
    }

    /* check if there is enough size */
    end1 = (unsigned long)((uint8_t *)mic_base + sizeof(struct mc_info));
    end2 = (unsigned long)((uint8_t *)mic_index + size);

    if (end1 < end2)
    {
        mce_printk(MCE_CRITICAL,
                   "mcinfo_add: No space left in mc_info\n");
        return NULL;
    }

    /* there's enough space. add entry. */
    x86_mcinfo_nentries(mi)++;

    return memset(mic_index, 0, size);
}

void *x86_mcinfo_add(struct mc_info *mi, void *mcinfo)
{
    struct mcinfo_common *mic, *buf;

    mic = (struct mcinfo_common *)mcinfo;
    buf = x86_mcinfo_reserve(mi, mic->size);

    if ( !buf )
        mce_printk(MCE_CRITICAL,
                   "mcinfo_add: No space left in mc_info\n");
    else
        memcpy(buf, mic, mic->size);

    return buf;
}

static void x86_mcinfo_apei_save(
    struct mcinfo_global *mc_global, struct mcinfo_bank *mc_bank)
{
    struct mce m;

    memset(&m, 0, sizeof(struct mce));

    m.cpu = mc_global->mc_coreid;
    m.cpuvendor = boot_cpu_data.x86_vendor;
    m.cpuid = cpuid_eax(1);
    m.socketid = mc_global->mc_socketid;
    m.apicid = mc_global->mc_apicid;

    m.mcgstatus = mc_global->mc_gstatus;
    m.status = mc_bank->mc_status;
    m.misc = mc_bank->mc_misc;
    m.addr = mc_bank->mc_addr;
    m.bank = mc_bank->mc_bank;

    apei_write_mce(&m);
}

/* Dump machine check information in a format,
 * mcelog can parse. This is used only when
 * Dom0 does not take the notification. */
void x86_mcinfo_dump(struct mc_info *mi)
{
    struct mcinfo_common *mic = NULL;
    struct mcinfo_global *mc_global;
    struct mcinfo_bank *mc_bank;

    /* first print the global info */
    x86_mcinfo_lookup(mic, mi, MC_TYPE_GLOBAL);
    if (mic == NULL)
        return;
    mc_global = (struct mcinfo_global *)mic;
    if (mc_global->mc_flags & MC_FLAG_MCE) {
        printk(XENLOG_WARNING
               "CPU%d: Machine Check Exception: %16"PRIx64"\n",
               mc_global->mc_coreid, mc_global->mc_gstatus);
    } else if (mc_global->mc_flags & MC_FLAG_CMCI) {
        printk(XENLOG_WARNING "CMCI occurred on CPU %d.\n", 
               mc_global->mc_coreid);
    } else if (mc_global->mc_flags & MC_FLAG_POLLED) {
        printk(XENLOG_WARNING "POLLED occurred on CPU %d.\n",
               mc_global->mc_coreid);
    }

    /* then the bank information */
    x86_mcinfo_lookup(mic, mi, MC_TYPE_BANK); /* finds the first entry */
    do {
        if (mic == NULL)
            return;
        if (mic->type != MC_TYPE_BANK)
            goto next;

        mc_bank = (struct mcinfo_bank *)mic;

        printk(XENLOG_WARNING "Bank %d: %16"PRIx64,
               mc_bank->mc_bank,
               mc_bank->mc_status);
        if (mc_bank->mc_status & MCi_STATUS_MISCV)
            printk("[%16"PRIx64"]", mc_bank->mc_misc);
        if (mc_bank->mc_status & MCi_STATUS_ADDRV)
            printk(" at %16"PRIx64, mc_bank->mc_addr);
        printk("\n");

        if (is_mc_panic)
            x86_mcinfo_apei_save(mc_global, mc_bank);

    next:
        mic = x86_mcinfo_next(mic); /* next entry */
        if ((mic == NULL) || (mic->size == 0))
            break;
    } while (1);
}

static void do_mc_get_cpu_info(void *v)
{
    int cpu = smp_processor_id();
    int cindex, cpn;
    struct cpuinfo_x86 *c;
    xen_mc_logical_cpu_t *log_cpus, *xcp;
    uint32_t junk, ebx;

    log_cpus = v;
    c = &cpu_data[cpu];
    cindex = 0;
    cpn = cpu - 1;

    /*
     * Deal with sparse masks, condensed into a contig array.
     */
    while (cpn >= 0) {
        if (cpu_online(cpn))
            cindex++;
        cpn--;
    }

    xcp = &log_cpus[cindex];
    c = &cpu_data[cpu];
    xcp->mc_cpunr = cpu;
    x86_mc_get_cpu_info(cpu, &xcp->mc_chipid,
                        &xcp->mc_coreid, &xcp->mc_threadid,
                        &xcp->mc_apicid, &xcp->mc_ncores,
                        &xcp->mc_ncores_active, &xcp->mc_nthreads);
    xcp->mc_cpuid_level = c->cpuid_level;
    xcp->mc_family = c->x86;
    xcp->mc_vendor = c->x86_vendor;
    xcp->mc_model = c->x86_model;
    xcp->mc_step = c->x86_mask;
    xcp->mc_cache_size = c->x86_cache_size;
    xcp->mc_cache_alignment = c->x86_cache_alignment;
    memcpy(xcp->mc_vendorid, c->x86_vendor_id, sizeof xcp->mc_vendorid);
    memcpy(xcp->mc_brandid, c->x86_model_id, sizeof xcp->mc_brandid);
    memcpy(xcp->mc_cpu_caps, c->x86_capability, sizeof xcp->mc_cpu_caps);

    /*
     * This part needs to run on the CPU itself.
     */
    xcp->mc_nmsrvals = __MC_NMSRS;
    xcp->mc_msrvalues[0].reg = MSR_IA32_MCG_CAP;
    rdmsrl(MSR_IA32_MCG_CAP, xcp->mc_msrvalues[0].value);

    if (c->cpuid_level >= 1) {
        cpuid(1, &junk, &ebx, &junk, &junk);
        xcp->mc_clusterid = (ebx >> 24) & 0xff;
    } else
        xcp->mc_clusterid = hard_smp_processor_id();
}


void x86_mc_get_cpu_info(unsigned cpu, uint32_t *chipid, uint16_t *coreid,
                         uint16_t *threadid, uint32_t *apicid,
                         unsigned *ncores, unsigned *ncores_active,
                         unsigned *nthreads)
{
    struct cpuinfo_x86 *c;

    *apicid = cpu_physical_id(cpu);
    c = &cpu_data[cpu];
    if (c->apicid == BAD_APICID) {
        *chipid = cpu;
        *coreid = 0;
        *threadid = 0;
        if (ncores != NULL)
            *ncores = 1;
        if (ncores_active != NULL)
            *ncores_active = 1;
        if (nthreads != NULL)
            *nthreads = 1;
    } else {
        *chipid = c->phys_proc_id;
        if (c->x86_max_cores > 1)
            *coreid = c->cpu_core_id;
        else
            *coreid = 0;
        *threadid = c->apicid & ((1 << (c->x86_num_siblings - 1)) - 1);
        if (ncores != NULL)
            *ncores = c->x86_max_cores;
        if (ncores_active != NULL)
            *ncores_active = c->booted_cores;
        if (nthreads != NULL)
            *nthreads = c->x86_num_siblings;
    }
}

#define INTPOSE_NENT 50

static struct intpose_ent {
    unsigned  int cpu_nr;
    uint64_t msr;
    uint64_t val;
} intpose_arr[INTPOSE_NENT];

static void intpose_init(void)
{
    static int done;
    int i;

    if (done++ > 0)
        return;

    for (i = 0; i < INTPOSE_NENT; i++) {
        intpose_arr[i].cpu_nr = -1;
    }

}

struct intpose_ent *intpose_lookup(unsigned int cpu_nr, uint64_t msr,
                                   uint64_t *valp)
{
    int i;

    for (i = 0; i < INTPOSE_NENT; i++) {
        if (intpose_arr[i].cpu_nr == cpu_nr &&
            intpose_arr[i].msr == msr) {
            if (valp != NULL)
                *valp = intpose_arr[i].val;
            return &intpose_arr[i];
        }
    }

    return NULL;
}

static void intpose_add(unsigned int cpu_nr, uint64_t msr, uint64_t val)
{
    struct intpose_ent *ent;
    int i;

    if ((ent = intpose_lookup(cpu_nr, msr, NULL)) != NULL) {
        ent->val = val;
        return;
    }

    for (i = 0, ent = &intpose_arr[0]; i < INTPOSE_NENT; i++, ent++) {
        if (ent->cpu_nr == -1) {
            ent->cpu_nr = cpu_nr;
            ent->msr = msr;
            ent->val = val;
            return;
        }
    }

    printk("intpose_add: interpose array full - request dropped\n");
}

bool_t intpose_inval(unsigned int cpu_nr, uint64_t msr)
{
    struct intpose_ent *ent = intpose_lookup(cpu_nr, msr, NULL);

    if ( !ent )
        return 0;

    ent->cpu_nr = -1;
    return 1;
}

#define IS_MCA_BANKREG(r) \
    ((r) >= MSR_IA32_MC0_CTL && \
    (r) <= MSR_IA32_MCx_MISC(nr_mce_banks - 1) && \
    ((r) - MSR_IA32_MC0_CTL) % 4 != 0) /* excludes MCi_CTL */

static int x86_mc_msrinject_verify(struct xen_mc_msrinject *mci)
{
    struct cpuinfo_x86 *c;
    int i, errs = 0;

    c = &cpu_data[smp_processor_id()];

    for (i = 0; i < mci->mcinj_count; i++) {
        uint64_t reg = mci->mcinj_msr[i].reg;
        const char *reason = NULL;

        if (IS_MCA_BANKREG(reg)) {
            if (c->x86_vendor == X86_VENDOR_AMD) {
                /* On AMD we can set MCi_STATUS_WREN in the
                 * HWCR MSR to allow non-zero writes to banks
                 * MSRs not to #GP.  The injector in dom0
                 * should set that bit, but we detect when it
                 * is necessary and set it as a courtesy to
                 * avoid #GP in the hypervisor. */
                mci->mcinj_flags |=
                    _MC_MSRINJ_F_REQ_HWCR_WREN;
                continue;
            } else {
                /* No alternative but to interpose, so require
                 * that the injector specified as such. */
                if (!(mci->mcinj_flags &
                      MC_MSRINJ_F_INTERPOSE)) {
                    reason = "must specify interposition";
                }
            }
        } else {
            switch (reg) {
                /* MSRs acceptable on all x86 cpus */
            case MSR_IA32_MCG_STATUS:
                break;

            case MSR_F10_MC4_MISC1:
            case MSR_F10_MC4_MISC2:
            case MSR_F10_MC4_MISC3:
                if (c->x86_vendor != X86_VENDOR_AMD)
                    reason = "only supported on AMD";
                else if (c->x86 < 0x10)
                    reason = "only supported on AMD Fam10h+";
                break;

                /* MSRs that the HV will take care of */
            case MSR_K8_HWCR:
                if (c->x86_vendor == X86_VENDOR_AMD)
                    reason = "HV will operate HWCR";
                else
                    reason ="only supported on AMD";
                break;

            default:
                reason = "not a recognized MCA MSR";
                break;
            }
        }

        if (reason != NULL) {
            printk("HV MSR INJECT ERROR: MSR %#Lx %s\n",
                   (unsigned long long)mci->mcinj_msr[i].reg, reason);
            errs++;
        }
    }

    return !errs;
}

static uint64_t x86_mc_hwcr_wren(void)
{
    uint64_t old;

    rdmsrl(MSR_K8_HWCR, old);

    if (!(old & K8_HWCR_MCi_STATUS_WREN)) {
        uint64_t new = old | K8_HWCR_MCi_STATUS_WREN;
        wrmsrl(MSR_K8_HWCR, new);
    }

    return old;
}

static void x86_mc_hwcr_wren_restore(uint64_t hwcr)
{
    if (!(hwcr & K8_HWCR_MCi_STATUS_WREN))
        wrmsrl(MSR_K8_HWCR, hwcr);
}

static void x86_mc_msrinject(void *data)
{
    struct xen_mc_msrinject *mci = data;
    struct mcinfo_msr *msr;
    uint64_t hwcr = 0;
    int intpose;
    int i;

    if (mci->mcinj_flags & _MC_MSRINJ_F_REQ_HWCR_WREN)
        hwcr = x86_mc_hwcr_wren();

    intpose = (mci->mcinj_flags & MC_MSRINJ_F_INTERPOSE) != 0;

    for (i = 0, msr = &mci->mcinj_msr[0];
         i < mci->mcinj_count; i++, msr++) {
        printk("HV MSR INJECT (%s) target %u actual %u MSR %#Lx <-- %#Lx\n",
               intpose ?  "interpose" : "hardware",
               mci->mcinj_cpunr, smp_processor_id(),
               (unsigned long long)msr->reg,
               (unsigned long long)msr->value);

        if (intpose)
            intpose_add(mci->mcinj_cpunr, msr->reg, msr->value);
        else
            wrmsrl(msr->reg, msr->value);
    }

    if (mci->mcinj_flags & _MC_MSRINJ_F_REQ_HWCR_WREN)
        x86_mc_hwcr_wren_restore(hwcr);
}

/*ARGSUSED*/
static void x86_mc_mceinject(void *data)
{
    printk("Simulating #MC on cpu %d\n", smp_processor_id());
    __asm__ __volatile__("int $0x12");
}

#if BITS_PER_LONG == 64

#define ID2COOKIE(id) ((mctelem_cookie_t)(id))
#define COOKIE2ID(c) ((uint64_t)(c))

#elif defined(BITS_PER_LONG)
#error BITS_PER_LONG has unexpected value
#else
#error BITS_PER_LONG definition absent
#endif

# include <compat/arch-x86/xen-mca.h>

# define xen_mcinfo_msr              mcinfo_msr
CHECK_mcinfo_msr;
# undef xen_mcinfo_msr
# undef CHECK_mcinfo_msr
# define CHECK_mcinfo_msr            struct mcinfo_msr

# define xen_mcinfo_common           mcinfo_common
CHECK_mcinfo_common;
# undef xen_mcinfo_common
# undef CHECK_mcinfo_common
# define CHECK_mcinfo_common         struct mcinfo_common

CHECK_FIELD_(struct, mc_fetch, flags);
CHECK_FIELD_(struct, mc_fetch, fetch_id);
# define CHECK_compat_mc_fetch       struct mc_fetch

CHECK_FIELD_(struct, mc_physcpuinfo, ncpus);
# define CHECK_compat_mc_physcpuinfo struct mc_physcpuinfo

#define CHECK_compat_mc_inject_v2   struct mc_inject_v2
CHECK_mc;
# undef CHECK_compat_mc_fetch
# undef CHECK_compat_mc_physcpuinfo

# define xen_mc_info                 mc_info
CHECK_mc_info;
# undef xen_mc_info

# define xen_mcinfo_global           mcinfo_global
CHECK_mcinfo_global;
# undef xen_mcinfo_global

# define xen_mcinfo_bank             mcinfo_bank
CHECK_mcinfo_bank;
# undef xen_mcinfo_bank

# define xen_mcinfo_extended         mcinfo_extended
CHECK_mcinfo_extended;
# undef xen_mcinfo_extended

# define xen_mcinfo_recovery         mcinfo_recovery
# define xen_cpu_offline_action      cpu_offline_action
# define xen_page_offline_action     page_offline_action
CHECK_mcinfo_recovery;
# undef xen_cpu_offline_action
# undef xen_page_offline_action
# undef xen_mcinfo_recovery

/* Machine Check Architecture Hypercall */
long do_mca(XEN_GUEST_HANDLE_PARAM(xen_mc_t) u_xen_mc)
{
    long ret = 0;
    struct xen_mc curop, *op = &curop;
    struct vcpu *v = current;
    union {
        struct xen_mc_fetch *nat;
        struct compat_mc_fetch *cmp;
    } mc_fetch;
    union {
        struct xen_mc_physcpuinfo *nat;
        struct compat_mc_physcpuinfo *cmp;
    } mc_physcpuinfo;
    uint32_t flags, cmdflags;
    int nlcpu;
    xen_mc_logical_cpu_t *log_cpus = NULL;
    mctelem_cookie_t mctc;
    mctelem_class_t which;
    unsigned int target;
    struct xen_mc_msrinject *mc_msrinject;
    struct xen_mc_mceinject *mc_mceinject;

    ret = xsm_do_mca(XSM_PRIV);
    if ( ret )
        return x86_mcerr(NULL, ret);

    if ( copy_from_guest(op, u_xen_mc, 1) )
        return x86_mcerr("do_mca: failed copyin of xen_mc_t", -EFAULT);

    if ( op->interface_version != XEN_MCA_INTERFACE_VERSION )
        return x86_mcerr("do_mca: interface version mismatch", -EACCES);

    switch (op->cmd) {
    case XEN_MC_fetch:
        mc_fetch.nat = &op->u.mc_fetch;
        cmdflags = mc_fetch.nat->flags;

        switch (cmdflags & (XEN_MC_NONURGENT | XEN_MC_URGENT)) {
        case XEN_MC_NONURGENT:
            which = MC_NONURGENT;
            break;

        case XEN_MC_URGENT:
            which = MC_URGENT;
            break;

        default:
            return x86_mcerr("do_mca fetch: bad cmdflags", -EINVAL);
        }

        flags = XEN_MC_OK;

        if (cmdflags & XEN_MC_ACK) {
            mctelem_cookie_t cookie = ID2COOKIE(mc_fetch.nat->fetch_id);
            mctelem_ack(which, cookie);
        } else {
            if (!is_pv_32on64_vcpu(v)
                ? guest_handle_is_null(mc_fetch.nat->data)
                : compat_handle_is_null(mc_fetch.cmp->data))
                return x86_mcerr("do_mca fetch: guest buffer "
                                 "invalid", -EINVAL);

            if ((mctc = mctelem_consume_oldest_begin(which))) {
                struct mc_info *mcip = mctelem_dataptr(mctc);
                if (!is_pv_32on64_vcpu(v)
                    ? copy_to_guest(mc_fetch.nat->data, mcip, 1)
                    : copy_to_compat(mc_fetch.cmp->data,
                                     mcip, 1)) {
                    ret = -EFAULT;
                    flags |= XEN_MC_FETCHFAILED;
                    mc_fetch.nat->fetch_id = 0;
                } else {
                    mc_fetch.nat->fetch_id = COOKIE2ID(mctc);
                }
                mctelem_consume_oldest_end(mctc);
            } else {
                /* There is no data */
                flags |= XEN_MC_NODATA;
                mc_fetch.nat->fetch_id = 0;
            }

            mc_fetch.nat->flags = flags;
            if (copy_to_guest(u_xen_mc, op, 1) != 0)
                ret = -EFAULT;
        }

        break;

    case XEN_MC_notifydomain:
        return x86_mcerr("do_mca notify unsupported", -EINVAL);

    case XEN_MC_physcpuinfo:
        mc_physcpuinfo.nat = &op->u.mc_physcpuinfo;
        nlcpu = num_online_cpus();

        if (!is_pv_32on64_vcpu(v)
            ? !guest_handle_is_null(mc_physcpuinfo.nat->info)
            : !compat_handle_is_null(mc_physcpuinfo.cmp->info)) {
            if (mc_physcpuinfo.nat->ncpus <= 0)
                return x86_mcerr("do_mca cpuinfo: ncpus <= 0",
                                 -EINVAL);
            nlcpu = min(nlcpu, (int)mc_physcpuinfo.nat->ncpus);
            log_cpus = xmalloc_array(xen_mc_logical_cpu_t, nlcpu);
            if (log_cpus == NULL)
                return x86_mcerr("do_mca cpuinfo", -ENOMEM);
            on_each_cpu(do_mc_get_cpu_info, log_cpus, 1);
            if (!is_pv_32on64_vcpu(v)
                ? copy_to_guest(mc_physcpuinfo.nat->info,
                                log_cpus, nlcpu)
                : copy_to_compat(mc_physcpuinfo.cmp->info,
                                 log_cpus, nlcpu))
                ret = -EFAULT;
            xfree(log_cpus);
        }

        mc_physcpuinfo.nat->ncpus = nlcpu;

        if (copy_to_guest(u_xen_mc, op, 1))
            return x86_mcerr("do_mca cpuinfo", -EFAULT);

        break;

    case XEN_MC_msrinject:
        if (nr_mce_banks == 0)
            return x86_mcerr("do_mca inject", -ENODEV);

        mc_msrinject = &op->u.mc_msrinject;
        target = mc_msrinject->mcinj_cpunr;

        if (target >= nr_cpu_ids)
            return x86_mcerr("do_mca inject: bad target", -EINVAL);

        if (!cpu_online(target))
            return x86_mcerr("do_mca inject: target offline",
                             -EINVAL);

        if (mc_msrinject->mcinj_count == 0)
            return 0;

        if (!x86_mc_msrinject_verify(mc_msrinject))
            return x86_mcerr("do_mca inject: illegal MSR", -EINVAL);

        add_taint(TAINT_ERROR_INJECT);

        on_selected_cpus(cpumask_of(target), x86_mc_msrinject,
                         mc_msrinject, 1);

        break;

    case XEN_MC_mceinject:
        if (nr_mce_banks == 0)
            return x86_mcerr("do_mca #MC", -ENODEV);

        mc_mceinject = &op->u.mc_mceinject;
        target = mc_mceinject->mceinj_cpunr;

        if (target >= nr_cpu_ids)
            return x86_mcerr("do_mca #MC: bad target", -EINVAL);

        if (!cpu_online(target))
            return x86_mcerr("do_mca #MC: target offline", -EINVAL);

        add_taint(TAINT_ERROR_INJECT);

        if ( mce_broadcast )
            on_each_cpu(x86_mc_mceinject, mc_mceinject, 1);
        else
            on_selected_cpus(cpumask_of(target), x86_mc_mceinject,
                             mc_mceinject, 1);
        break;

    case XEN_MC_inject_v2:
    {
        const cpumask_t *cpumap;
        cpumask_var_t cmv;

        if (nr_mce_banks == 0)
            return x86_mcerr("do_mca #MC", -ENODEV);

        if ( op->u.mc_inject_v2.flags & XEN_MC_INJECT_CPU_BROADCAST )
            cpumap = &cpu_online_map;
        else
        {
            ret = xenctl_bitmap_to_cpumask(&cmv, &op->u.mc_inject_v2.cpumap);
            if ( ret )
                break;
            cpumap = cmv;
            if ( !cpumask_intersects(cpumap, &cpu_online_map) )
            {
                free_cpumask_var(cmv);
                ret = x86_mcerr("No online CPU passed\n", -EINVAL);
                break;
            }
            if ( !cpumask_subset(cpumap, &cpu_online_map) )
                dprintk(XENLOG_INFO,
                        "Not all required CPUs are online\n");
        }

        switch (op->u.mc_inject_v2.flags & XEN_MC_INJECT_TYPE_MASK)
        {
        case XEN_MC_INJECT_TYPE_MCE:
            if ( mce_broadcast &&
                 !cpumask_equal(cpumap, &cpu_online_map) )
                printk("Not trigger MCE on all CPUs, may HANG!\n");
            on_selected_cpus(cpumap, x86_mc_mceinject, NULL, 1);
            break;
        case XEN_MC_INJECT_TYPE_CMCI:
            if ( !cmci_apic_vector )
                ret = x86_mcerr(
                    "No CMCI supported in platform\n", -EINVAL);
            else
            {
                if ( cpumask_test_cpu(smp_processor_id(), cpumap) )
                    send_IPI_self(cmci_apic_vector);
                send_IPI_mask(cpumap, cmci_apic_vector);
            }
            break;
        default:
            ret = x86_mcerr("Wrong mca type\n", -EINVAL);
            break;
        }

        if (cpumap != &cpu_online_map)
            free_cpumask_var(cmv);

        break;
    }

    default:
        return x86_mcerr("do_mca: bad command", -EINVAL);
    }

    return ret;
}

int mcinfo_dumpped;
static int x86_mcinfo_dump_panic(mctelem_cookie_t mctc)
{
    struct mc_info *mcip = mctelem_dataptr(mctc);

    x86_mcinfo_dump(mcip);
    mcinfo_dumpped++;

    return 0;
}

/* XXX shall we dump commited mc_info?? */
static void mc_panic_dump(void)
{
    int cpu;

    dprintk(XENLOG_ERR, "Begin dump mc_info\n");
    for_each_online_cpu(cpu)
        mctelem_process_deferred(cpu, x86_mcinfo_dump_panic);
    dprintk(XENLOG_ERR, "End dump mc_info, %x mcinfo dumped\n", mcinfo_dumpped);
}

void mc_panic(char *s)
{
    is_mc_panic = 1;
    console_force_unlock();

    printk("Fatal machine check: %s\n", s);
    printk("\n"
           "****************************************\n"
           "\n"
           "   The processor has reported a hardware error which cannot\n"
           "   be recovered from.  Xen will now reboot the machine.\n");
    mc_panic_dump();
    panic("HARDWARE ERROR");
}

/* Machine Check owner judge algorithm:
 * When error happens, all cpus serially read its msr banks.
 * The first CPU who fetches the error bank's info will clear
 * this bank. Later readers can't get any information again.
 * The first CPU is the actual mce_owner
 *
 * For Fatal (pcc=1) error, it might cause machine crash
 * before we're able to log. For avoiding log missing, we adopt two
 * round scanning:
 * Round1: simply scan. If found pcc = 1 or ripv = 0, simply reset.
 * All MCE banks are sticky, when boot up, MCE polling mechanism
 * will help to collect and log those MCE errors.
 * Round2: Do all MCE processing logic as normal.
 */

/* Maybe called in MCE context, no lock, no printk */
static enum mce_result mce_action(struct cpu_user_regs *regs,
                      mctelem_cookie_t mctc)
{
    struct mc_info *local_mi;
    enum mce_result bank_result = MCER_NOERROR;
    enum mce_result worst_result = MCER_NOERROR;
    struct mcinfo_common *mic = NULL;
    struct mca_binfo binfo;
    const struct mca_error_handler *handlers = mce_dhandlers;
    unsigned int i, handler_num = mce_dhandler_num;

    /* When in mce context, regs is valid */
    if (regs)
    {
        handler_num = mce_uhandler_num;
        handlers = mce_uhandlers;
    }

    /* At least a default handler should be registerd */
    ASSERT(handler_num);

    local_mi = (struct mc_info*)mctelem_dataptr(mctc);
    x86_mcinfo_lookup(mic, local_mi, MC_TYPE_GLOBAL);
    if (mic == NULL) {
        printk(KERN_ERR "MCE: get local buffer entry failed\n ");
        return MCER_CONTINUE;
    }

    memset(&binfo, 0, sizeof(binfo));
    binfo.mig = (struct mcinfo_global *)mic;
    binfo.mi = local_mi;

    /* Processing bank information */
    x86_mcinfo_lookup(mic, local_mi, MC_TYPE_BANK);

    for ( ; bank_result != MCER_RESET && mic && mic->size;
          mic = x86_mcinfo_next(mic) )
    {
        if (mic->type != MC_TYPE_BANK) {
            continue;
        }
        binfo.mib = (struct mcinfo_bank*)mic;
        binfo.bank = binfo.mib->mc_bank;
        bank_result = MCER_NOERROR;
        for ( i = 0; i < handler_num; i++ ) {
            if (handlers[i].owned_error(binfo.mib->mc_status))
            {
                handlers[i].recovery_handler(&binfo, &bank_result, regs);
                if (worst_result < bank_result)
                    worst_result = bank_result;
                break;
            }
        }
        ASSERT(i != handler_num);
    }

    return worst_result;
}

/*
 * Called from mctelem_process_deferred. Return 1 if the telemetry
 * should be committed for dom0 consumption, 0 if it should be
 * dismissed.
 */
static int mce_delayed_action(mctelem_cookie_t mctc)
{
    enum mce_result result;
    int ret = 0;

    result = mce_action(NULL, mctc);

    switch (result)
    {
    case MCER_RESET:
        dprintk(XENLOG_ERR, "MCE delayed action failed\n");
        is_mc_panic = 1;
        x86_mcinfo_dump(mctelem_dataptr(mctc));
        panic("MCE: Software recovery failed for the UCR");
        break;
    case MCER_RECOVERED:
        dprintk(XENLOG_INFO, "MCE: Error is successfully recovered\n");
        ret  = 1;
        break;
    case MCER_CONTINUE:
        dprintk(XENLOG_INFO, "MCE: Error can't be recovered, "
            "system is tainted\n");
        x86_mcinfo_dump(mctelem_dataptr(mctc));
        ret = 1;
        break;
    default:
        ret = 0;
        break;
    }
    return ret;
}

/* Softirq Handler for this MCE# processing */
static void mce_softirq(void)
{
    int cpu = smp_processor_id();
    unsigned int workcpu;

    mce_printk(MCE_VERBOSE, "CPU%d enter softirq\n", cpu);

    mce_barrier_enter(&mce_inside_bar);

    /*
     * Everybody is here. Now let's see who gets to do the
     * recovery work. Right now we just see if there's a CPU
     * that did not have any problems, and pick that one.
     *
     * First, just set a default value: the last CPU who reaches this
     * will overwrite the value and become the default.
     */

    atomic_set(&severity_cpu, cpu);

    mce_barrier_enter(&mce_severity_bar);
    if (!mctelem_has_deferred(cpu))
        atomic_set(&severity_cpu, cpu);
    mce_barrier_exit(&mce_severity_bar);

    /* We choose severity_cpu for further processing */
    if (atomic_read(&severity_cpu) == cpu) {

        mce_printk(MCE_VERBOSE, "CPU%d handling errors\n", cpu);

        /* Step1: Fill DOM0 LOG buffer, vMCE injection buffer and
         * vMCE MSRs virtualization buffer
         */
        for_each_online_cpu(workcpu) {
            mctelem_process_deferred(workcpu, mce_delayed_action);
        }

        /* Step2: Send Log to DOM0 through vIRQ */
        if (dom0_vmce_enabled()) {
            mce_printk(MCE_VERBOSE, "MCE: send MCE# to DOM0 through virq\n");
            send_global_virq(VIRQ_MCA);
        }
    }

    mce_barrier_exit(&mce_inside_bar);
}

/* Machine Check owner judge algorithm:
 * When error happens, all cpus serially read its msr banks.
 * The first CPU who fetches the error bank's info will clear
 * this bank. Later readers can't get any infor again.
 * The first CPU is the actual mce_owner
 *
 * For Fatal (pcc=1) error, it might cause machine crash
 * before we're able to log. For avoiding log missing, we adopt two
 * round scanning:
 * Round1: simply scan. If found pcc = 1 or ripv = 0, simply reset.
 * All MCE banks are sticky, when boot up, MCE polling mechanism
 * will help to collect and log those MCE errors.
 * Round2: Do all MCE processing logic as normal.
 */
void mce_handler_init(void)
{
    if (smp_processor_id() != 0)
        return;

    /* callback register, do we really need so many callback? */
    /* mce handler data initialization */
    mce_barrier_init(&mce_inside_bar);
    mce_barrier_init(&mce_severity_bar);
    mce_barrier_init(&mce_trap_bar);
    spin_lock_init(&mce_logout_lock);
    open_softirq(MACHINE_CHECK_SOFTIRQ, mce_softirq);
}
