S/390 CPU fake emulation

Because Qemu currently requires a TCG target to exist and there are quite some
useful helpers here to lay the groundwork for out KVM target, let's create a
stub TCG emulation target for S390X CPUs.

This is required to make tcg happy. The emulation target itself won't work
though.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

cpu-exec.c

@@ -249,6 +249,7 @@ int cpu_exec(CPUState *env1)
 #elif defined(TARGET_MIPS)
 #elif defined(TARGET_SH4)
 #elif defined(TARGET_CRIS)
+#elif defined(TARGET_S390X)
     /* XXXXX */
 #else
 #error unsupported target CPU
@@ -673,6 +674,7 @@ int cpu_exec(CPUState *env1)
 #elif defined(TARGET_SH4)
 #elif defined(TARGET_ALPHA)
 #elif defined(TARGET_CRIS)
+#elif defined(TARGET_S390X)
     /* XXXXX */
 #else
 #error unsupported target CPU

target-s390x/cpu.h

@@ -0,0 +1,122 @@
+/*
+ * S/390 virtual CPU header
+ *
+ *  Copyright (c) 2009 Ulrich Hecht
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
+ */
+#ifndef CPU_S390X_H
+#define CPU_S390X_H
+
+#define TARGET_LONG_BITS 64
+
+#define ELF_MACHINE	EM_S390
+
+#define CPUState struct CPUS390XState
+
+#include "cpu-defs.h"
+
+#include "softfloat.h"
+
+#define NB_MMU_MODES 2 // guess
+#define MMU_USER_IDX 0 // guess
+
+typedef union FPReg {
+    struct {
+#ifdef WORDS_BIGENDIAN
+        float32 e;
+        int32_t __pad;
+#else
+        int32_t __pad;
+        float32 e;
+#endif
+    };
+    float64 d;
+    uint64_t i;
+} FPReg;
+
+typedef struct CPUS390XState {
+    uint64_t regs[16];	/* GP registers */
+
+    uint32_t aregs[16];	/* access registers */
+
+    uint32_t fpc;	/* floating-point control register */
+    FPReg fregs[16]; /* FP registers */
+    float_status fpu_status; /* passed to softfloat lib */
+
+    struct {
+        uint64_t mask;
+        uint64_t addr;
+    } psw;
+
+    int cc; /* condition code (0-3) */
+
+    uint64_t __excp_addr;
+
+    CPU_COMMON
+} CPUS390XState;
+
+#if defined(CONFIG_USER_ONLY)
+static inline void cpu_clone_regs(CPUState *env, target_ulong newsp)
+{
+    if (newsp)
+        env->regs[15] = newsp;
+    env->regs[0] = 0;
+}
+#endif
+
+CPUS390XState *cpu_s390x_init(const char *cpu_model);
+int cpu_s390x_exec(CPUS390XState *s);
+void cpu_s390x_close(CPUS390XState *s);
+
+/* you can call this signal handler from your SIGBUS and SIGSEGV
+   signal handlers to inform the virtual CPU of exceptions. non zero
+   is returned if the signal was handled by the virtual CPU.  */
+int cpu_s390x_signal_handler(int host_signum, void *pinfo,
+                           void *puc);
+int cpu_s390x_handle_mmu_fault (CPUS390XState *env, target_ulong address, int rw,
+                              int mmu_idx, int is_softmuu);
+#define cpu_handle_mmu_fault cpu_s390x_handle_mmu_fault
+
+#define TARGET_PAGE_BITS 12
+
+#define cpu_init cpu_s390x_init
+#define cpu_exec cpu_s390x_exec
+#define cpu_gen_code cpu_s390x_gen_code
+
+#include "cpu-all.h"
+#include "exec-all.h"
+
+#define EXCP_OPEX 1 /* operation exception (sigill) */
+#define EXCP_SVC 2 /* supervisor call (syscall) */
+#define EXCP_ADDR 5 /* addressing exception */
+#define EXCP_EXECUTE_SVC 0xff00000 /* supervisor call via execute insn */
+
+static inline void cpu_pc_from_tb(CPUState *env, TranslationBlock* tb)
+{
+    env->psw.addr = tb->pc;
+}
+
+static inline void cpu_get_tb_cpu_state(CPUState* env, target_ulong *pc,
+                                        target_ulong *cs_base, int *flags)
+{
+    *pc = env->psw.addr;
+    /* XXX this is correct for user-mode emulation, but needs
+     *     the asce register information as well when softmmu
+     *     is implemented in the future */
+    *cs_base = 0;
+    *flags = env->psw.mask;
+}
+#endif

target-s390x/exec.h

@@ -0,0 +1,51 @@
+/*
+ *  S/390 execution defines
+ *
+ *  Copyright (c) 2009 Ulrich Hecht
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
+ */
+
+#include "dyngen-exec.h"
+
+register struct CPUS390XState *env asm(AREG0);
+
+#include "cpu.h"
+#include "exec-all.h"
+
+static inline int cpu_has_work(CPUState *env)
+{
+    return env->interrupt_request & CPU_INTERRUPT_HARD; // guess
+}
+
+static inline void regs_to_env(void)
+{
+}
+
+static inline void env_to_regs(void)
+{
+}
+
+static inline int cpu_halted(CPUState *env)
+{
+    if (!env->halted) {
+       return 0;
+    }
+    if (cpu_has_work(env)) {
+        env->halted = 0;
+        return 0;
+    }
+    return EXCP_HALTED;
+}

target-s390x/helper.c

@@ -0,0 +1,62 @@
+/*
+ *  S/390 helpers
+ *
+ *  Copyright (c) 2009 Ulrich Hecht
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "cpu.h"
+#include "exec-all.h"
+#include "gdbstub.h"
+#include "qemu-common.h"
+
+CPUS390XState *cpu_s390x_init(const char *cpu_model)
+{
+    CPUS390XState *env;
+    static int inited = 0;
+
+    env = qemu_mallocz(sizeof(CPUS390XState));
+    cpu_exec_init(env);
+    if (!inited) {
+        inited = 1;
+    }
+
+    env->cpu_model_str = cpu_model;
+    cpu_reset(env);
+    qemu_init_vcpu(env);
+    return env;
+}
+
+target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
+{
+    return addr;
+}
+
+void cpu_reset(CPUS390XState *env)
+{
+    if (qemu_loglevel_mask(CPU_LOG_RESET)) {
+        qemu_log("CPU Reset (CPU %d)\n", env->cpu_index);
+        log_cpu_state(env, 0);
+    }
+
+    memset(env, 0, offsetof(CPUS390XState, breakpoints));
+    /* FIXME: reset vector? */
+    tlb_flush(env, 1);
+}

target-s390x/op_helper.c

@@ -0,0 +1,74 @@
+/*
+ *  S/390 helper routines
+ *
+ *  Copyright (c) 2009 Alexander Graf
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
+ */
+
+#include "exec.h"
+
+/*****************************************************************************/
+/* Softmmu support */
+#if !defined (CONFIG_USER_ONLY)
+
+#define MMUSUFFIX _mmu
+
+#define SHIFT 0
+#include "softmmu_template.h"
+
+#define SHIFT 1
+#include "softmmu_template.h"
+
+#define SHIFT 2
+#include "softmmu_template.h"
+
+#define SHIFT 3
+#include "softmmu_template.h"
+
+/* try to fill the TLB and return an exception if error. If retaddr is
+   NULL, it means that the function was called in C code (i.e. not
+   from generated code or from helper.c) */
+/* XXX: fix it to restore all registers */
+void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)
+{
+    TranslationBlock *tb;
+    CPUState *saved_env;
+    unsigned long pc;
+    int ret;
+
+    /* XXX: hack to restore env in all cases, even if not called from
+       generated code */
+    saved_env = env;
+    env = cpu_single_env;
+    ret = cpu_s390x_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
+    if (unlikely(ret != 0)) {
+        if (likely(retaddr)) {
+            /* now we have a real cpu fault */
+            pc = (unsigned long)retaddr;
+            tb = tb_find_pc(pc);
+            if (likely(tb)) {
+                /* the PC is inside the translated code. It means that we have
+                   a virtual CPU fault */
+                cpu_restore_state(tb, env, pc, NULL);
+            }
+        }
+        /* XXX */
+        /* helper_raise_exception_err(env->exception_index, env->error_code); */
+    }
+    env = saved_env;
+}
+
+#endif

target-s390x/translate.c

@@ -0,0 +1,63 @@
+/*
+ *  S/390 translation
+ *
+ *  Copyright (c) 2009 Ulrich Hecht
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
+ */
+
+#include "cpu.h"
+#include "exec-all.h"
+#include "disas.h"
+#include "tcg-op.h"
+#include "qemu-log.h"
+
+void cpu_dump_state(CPUState *env, FILE *f,
+                    int (*cpu_fprintf)(FILE *f, const char *fmt, ...),
+                    int flags)
+{
+    int i;
+    for (i = 0; i < 16; i++) {
+        cpu_fprintf(f, "R%02d=%016lx", i, env->regs[i]);
+        if ((i % 4) == 3) {
+            cpu_fprintf(f, "\n");
+        } else {
+            cpu_fprintf(f, " ");
+        }
+    }
+    for (i = 0; i < 16; i++) {
+        cpu_fprintf(f, "F%02d=%016lx", i, env->fregs[i]);
+        if ((i % 4) == 3) {
+            cpu_fprintf(f, "\n");
+        } else {
+            cpu_fprintf(f, " ");
+        }
+    }
+    cpu_fprintf(f, "PSW=mask %016lx addr %016lx cc %02x\n", env->psw.mask, env->psw.addr, env->cc);
+}
+
+void gen_intermediate_code (CPUState *env, struct TranslationBlock *tb)
+{
+}
+
+void gen_intermediate_code_pc (CPUState *env, struct TranslationBlock *tb)
+{
+}
+
+void gen_pc_load(CPUState *env, TranslationBlock *tb,
+                unsigned long searched_pc, int pc_pos, void *puc)
+{
+    env->psw.addr = gen_opc_pc[pc_pos];
+}