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qemu/bsd-user/i386/target_arch_cpu.h
Paolo Bonzini 63fd8ef080 target/i386: implement SYSCALL/SYSRET in 32-bit emulators 
AMD supports both 32-bit and 64-bit SYSCALL/SYSRET, but the TCG only
exposes it for 64-bit targets.  For system emulation just reuse the
helper; for user-mode emulation the ABI is the same as "int $80".

The BSDs does not support any fast system call mechanism in 32-bit
mode so add to bsd-user the same stub that FreeBSD has for 64-bit
compatibility mode.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-06-26 10:23:56 +02:00

203 lines
6.5 KiB
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/*
* i386 cpu init and loop
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef TARGET_ARCH_CPU_H
#define TARGET_ARCH_CPU_H
#include "target_arch.h"
#include "signal-common.h"
#define TARGET_DEFAULT_CPU_MODEL "qemu32"
static inline void target_cpu_init(CPUX86State *env,
struct target_pt_regs *regs)
{
uint64_t *gdt_table;
env->cr[0] = CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK;
env->hflags |= HF_PE_MASK | HF_CPL_MASK;
if (env->features[FEAT_1_EDX] & CPUID_SSE) {
env->cr[4] |= CR4_OSFXSR_MASK;
env->hflags |= HF_OSFXSR_MASK;
}
/* flags setup : we activate the IRQs by default as in user mode */
env->eflags |= IF_MASK;
/* register setup */
env->regs[R_EAX] = regs->eax;
env->regs[R_EBX] = regs->ebx;
env->regs[R_ECX] = regs->ecx;
env->regs[R_EDX] = regs->edx;
env->regs[R_ESI] = regs->esi;
env->regs[R_EDI] = regs->edi;
env->regs[R_EBP] = regs->ebp;
env->regs[R_ESP] = regs->esp;
env->eip = regs->eip;
/* interrupt setup */
env->idt.limit = 255;
env->idt.base = target_mmap(0, sizeof(uint64_t) * (env->idt.limit + 1),
PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
bsd_i386_set_idt_base(env->idt.base);
bsd_i386_set_idt(0, 0);
bsd_i386_set_idt(1, 0);
bsd_i386_set_idt(2, 0);
bsd_i386_set_idt(3, 3);
bsd_i386_set_idt(4, 3);
bsd_i386_set_idt(5, 0);
bsd_i386_set_idt(6, 0);
bsd_i386_set_idt(7, 0);
bsd_i386_set_idt(8, 0);
bsd_i386_set_idt(9, 0);
bsd_i386_set_idt(10, 0);
bsd_i386_set_idt(11, 0);
bsd_i386_set_idt(12, 0);
bsd_i386_set_idt(13, 0);
bsd_i386_set_idt(14, 0);
bsd_i386_set_idt(15, 0);
bsd_i386_set_idt(16, 0);
bsd_i386_set_idt(17, 0);
bsd_i386_set_idt(18, 0);
bsd_i386_set_idt(19, 0);
bsd_i386_set_idt(0x80, 3);
/* segment setup */
env->gdt.base = target_mmap(0, sizeof(uint64_t) * TARGET_GDT_ENTRIES,
PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
env->gdt.limit = sizeof(uint64_t) * TARGET_GDT_ENTRIES - 1;
gdt_table = g2h_untagged(env->gdt.base);
bsd_i386_write_dt(&gdt_table[__USER_CS >> 3], 0, 0xfffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
(3 << DESC_DPL_SHIFT) | (0xa << DESC_TYPE_SHIFT));
bsd_i386_write_dt(&gdt_table[__USER_DS >> 3], 0, 0xfffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
(3 << DESC_DPL_SHIFT) | (0x2 << DESC_TYPE_SHIFT));
cpu_x86_load_seg(env, R_CS, __USER_CS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_FS, __USER_DS);
cpu_x86_load_seg(env, R_GS, __USER_DS);
/* This hack makes Wine work... */
env->segs[R_FS].selector = 0;
}
static inline void target_cpu_loop(CPUX86State *env)
{
CPUState *cs = env_cpu(env);
int trapnr;
abi_ulong pc;
/* target_siginfo_t info; */
for (;;) {
cpu_exec_start(cs);
trapnr = cpu_exec(cs);
cpu_exec_end(cs);
process_queued_cpu_work(cs);
switch (trapnr) {
case 0x80: {
/* syscall from int $0x80 */
abi_ulong params = (abi_ulong) env->regs[R_ESP] +
sizeof(int32_t);
int32_t syscall_nr = env->regs[R_EAX];
int32_t arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8;
if (syscall_nr == TARGET_FREEBSD_NR_syscall) {
get_user_s32(syscall_nr, params);
params += sizeof(int32_t);
} else if (syscall_nr == TARGET_FREEBSD_NR___syscall) {
get_user_s32(syscall_nr, params);
params += sizeof(int64_t);
}
get_user_s32(arg1, params);
params += sizeof(int32_t);
get_user_s32(arg2, params);
params += sizeof(int32_t);
get_user_s32(arg3, params);
params += sizeof(int32_t);
get_user_s32(arg4, params);
params += sizeof(int32_t);
get_user_s32(arg5, params);
params += sizeof(int32_t);
get_user_s32(arg6, params);
params += sizeof(int32_t);
get_user_s32(arg7, params);
params += sizeof(int32_t);
get_user_s32(arg8, params);
env->regs[R_EAX] = do_freebsd_syscall(env,
syscall_nr,
arg1,
arg2,
arg3,
arg4,
arg5,
arg6,
arg7,
arg8);
}
if (((abi_ulong)env->regs[R_EAX]) >= (abi_ulong)(-515)) {
env->regs[R_EAX] = -env->regs[R_EAX];
env->eflags |= CC_C;
} else {
env->eflags &= ~CC_C;
}
break;
case EXCP_SYSCALL:
/* doesn't do anything */
break;
case EXCP_INTERRUPT:
/* just indicate that signals should be handled asap */
break;
case EXCP_ATOMIC:
cpu_exec_step_atomic(cs);
break;
default:
pc = env->segs[R_CS].base + env->eip;
fprintf(stderr, "qemu: 0x%08lx: unhandled CPU exception 0x%x - "
"aborting\n", (long)pc, trapnr);
abort();
}
process_pending_signals(env);
}
}
static inline void target_cpu_clone_regs(CPUX86State *env, target_ulong newsp)
{
if (newsp) {
env->regs[R_ESP] = newsp;
}
env->regs[R_EAX] = 0;
}
static inline void target_cpu_reset(CPUArchState *env)
{
cpu_reset(env_cpu(env));
}
#endif /* TARGET_ARCH_CPU_H */
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