/*
 * QEMU PowerPC pSeries Logical Partition capabilities handling
 *
 * Copyright (c) 2017 David Gibson, Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "sysemu/hw_accel.h"
#include "target/ppc/cpu.h"
#include "cpu-models.h"
#include "kvm_ppc.h"

#include "hw/ppc/spapr.h"

typedef struct sPAPRCapabilityInfo {
    const char *name;
    const char *description;
    int index;

    /* Getter and Setter Function Pointers */
    ObjectPropertyAccessor *get;
    ObjectPropertyAccessor *set;
    const char *type;
    /* Make sure the virtual hardware can support this capability */
    void (*apply)(sPAPRMachineState *spapr, uint8_t val, Error **errp);
} sPAPRCapabilityInfo;

static void spapr_cap_get_bool(Object *obj, Visitor *v, const char *name,
                               void *opaque, Error **errp)
{
    sPAPRCapabilityInfo *cap = opaque;
    sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
    bool value = spapr_get_cap(spapr, cap->index) == SPAPR_CAP_ON;

    visit_type_bool(v, name, &value, errp);
}

static void spapr_cap_set_bool(Object *obj, Visitor *v, const char *name,
                               void *opaque, Error **errp)
{
    sPAPRCapabilityInfo *cap = opaque;
    sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
    bool value;
    Error *local_err = NULL;

    visit_type_bool(v, name, &value, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        return;
    }

    spapr->cmd_line_caps[cap->index] = true;
    spapr->eff.caps[cap->index] = value ? SPAPR_CAP_ON : SPAPR_CAP_OFF;
}

static void cap_htm_apply(sPAPRMachineState *spapr, uint8_t val, Error **errp)
{
    if (!val) {
        /* TODO: We don't support disabling htm yet */
        return;
    }
    if (tcg_enabled()) {
        error_setg(errp,
                   "No Transactional Memory support in TCG, try cap-htm=off");
    } else if (kvm_enabled() && !kvmppc_has_cap_htm()) {
        error_setg(errp,
"KVM implementation does not support Transactional Memory, try cap-htm=off"
            );
    }
}

static void cap_vsx_apply(sPAPRMachineState *spapr, uint8_t val, Error **errp)
{
    PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
    CPUPPCState *env = &cpu->env;

    if (!val) {
        /* TODO: We don't support disabling vsx yet */
        return;
    }
    /* Allowable CPUs in spapr_cpu_core.c should already have gotten
     * rid of anything that doesn't do VMX */
    g_assert(env->insns_flags & PPC_ALTIVEC);
    if (!(env->insns_flags2 & PPC2_VSX)) {
        error_setg(errp, "VSX support not available, try cap-vsx=off");
    }
}

static void cap_dfp_apply(sPAPRMachineState *spapr, uint8_t val, Error **errp)
{
    PowerPCCPU *cpu = POWERPC_CPU(first_cpu);
    CPUPPCState *env = &cpu->env;

    if (!val) {
        /* TODO: We don't support disabling dfp yet */
        return;
    }
    if (!(env->insns_flags2 & PPC2_DFP)) {
        error_setg(errp, "DFP support not available, try cap-dfp=off");
    }
}


sPAPRCapabilityInfo capability_table[SPAPR_CAP_NUM] = {
    [SPAPR_CAP_HTM] = {
        .name = "htm",
        .description = "Allow Hardware Transactional Memory (HTM)",
        .index = SPAPR_CAP_HTM,
        .get = spapr_cap_get_bool,
        .set = spapr_cap_set_bool,
        .type = "bool",
        .apply = cap_htm_apply,
    },
    [SPAPR_CAP_VSX] = {
        .name = "vsx",
        .description = "Allow Vector Scalar Extensions (VSX)",
        .index = SPAPR_CAP_VSX,
        .get = spapr_cap_get_bool,
        .set = spapr_cap_set_bool,
        .type = "bool",
        .apply = cap_vsx_apply,
    },
    [SPAPR_CAP_DFP] = {
        .name = "dfp",
        .description = "Allow Decimal Floating Point (DFP)",
        .index = SPAPR_CAP_DFP,
        .get = spapr_cap_get_bool,
        .set = spapr_cap_set_bool,
        .type = "bool",
        .apply = cap_dfp_apply,
    },
};

static sPAPRCapabilities default_caps_with_cpu(sPAPRMachineState *spapr,
                                               CPUState *cs)
{
    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
    PowerPCCPU *cpu = POWERPC_CPU(cs);
    sPAPRCapabilities caps;

    caps = smc->default_caps;

    if (!ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_2_07,
                          0, spapr->max_compat_pvr)) {
        caps.caps[SPAPR_CAP_HTM] = SPAPR_CAP_OFF;
    }

    if (!ppc_check_compat(cpu, CPU_POWERPC_LOGICAL_2_06,
                          0, spapr->max_compat_pvr)) {
        caps.caps[SPAPR_CAP_VSX] = SPAPR_CAP_OFF;
        caps.caps[SPAPR_CAP_DFP] = SPAPR_CAP_OFF;
    }

    return caps;
}

int spapr_caps_pre_load(void *opaque)
{
    sPAPRMachineState *spapr = opaque;

    /* Set to default so we can tell if this came in with the migration */
    spapr->mig = spapr->def;
    return 0;
}

int spapr_caps_pre_save(void *opaque)
{
    sPAPRMachineState *spapr = opaque;

    spapr->mig = spapr->eff;
    return 0;
}

/* This has to be called from the top-level spapr post_load, not the
 * caps specific one.  Otherwise it wouldn't be called when the source
 * caps are all defaults, which could still conflict with overridden
 * caps on the destination */
int spapr_caps_post_migration(sPAPRMachineState *spapr)
{
    int i;
    bool ok = true;
    sPAPRCapabilities dstcaps = spapr->eff;
    sPAPRCapabilities srccaps;

    srccaps = default_caps_with_cpu(spapr, first_cpu);
    for (i = 0; i < SPAPR_CAP_NUM; i++) {
        /* If not default value then assume came in with the migration */
        if (spapr->mig.caps[i] != spapr->def.caps[i]) {
            srccaps.caps[i] = spapr->mig.caps[i];
        }
    }

    for (i = 0; i < SPAPR_CAP_NUM; i++) {
        sPAPRCapabilityInfo *info = &capability_table[i];

        if (srccaps.caps[i] > dstcaps.caps[i]) {
            error_report("cap-%s higher level (%d) in incoming stream than on destination (%d)",
                         info->name, srccaps.caps[i], dstcaps.caps[i]);
            ok = false;
        }

        if (srccaps.caps[i] < dstcaps.caps[i]) {
            warn_report("cap-%s lower level (%d) in incoming stream than on destination (%d)",
                         info->name, srccaps.caps[i], dstcaps.caps[i]);
        }
    }

    return ok ? 0 : -EINVAL;
}

/* Used to generate the migration field and needed function for a spapr cap */
#define SPAPR_CAP_MIG_STATE(cap, ccap)                  \
static bool spapr_cap_##cap##_needed(void *opaque)      \
{                                                       \
    sPAPRMachineState *spapr = opaque;                  \
                                                        \
    return spapr->cmd_line_caps[SPAPR_CAP_##ccap] &&    \
           (spapr->eff.caps[SPAPR_CAP_##ccap] !=        \
            spapr->def.caps[SPAPR_CAP_##ccap]);         \
}                                                       \
                                                        \
const VMStateDescription vmstate_spapr_cap_##cap = {    \
    .name = "spapr/cap/" #cap,                          \
    .version_id = 1,                                    \
    .minimum_version_id = 1,                            \
    .needed = spapr_cap_##cap##_needed,                 \
    .fields = (VMStateField[]) {                        \
        VMSTATE_UINT8(mig.caps[SPAPR_CAP_##ccap],       \
                      sPAPRMachineState),               \
        VMSTATE_END_OF_LIST()                           \
    },                                                  \
}

SPAPR_CAP_MIG_STATE(htm, HTM);
SPAPR_CAP_MIG_STATE(vsx, VSX);
SPAPR_CAP_MIG_STATE(dfp, DFP);

void spapr_caps_reset(sPAPRMachineState *spapr)
{
    sPAPRCapabilities default_caps;
    int i;

    /* First compute the actual set of caps we're running with.. */
    default_caps = default_caps_with_cpu(spapr, first_cpu);

    for (i = 0; i < SPAPR_CAP_NUM; i++) {
        /* Store the defaults */
        spapr->def.caps[i] = default_caps.caps[i];
        /* If not set on the command line then apply the default value */
        if (!spapr->cmd_line_caps[i]) {
            spapr->eff.caps[i] = default_caps.caps[i];
        }
    }

    /* .. then apply those caps to the virtual hardware */

    for (i = 0; i < SPAPR_CAP_NUM; i++) {
        sPAPRCapabilityInfo *info = &capability_table[i];

        /*
         * If the apply function can't set the desired level and thinks it's
         * fatal, it should cause that.
         */
        info->apply(spapr, spapr->eff.caps[i], &error_fatal);
    }
}

void spapr_caps_add_properties(sPAPRMachineClass *smc, Error **errp)
{
    Error *local_err = NULL;
    ObjectClass *klass = OBJECT_CLASS(smc);
    int i;

    for (i = 0; i < ARRAY_SIZE(capability_table); i++) {
        sPAPRCapabilityInfo *cap = &capability_table[i];
        const char *name = g_strdup_printf("cap-%s", cap->name);
        char *desc;

        object_class_property_add(klass, name, cap->type,
                                  cap->get, cap->set,
                                  NULL, cap, &local_err);
        if (local_err) {
            error_propagate(errp, local_err);
            return;
        }

        desc = g_strdup_printf("%s", cap->description);
        object_class_property_set_description(klass, name, desc, &local_err);
        g_free(desc);
        if (local_err) {
            error_propagate(errp, local_err);
            return;
        }
    }
}