Archipelago » qemu

/*

 * QEMU S390x KVM implementation

 *

 * Copyright (c) 2009 Alexander Graf <agraf@suse.de>

 *

 * 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, see <http://www.gnu.org/licenses/>.

 */

#include <sys/types.h>

#include <sys/ioctl.h>

#include <sys/mman.h>

#include <linux/kvm.h>

#include <asm/ptrace.h>

#include "qemu-common.h"

#include "qemu-timer.h"

#include "sysemu.h"

#include "kvm.h"

#include "cpu.h"

#include "device_tree.h"

/* #define DEBUG_KVM */

#ifdef DEBUG_KVM

#define dprintf(fmt, ...) \

    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)

#else

#define dprintf(fmt, ...) \

    do { } while (0)

#endif

#define IPA0_DIAG                       0x8300

#define IPA0_SIGP                       0xae00

#define IPA0_PRIV                       0xb200

#define PRIV_SCLP_CALL                  0x20

#define DIAG_KVM_HYPERCALL              0x500

#define DIAG_KVM_BREAKPOINT             0x501

#define ICPT_INSTRUCTION                0x04

#define ICPT_WAITPSW                    0x1c

#define ICPT_SOFT_INTERCEPT             0x24

#define ICPT_CPU_STOP                   0x28

#define ICPT_IO                         0x40

#define SIGP_RESTART                    0x06

#define SIGP_INITIAL_CPU_RESET          0x0b

#define SIGP_STORE_STATUS_ADDR          0x0e

#define SIGP_SET_ARCH                   0x12

#define SCLP_CMDW_READ_SCP_INFO         0x00020001

#define SCLP_CMDW_READ_SCP_INFO_FORCED  0x00120001

const KVMCapabilityInfo kvm_arch_required_capabilities[] = {

    KVM_CAP_LAST_INFO

};

int kvm_arch_init(KVMState *s)

{

    return 0;

}

int kvm_arch_init_vcpu(CPUS390XState *env)

{

    int ret = 0;

    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL) < 0) {

        perror("cannot init reset vcpu");

    }

    return ret;

}

void kvm_arch_reset_vcpu(CPUS390XState *env)

{

    /* FIXME: add code to reset vcpu. */

}

int kvm_arch_put_registers(CPUS390XState *env, int level)

{

    struct kvm_regs regs;

    int ret;

    int i;

    ret = kvm_vcpu_ioctl(env, KVM_GET_REGS, &regs);

    if (ret < 0) {

        return ret;

    }

    for (i = 0; i < 16; i++) {

        regs.gprs[i] = env->regs[i];

    }

    ret = kvm_vcpu_ioctl(env, KVM_SET_REGS, &regs);

    if (ret < 0) {

        return ret;

    }

    env->kvm_run->psw_addr = env->psw.addr;

    env->kvm_run->psw_mask = env->psw.mask;

    return ret;

}

int kvm_arch_get_registers(CPUS390XState *env)

{

    int ret;

    struct kvm_regs regs;

    int i;

    ret = kvm_vcpu_ioctl(env, KVM_GET_REGS, &regs);

    if (ret < 0) {

        return ret;

    }

    for (i = 0; i < 16; i++) {

        env->regs[i] = regs.gprs[i];

    }

    env->psw.addr = env->kvm_run->psw_addr;

    env->psw.mask = env->kvm_run->psw_mask;

    return 0;

}

/*

 * Legacy layout for s390:

 * Older S390 KVM requires the topmost vma of the RAM to be

 * smaller than an system defined value, which is at least 256GB.

 * Larger systems have larger values. We put the guest between

 * the end of data segment (system break) and this value. We

 * use 32GB as a base to have enough room for the system break

 * to grow. We also have to use MAP parameters that avoid

 * read-only mapping of guest pages.

 */

static void *legacy_s390_alloc(ram_addr_t size)

{

    void *mem;

    mem = mmap((void *) 0x800000000ULL, size,

               PROT_EXEC|PROT_READ|PROT_WRITE,

               MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0);

    if (mem == MAP_FAILED) {

        fprintf(stderr, "Allocating RAM failed\n");

        abort();

    }

    return mem;

}

void *kvm_arch_vmalloc(ram_addr_t size)

{

    /* Can we use the standard allocation ? */

    if (kvm_check_extension(kvm_state, KVM_CAP_S390_GMAP) &&

        kvm_check_extension(kvm_state, KVM_CAP_S390_COW)) {

        return NULL;

    } else {

        return legacy_s390_alloc(size);

    }

}

int kvm_arch_insert_sw_breakpoint(CPUS390XState *env, struct kvm_sw_breakpoint *bp)

{

    static const uint8_t diag_501[] = {0x83, 0x24, 0x05, 0x01};

    if (cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||

        cpu_memory_rw_debug(env, bp->pc, (uint8_t *)diag_501, 4, 1)) {

        return -EINVAL;

    }

    return 0;

}

int kvm_arch_remove_sw_breakpoint(CPUS390XState *env, struct kvm_sw_breakpoint *bp)

{

    uint8_t t[4];

    static const uint8_t diag_501[] = {0x83, 0x24, 0x05, 0x01};

    if (cpu_memory_rw_debug(env, bp->pc, t, 4, 0)) {

        return -EINVAL;

    } else if (memcmp(t, diag_501, 4)) {

        return -EINVAL;

    } else if (cpu_memory_rw_debug(env, bp->pc, (uint8_t *)&bp->saved_insn, 1, 1)) {

        return -EINVAL;

    }

    return 0;

}

void kvm_arch_pre_run(CPUS390XState *env, struct kvm_run *run)

{

}

void kvm_arch_post_run(CPUS390XState *env, struct kvm_run *run)

{

}

int kvm_arch_process_async_events(CPUS390XState *env)

{

    return env->halted;

}

void kvm_s390_interrupt_internal(CPUS390XState *env, int type, uint32_t parm,

                                 uint64_t parm64, int vm)

{

    struct kvm_s390_interrupt kvmint;

    int r;

    if (!env->kvm_state) {

        return;

    }

    kvmint.type = type;

    kvmint.parm = parm;

    kvmint.parm64 = parm64;

    if (vm) {

        r = kvm_vm_ioctl(env->kvm_state, KVM_S390_INTERRUPT, &kvmint);

    } else {

        r = kvm_vcpu_ioctl(env, KVM_S390_INTERRUPT, &kvmint);

    }

    if (r < 0) {

        fprintf(stderr, "KVM failed to inject interrupt\n");

        exit(1);

    }

}

void kvm_s390_virtio_irq(CPUS390XState *env, int config_change, uint64_t token)

{

    kvm_s390_interrupt_internal(env, KVM_S390_INT_VIRTIO, config_change,

                                token, 1);

}

void kvm_s390_interrupt(CPUS390XState *env, int type, uint32_t code)

{

    kvm_s390_interrupt_internal(env, type, code, 0, 0);

}

static void enter_pgmcheck(CPUS390XState *env, uint16_t code)

{

    kvm_s390_interrupt(env, KVM_S390_PROGRAM_INT, code);

}

static inline void setcc(CPUS390XState *env, uint64_t cc)

{

    env->kvm_run->psw_mask &= ~(3ull << 44);

    env->kvm_run->psw_mask |= (cc & 3) << 44;

    env->psw.mask &= ~(3ul << 44);

    env->psw.mask |= (cc & 3) << 44;

}

static int kvm_sclp_service_call(CPUS390XState *env, struct kvm_run *run,

                                 uint16_t ipbh0)

{

    uint32_t sccb;

    uint64_t code;

    int r = 0;

    cpu_synchronize_state(env);

    sccb = env->regs[ipbh0 & 0xf];

    code = env->regs[(ipbh0 & 0xf0) >> 4];

    r = sclp_service_call(env, sccb, code);

    if (r < 0) {

        enter_pgmcheck(env, -r);

    }

    setcc(env, r);

    return 0;

}

static int handle_priv(CPUS390XState *env, struct kvm_run *run, uint8_t ipa1)

{

    int r = 0;

    uint16_t ipbh0 = (run->s390_sieic.ipb & 0xffff0000) >> 16;

    dprintf("KVM: PRIV: %d\n", ipa1);

    switch (ipa1) {

        case PRIV_SCLP_CALL:

            r = kvm_sclp_service_call(env, run, ipbh0);

            break;

        default:

            dprintf("KVM: unknown PRIV: 0x%x\n", ipa1);

            r = -1;

            break;

    }

    return r;

}

static int handle_hypercall(CPUS390XState *env, struct kvm_run *run)

{

    cpu_synchronize_state(env);

    env->regs[2] = s390_virtio_hypercall(env, env->regs[2], env->regs[1]);

    return 0;

}

static int handle_diag(CPUS390XState *env, struct kvm_run *run, int ipb_code)

{

    int r = 0;

    switch (ipb_code) {

        case DIAG_KVM_HYPERCALL:

            r = handle_hypercall(env, run);

            break;

        case DIAG_KVM_BREAKPOINT:

            sleep(10);

            break;

        default:

            dprintf("KVM: unknown DIAG: 0x%x\n", ipb_code);

            r = -1;

            break;

    }

    return r;

}

static int s390_cpu_restart(S390CPU *cpu)

{

    CPUS390XState *env = &cpu->env;

    kvm_s390_interrupt(env, KVM_S390_RESTART, 0);

    s390_add_running_cpu(env);

    qemu_cpu_kick(env);

    dprintf("DONE: SIGP cpu restart: %p\n", env);

    return 0;

}

static int s390_store_status(CPUS390XState *env, uint32_t parameter)

{

    /* XXX */

    fprintf(stderr, "XXX SIGP store status\n");

    return -1;

}

static int s390_cpu_initial_reset(CPUS390XState *env)

{

    int i;

    s390_del_running_cpu(env);

    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL) < 0) {

        perror("cannot init reset vcpu");

    }

    /* Manually zero out all registers */

    cpu_synchronize_state(env);

    for (i = 0; i < 16; i++) {

        env->regs[i] = 0;

    }

    dprintf("DONE: SIGP initial reset: %p\n", env);

    return 0;

}

static int handle_sigp(CPUS390XState *env, struct kvm_run *run, uint8_t ipa1)

{

    uint8_t order_code;

    uint32_t parameter;

    uint16_t cpu_addr;

    uint8_t t;

    int r = -1;

    S390CPU *target_cpu;

    CPUS390XState *target_env;

    cpu_synchronize_state(env);

    /* get order code */

    order_code = run->s390_sieic.ipb >> 28;

    if (order_code > 0) {

        order_code = env->regs[order_code];

    }

    order_code += (run->s390_sieic.ipb & 0x0fff0000) >> 16;

    /* get parameters */

    t = (ipa1 & 0xf0) >> 4;

    if (!(t % 2)) {

        t++;

    }

    parameter = env->regs[t] & 0x7ffffe00;

    cpu_addr = env->regs[ipa1 & 0x0f];

    target_cpu = s390_cpu_addr2state(cpu_addr);

    if (target_cpu == NULL) {

        goto out;

    }

    target_env = &target_cpu->env;

    switch (order_code) {

        case SIGP_RESTART:

            r = s390_cpu_restart(target_cpu);

            break;

        case SIGP_STORE_STATUS_ADDR:

            r = s390_store_status(target_env, parameter);

            break;

        case SIGP_SET_ARCH:

            /* make the caller panic */

            return -1;

        case SIGP_INITIAL_CPU_RESET:

            r = s390_cpu_initial_reset(target_env);

            break;

        default:

            fprintf(stderr, "KVM: unknown SIGP: 0x%x\n", order_code);

            break;

    }

out:

    setcc(env, r ? 3 : 0);

    return 0;

}

static int handle_instruction(CPUS390XState *env, struct kvm_run *run)

{

    unsigned int ipa0 = (run->s390_sieic.ipa & 0xff00);

    uint8_t ipa1 = run->s390_sieic.ipa & 0x00ff;

    int ipb_code = (run->s390_sieic.ipb & 0x0fff0000) >> 16;

    int r = -1;

    dprintf("handle_instruction 0x%x 0x%x\n", run->s390_sieic.ipa, run->s390_sieic.ipb);

    switch (ipa0) {

        case IPA0_PRIV:

            r = handle_priv(env, run, ipa1);

            break;

        case IPA0_DIAG:

            r = handle_diag(env, run, ipb_code);

            break;

        case IPA0_SIGP:

            r = handle_sigp(env, run, ipa1);

            break;

    }

    if (r < 0) {

        enter_pgmcheck(env, 0x0001);

    }

    return 0;

}

static bool is_special_wait_psw(CPUS390XState *env)

{

    /* signal quiesce */

    return env->kvm_run->psw_addr == 0xfffUL;

}

static int handle_intercept(CPUS390XState *env)

{

    struct kvm_run *run = env->kvm_run;

    int icpt_code = run->s390_sieic.icptcode;

    int r = 0;

    dprintf("intercept: 0x%x (at 0x%lx)\n", icpt_code,

            (long)env->kvm_run->psw_addr);

    switch (icpt_code) {

        case ICPT_INSTRUCTION:

            r = handle_instruction(env, run);

            break;

        case ICPT_WAITPSW:

            if (s390_del_running_cpu(env) == 0 &&

                is_special_wait_psw(env)) {

                qemu_system_shutdown_request();

            }

            r = EXCP_HALTED;

            break;

        case ICPT_CPU_STOP:

            if (s390_del_running_cpu(env) == 0) {

                qemu_system_shutdown_request();

            }

            r = EXCP_HALTED;

            break;

        case ICPT_SOFT_INTERCEPT:

            fprintf(stderr, "KVM unimplemented icpt SOFT\n");

            exit(1);

            break;

        case ICPT_IO:

            fprintf(stderr, "KVM unimplemented icpt IO\n");

            exit(1);

            break;

        default:

            fprintf(stderr, "Unknown intercept code: %d\n", icpt_code);

            exit(1);

            break;

    }

    return r;

}

int kvm_arch_handle_exit(CPUS390XState *env, struct kvm_run *run)

{

    int ret = 0;

    switch (run->exit_reason) {

        case KVM_EXIT_S390_SIEIC:

            ret = handle_intercept(env);

            break;

        case KVM_EXIT_S390_RESET:

            qemu_system_reset_request();

            break;

        default:

            fprintf(stderr, "Unknown KVM exit: %d\n", run->exit_reason);

            break;

    }

    if (ret == 0) {

        ret = EXCP_INTERRUPT;

    }

    return ret;

}

bool kvm_arch_stop_on_emulation_error(CPUS390XState *env)

{

    return true;

}

int kvm_arch_on_sigbus_vcpu(CPUS390XState *env, int code, void *addr)

{

    return 1;

}

int kvm_arch_on_sigbus(int code, void *addr)

{

    return 1;

}