s390x: helper functions for system emulation

When running system emulation, we need to transverse through the MMU and
deliver interrupts according to the specification.

This patch implements those two pieces and in addition adjusts the CPU
initialization code to account for the new fields in CPUState.

Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 555 insertions, 10 deletions

diff --git a/target-s390x/helper.c b/target-s390x/helper.c
index 629dfd9708..c79af46693 100644
--- a/target-s390x/helper.c
+++ b/target-s390x/helper.c
@@ -2,6 +2,7 @@
  *  S/390 helpers
  *
  *  Copyright (c) 2009 Ulrich Hecht
+ *  Copyright (c) 2011 Alexander Graf
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -25,27 +26,107 @@
 #include "exec-all.h"
 #include "gdbstub.h"
 #include "qemu-common.h"
+#include "qemu-timer.h"
 
+#if !defined(CONFIG_USER_ONLY)
 #include <linux/kvm.h>
 #include "kvm.h"
+#endif
+
+//#define DEBUG_S390
+//#define DEBUG_S390_PTE
+//#define DEBUG_S390_STDOUT
+
+#ifdef DEBUG_S390
+#ifdef DEBUG_S390_STDOUT
+#define DPRINTF(fmt, ...) \
+    do { fprintf(stderr, fmt, ## __VA_ARGS__); \
+         qemu_log(fmt, ##__VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+    do { qemu_log(fmt, ## __VA_ARGS__); } while (0)
+#endif
+#else
+#define DPRINTF(fmt, ...) \
+    do { } while (0)
+#endif
+
+#ifdef DEBUG_S390_PTE
+#define PTE_DPRINTF DPRINTF
+#else
+#define PTE_DPRINTF(fmt, ...) \
+    do { } while (0)
+#endif
+
+#ifndef CONFIG_USER_ONLY
+static void s390x_tod_timer(void *opaque)
+{
+    CPUState *env = opaque;
+
+    env->pending_int |= INTERRUPT_TOD;
+    cpu_interrupt(env, CPU_INTERRUPT_HARD);
+}
+
+static void s390x_cpu_timer(void *opaque)
+{
+    CPUState *env = opaque;
+
+    env->pending_int |= INTERRUPT_CPUTIMER;
+    cpu_interrupt(env, CPU_INTERRUPT_HARD);
+}
+#endif
 
 CPUS390XState *cpu_s390x_init(const char *cpu_model)
 {
     CPUS390XState *env;
+#if !defined (CONFIG_USER_ONLY)
+    struct tm tm;
+#endif
     static int inited = 0;
+    static int cpu_num = 0;
 
     env = qemu_mallocz(sizeof(CPUS390XState));
     cpu_exec_init(env);
     if (!inited) {
         inited = 1;
+        s390x_translate_init();
     }
 
+#if !defined(CONFIG_USER_ONLY)
+    qemu_get_timedate(&tm, 0);
+    env->tod_offset = TOD_UNIX_EPOCH +
+                      (time2tod(mktimegm(&tm)) * 1000000000ULL);
+    env->tod_basetime = 0;
+    env->tod_timer = qemu_new_timer_ns(vm_clock, s390x_tod_timer, env);
+    env->cpu_timer = qemu_new_timer_ns(vm_clock, s390x_cpu_timer, env);
+#endif
     env->cpu_model_str = cpu_model;
+    env->cpu_num = cpu_num++;
+    env->ext_index = -1;
     cpu_reset(env);
     qemu_init_vcpu(env);
     return env;
 }
 
+#if defined(CONFIG_USER_ONLY)
+
+void do_interrupt (CPUState *env)
+{
+    env->exception_index = -1;
+}
+
+int cpu_s390x_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
+                              int mmu_idx, int is_softmmu)
+{
+    /* fprintf(stderr,"%s: address 0x%lx rw %d mmu_idx %d is_softmmu %d\n",
+            __FUNCTION__, address, rw, mmu_idx, is_softmmu); */
+    env->exception_index = EXCP_ADDR;
+    env->__excp_addr = address; /* FIXME: find out how this works on a real machine */
+    return 1;
+}
+
+#endif /* CONFIG_USER_ONLY */
+
 void cpu_reset(CPUS390XState *env)
 {
     if (qemu_loglevel_mask(CPU_LOG_RESET)) {
@@ -58,31 +139,495 @@ void cpu_reset(CPUS390XState *env)
     tlb_flush(env, 1);
 }
 
-target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
+#ifndef CONFIG_USER_ONLY
+
+/* Ensure to exit the TB after this call! */
+static void trigger_pgm_exception(CPUState *env, uint32_t code, uint32_t ilc)
+{
+    env->exception_index = EXCP_PGM;
+    env->int_pgm_code = code;
+    env->int_pgm_ilc = ilc;
+}
+
+static int trans_bits(CPUState *env, uint64_t mode)
+{
+    int bits = 0;
+
+    switch (mode) {
+    case PSW_ASC_PRIMARY:
+        bits = 1;
+        break;
+    case PSW_ASC_SECONDARY:
+        bits = 2;
+        break;
+    case PSW_ASC_HOME:
+        bits = 3;
+        break;
+    default:
+        cpu_abort(env, "unknown asc mode\n");
+        break;
+    }
+
+    return bits;
+}
+
+static void trigger_prot_fault(CPUState *env, target_ulong vaddr, uint64_t mode)
+{
+    int ilc = ILC_LATER_INC_2;
+    int bits = trans_bits(env, mode) | 4;
+
+    DPRINTF("%s: vaddr=%016" PRIx64 " bits=%d\n", __FUNCTION__, vaddr, bits);
+
+    stq_phys(env->psa + offsetof(LowCore, trans_exc_code), vaddr | bits);
+    trigger_pgm_exception(env, PGM_PROTECTION, ilc);
+}
+
+static void trigger_page_fault(CPUState *env, target_ulong vaddr, uint32_t type,
+                               uint64_t asc, int rw)
+{
+    int ilc = ILC_LATER;
+    int bits = trans_bits(env, asc);
+
+    if (rw == 2) {
+        /* code has is undefined ilc */
+        ilc = 2;
+    }
+
+    DPRINTF("%s: vaddr=%016" PRIx64 " bits=%d\n", __FUNCTION__, vaddr, bits);
+
+    stq_phys(env->psa + offsetof(LowCore, trans_exc_code), vaddr | bits);
+    trigger_pgm_exception(env, type, ilc);
+}
+
+static int mmu_translate_asce(CPUState *env, target_ulong vaddr, uint64_t asc,
+                              uint64_t asce, int level, target_ulong *raddr,
+                              int *flags, int rw)
 {
+    uint64_t offs = 0;
+    uint64_t origin;
+    uint64_t new_asce;
+
+    PTE_DPRINTF("%s: 0x%" PRIx64 "\n", __FUNCTION__, asce);
+
+    if (((level != _ASCE_TYPE_SEGMENT) && (asce & _REGION_ENTRY_INV)) ||
+        ((level == _ASCE_TYPE_SEGMENT) && (asce & _SEGMENT_ENTRY_INV))) {
+        /* XXX different regions have different faults */
+        DPRINTF("%s: invalid region\n", __FUNCTION__);
+        trigger_page_fault(env, vaddr, PGM_SEGMENT_TRANS, asc, rw);
+        return -1;
+    }
+
+    if ((level <= _ASCE_TYPE_MASK) && ((asce & _ASCE_TYPE_MASK) != level)) {
+        trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw);
+        return -1;
+    }
+
+    if (asce & _ASCE_REAL_SPACE) {
+        /* direct mapping */
+
+        *raddr = vaddr;
+        return 0;
+    }
+
+    origin = asce & _ASCE_ORIGIN;
+
+    switch (level) {
+    case _ASCE_TYPE_REGION1 + 4:
+        offs = (vaddr >> 50) & 0x3ff8;
+        break;
+    case _ASCE_TYPE_REGION1:
+        offs = (vaddr >> 39) & 0x3ff8;
+        break;
+    case _ASCE_TYPE_REGION2:
+        offs = (vaddr >> 28) & 0x3ff8;
+        break;
+    case _ASCE_TYPE_REGION3:
+        offs = (vaddr >> 17) & 0x3ff8;
+        break;
+    case _ASCE_TYPE_SEGMENT:
+        offs = (vaddr >> 9) & 0x07f8;
+        origin = asce & _SEGMENT_ENTRY_ORIGIN;
+        break;
+    }
+
+    /* XXX region protection flags */
+    /* *flags &= ~PAGE_WRITE */
+
+    new_asce = ldq_phys(origin + offs);
+    PTE_DPRINTF("%s: 0x%" PRIx64 " + 0x%" PRIx64 " => 0x%016" PRIx64 "\n",
+                __FUNCTION__, origin, offs, new_asce);
+
+    if (level != _ASCE_TYPE_SEGMENT) {
+        /* yet another region */
+        return mmu_translate_asce(env, vaddr, asc, new_asce, level - 4, raddr,
+                                  flags, rw);
+    }
+
+    /* PTE */
+    if (new_asce & _PAGE_INVALID) {
+        DPRINTF("%s: PTE=0x%" PRIx64 " invalid\n", __FUNCTION__, new_asce);
+        trigger_page_fault(env, vaddr, PGM_PAGE_TRANS, asc, rw);
+        return -1;
+    }
+
+    if (new_asce & _PAGE_RO) {
+        *flags &= ~PAGE_WRITE;
+    }
+
+    *raddr = new_asce & _ASCE_ORIGIN;
+
+    PTE_DPRINTF("%s: PTE=0x%" PRIx64 "\n", __FUNCTION__, new_asce);
+
     return 0;
 }
 
-#ifndef CONFIG_USER_ONLY
+static int mmu_translate_asc(CPUState *env, target_ulong vaddr, uint64_t asc,
+                             target_ulong *raddr, int *flags, int rw)
+{
+    uint64_t asce = 0;
+    int level, new_level;
+    int r;
 
-int cpu_s390x_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
+    switch (asc) {
+    case PSW_ASC_PRIMARY:
+        PTE_DPRINTF("%s: asc=primary\n", __FUNCTION__);
+        asce = env->cregs[1];
+        break;
+    case PSW_ASC_SECONDARY:
+        PTE_DPRINTF("%s: asc=secondary\n", __FUNCTION__);
+        asce = env->cregs[7];
+        break;
+    case PSW_ASC_HOME:
+        PTE_DPRINTF("%s: asc=home\n", __FUNCTION__);
+        asce = env->cregs[13];
+        break;
+    }
+
+    switch (asce & _ASCE_TYPE_MASK) {
+    case _ASCE_TYPE_REGION1:
+        break;
+    case _ASCE_TYPE_REGION2:
+        if (vaddr & 0xffe0000000000000ULL) {
+            DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64
+                        " 0xffe0000000000000ULL\n", __FUNCTION__,
+                        vaddr);
+            trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw);
+            return -1;
+        }
+        break;
+    case _ASCE_TYPE_REGION3:
+        if (vaddr & 0xfffffc0000000000ULL) {
+            DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64
+                        " 0xfffffc0000000000ULL\n", __FUNCTION__,
+                        vaddr);
+            trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw);
+            return -1;
+        }
+        break;
+    case _ASCE_TYPE_SEGMENT:
+        if (vaddr & 0xffffffff80000000ULL) {
+            DPRINTF("%s: vaddr doesn't fit 0x%16" PRIx64
+                        " 0xffffffff80000000ULL\n", __FUNCTION__,
+                        vaddr);
+            trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw);
+            return -1;
+        }
+        break;
+    }
+
+    /* fake level above current */
+    level = asce & _ASCE_TYPE_MASK;
+    new_level = level + 4;
+    asce = (asce & ~_ASCE_TYPE_MASK) | (new_level & _ASCE_TYPE_MASK);
+
+    r = mmu_translate_asce(env, vaddr, asc, asce, new_level, raddr, flags, rw);
+
+    if ((rw == 1) && !(*flags & PAGE_WRITE)) {
+        trigger_prot_fault(env, vaddr, asc);
+        return -1;
+    }
+
+    return r;
+}
+
+int mmu_translate(CPUState *env, target_ulong vaddr, int rw, uint64_t asc,
+                  target_ulong *raddr, int *flags)
+{
+    int r = -1;
+
+    *flags = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+    vaddr &= TARGET_PAGE_MASK;
+
+    if (!(env->psw.mask & PSW_MASK_DAT)) {
+        *raddr = vaddr;
+        r = 0;
+        goto out;
+    }
+
+    switch (asc) {
+    case PSW_ASC_PRIMARY:
+    case PSW_ASC_HOME:
+        r = mmu_translate_asc(env, vaddr, asc, raddr, flags, rw);
+        break;
+    case PSW_ASC_SECONDARY:
+        /*
+         * Instruction: Primary
+         * Data: Secondary
+         */
+        if (rw == 2) {
+            r = mmu_translate_asc(env, vaddr, PSW_ASC_PRIMARY, raddr, flags,
+                                  rw);
+            *flags &= ~(PAGE_READ | PAGE_WRITE);
+        } else {
+            r = mmu_translate_asc(env, vaddr, PSW_ASC_SECONDARY, raddr, flags,
+                                  rw);
+            *flags &= ~(PAGE_EXEC);
+        }
+        break;
+    case PSW_ASC_ACCREG:
+    default:
+        hw_error("guest switched to unknown asc mode\n");
+        break;
+    }
+
+out:
+    /* Convert real address -> absolute address */
+    if (*raddr < 0x2000) {
+        *raddr = *raddr + env->psa;
+    }
+
+    return r;
+}
+
+int cpu_s390x_handle_mmu_fault (CPUState *env, target_ulong _vaddr, int rw,
                                 int mmu_idx, int is_softmmu)
 {
-    target_ulong phys;
+    uint64_t asc = env->psw.mask & PSW_MASK_ASC;
+    target_ulong vaddr, raddr;
     int prot;
 
-    /* XXX: implement mmu */
+    DPRINTF("%s: address 0x%" PRIx64 " rw %d mmu_idx %d is_softmmu %d\n",
+            __FUNCTION__, _vaddr, rw, mmu_idx, is_softmmu);
+
+    _vaddr &= TARGET_PAGE_MASK;
+    vaddr = _vaddr;
+
+    /* 31-Bit mode */
+    if (!(env->psw.mask & PSW_MASK_64)) {
+        vaddr &= 0x7fffffff;
+    }
+
+    if (mmu_translate(env, vaddr, rw, asc, &raddr, &prot)) {
+        /* Translation ended in exception */
+        return 1;
+    }
 
-    phys = address;
-    prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+    /* check out of RAM access */
+    if (raddr > (ram_size + virtio_size)) {
+        DPRINTF("%s: aaddr %" PRIx64 " > ram_size %" PRIx64 "\n", __FUNCTION__,
+                (uint64_t)aaddr, (uint64_t)ram_size);
+        trigger_pgm_exception(env, PGM_ADDRESSING, ILC_LATER);
+        return 1;
+    }
 
-    tlb_set_page(env, address & TARGET_PAGE_MASK,
-                 phys & TARGET_PAGE_MASK, prot,
+    DPRINTF("%s: set tlb %" PRIx64 " -> %" PRIx64 " (%x)\n", __FUNCTION__,
+            (uint64_t)vaddr, (uint64_t)raddr, prot);
+
+    tlb_set_page(env, _vaddr, raddr, prot,
                  mmu_idx, TARGET_PAGE_SIZE);
+
     return 0;
 }
-#endif /* CONFIG_USER_ONLY */
+
+target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong vaddr)
+{
+    target_ulong raddr;
+    int prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+    int old_exc = env->exception_index;
+    uint64_t asc = env->psw.mask & PSW_MASK_ASC;
+
+    /* 31-Bit mode */
+    if (!(env->psw.mask & PSW_MASK_64)) {
+        vaddr &= 0x7fffffff;
+    }
+
+    mmu_translate(env, vaddr, 2, asc, &raddr, &prot);
+    env->exception_index = old_exc;
+
+    return raddr;
+}
+
+void load_psw(CPUState *env, uint64_t mask, uint64_t addr)
+{
+    if (mask & PSW_MASK_WAIT) {
+        env->halted = 1;
+        env->exception_index = EXCP_HLT;
+        if (!(mask & (PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK))) {
+            /* XXX disabled wait state - CPU is dead */
+        }
+    }
+
+    env->psw.addr = addr;
+    env->psw.mask = mask;
+    env->cc_op = (mask >> 13) & 3;
+}
+
+static uint64_t get_psw_mask(CPUState *env)
+{
+    uint64_t r = env->psw.mask;
+
+    env->cc_op = calc_cc(env, env->cc_op, env->cc_src, env->cc_dst, env->cc_vr);
+
+    r &= ~(3ULL << 13);
+    assert(!(env->cc_op & ~3));
+    r |= env->cc_op << 13;
+
+    return r;
+}
+
+static void do_svc_interrupt(CPUState *env)
+{
+    uint64_t mask, addr;
+    LowCore *lowcore;
+    target_phys_addr_t len = TARGET_PAGE_SIZE;
+
+    lowcore = cpu_physical_memory_map(env->psa, &len, 1);
+
+    lowcore->svc_code = cpu_to_be16(env->int_svc_code);
+    lowcore->svc_ilc = cpu_to_be16(env->int_svc_ilc);
+    lowcore->svc_old_psw.mask = cpu_to_be64(get_psw_mask(env));
+    lowcore->svc_old_psw.addr = cpu_to_be64(env->psw.addr + (env->int_svc_ilc));
+    mask = be64_to_cpu(lowcore->svc_new_psw.mask);
+    addr = be64_to_cpu(lowcore->svc_new_psw.addr);
+
+    cpu_physical_memory_unmap(lowcore, len, 1, len);
+
+    load_psw(env, mask, addr);
+}
+
+static void do_program_interrupt(CPUState *env)
+{
+    uint64_t mask, addr;
+    LowCore *lowcore;
+    target_phys_addr_t len = TARGET_PAGE_SIZE;
+    int ilc = env->int_pgm_ilc;
+
+    switch (ilc) {
+    case ILC_LATER:
+        ilc = get_ilc(ldub_code(env->psw.addr));
+        break;
+    case ILC_LATER_INC:
+        ilc = get_ilc(ldub_code(env->psw.addr));
+        env->psw.addr += ilc * 2;
+        break;
+    case ILC_LATER_INC_2:
+        ilc = get_ilc(ldub_code(env->psw.addr)) * 2;
+        env->psw.addr += ilc;
+        break;
+    }
+
+    qemu_log("%s: code=0x%x ilc=%d\n", __FUNCTION__, env->int_pgm_code, ilc);
+
+    lowcore = cpu_physical_memory_map(env->psa, &len, 1);
+
+    lowcore->pgm_ilc = cpu_to_be16(ilc);
+    lowcore->pgm_code = cpu_to_be16(env->int_pgm_code);
+    lowcore->program_old_psw.mask = cpu_to_be64(get_psw_mask(env));
+    lowcore->program_old_psw.addr = cpu_to_be64(env->psw.addr);
+    mask = be64_to_cpu(lowcore->program_new_psw.mask);
+    addr = be64_to_cpu(lowcore->program_new_psw.addr);
+
+    cpu_physical_memory_unmap(lowcore, len, 1, len);
+
+    DPRINTF("%s: %x %x %" PRIx64 " %" PRIx64 "\n", __FUNCTION__,
+            env->int_pgm_code, ilc, env->psw.mask,
+            env->psw.addr);
+
+    load_psw(env, mask, addr);
+}
+
+#define VIRTIO_SUBCODE_64 0x0D00
+
+static void do_ext_interrupt(CPUState *env)
+{
+    uint64_t mask, addr;
+    LowCore *lowcore;
+    target_phys_addr_t len = TARGET_PAGE_SIZE;
+    ExtQueue *q;
+
+    if (!(env->psw.mask & PSW_MASK_EXT)) {
+        cpu_abort(env, "Ext int w/o ext mask\n");
+    }
+
+    if (env->ext_index < 0 || env->ext_index > MAX_EXT_QUEUE) {
+        cpu_abort(env, "Ext queue overrun: %d\n", env->ext_index);
+    }
+
+    q = &env->ext_queue[env->ext_index];
+    lowcore = cpu_physical_memory_map(env->psa, &len, 1);
+
+    lowcore->ext_int_code = cpu_to_be16(q->code);
+    lowcore->ext_params = cpu_to_be32(q->param);
+    lowcore->ext_params2 = cpu_to_be64(q->param64);
+    lowcore->external_old_psw.mask = cpu_to_be64(get_psw_mask(env));
+    lowcore->external_old_psw.addr = cpu_to_be64(env->psw.addr);
+    lowcore->cpu_addr = cpu_to_be16(env->cpu_num | VIRTIO_SUBCODE_64);
+    mask = be64_to_cpu(lowcore->external_new_psw.mask);
+    addr = be64_to_cpu(lowcore->external_new_psw.addr);
+
+    cpu_physical_memory_unmap(lowcore, len, 1, len);
+
+    env->ext_index--;
+    if (env->ext_index == -1) {
+        env->pending_int &= ~INTERRUPT_EXT;
+    }
+
+    DPRINTF("%s: %" PRIx64 " %" PRIx64 "\n", __FUNCTION__,
+            env->psw.mask, env->psw.addr);
+
+    load_psw(env, mask, addr);
+}
 
 void do_interrupt (CPUState *env)
 {
+    qemu_log("%s: %d at pc=%" PRIx64 "\n", __FUNCTION__, env->exception_index,
+             env->psw.addr);
+
+    /* handle external interrupts */
+    if ((env->psw.mask & PSW_MASK_EXT) &&
+        env->exception_index == -1) {
+        if (env->pending_int & INTERRUPT_EXT) {
+            /* code is already in env */
+            env->exception_index = EXCP_EXT;
+        } else if (env->pending_int & INTERRUPT_TOD) {
+            cpu_inject_ext(env, 0x1004, 0, 0);
+            env->exception_index = EXCP_EXT;
+            env->pending_int &= ~INTERRUPT_EXT;
+            env->pending_int &= ~INTERRUPT_TOD;
+        } else if (env->pending_int & INTERRUPT_CPUTIMER) {
+            cpu_inject_ext(env, 0x1005, 0, 0);
+            env->exception_index = EXCP_EXT;
+            env->pending_int &= ~INTERRUPT_EXT;
+            env->pending_int &= ~INTERRUPT_TOD;
+        }
+    }
+
+    switch (env->exception_index) {
+    case EXCP_PGM:
+        do_program_interrupt(env);
+        break;
+    case EXCP_SVC:
+        do_svc_interrupt(env);
+        break;
+    case EXCP_EXT:
+        do_ext_interrupt(env);
+        break;
+    }
+    env->exception_index = -1;
+
+    if (!env->pending_int) {
+        env->interrupt_request &= ~CPU_INTERRUPT_HARD;
+    }
 }
+
+#endif /* CONFIG_USER_ONLY */