30493a030f
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[claudio]:
Rebased on commit 68775856 ("target/i386: svm: do not discard high 32 bits")
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210322132800.7470-18-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
110 lines
3.5 KiB
C
110 lines
3.5 KiB
C
/*
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* x86 segmentation related helpers (user-mode code):
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* TSS, interrupts, system calls, jumps and call/task gates, descriptors
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*
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* Copyright (c) 2003 Fabrice Bellard
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "qemu/osdep.h"
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#include "cpu.h"
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#include "exec/helper-proto.h"
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#include "exec/exec-all.h"
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#include "exec/cpu_ldst.h"
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#include "tcg/helper-tcg.h"
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#include "tcg/seg_helper.h"
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#ifdef TARGET_X86_64
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void helper_syscall(CPUX86State *env, int next_eip_addend)
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{
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CPUState *cs = env_cpu(env);
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cs->exception_index = EXCP_SYSCALL;
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env->exception_is_int = 0;
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env->exception_next_eip = env->eip + next_eip_addend;
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cpu_loop_exit(cs);
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}
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#endif /* TARGET_X86_64 */
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/*
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* fake user mode interrupt. is_int is TRUE if coming from the int
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* instruction. next_eip is the env->eip value AFTER the interrupt
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* instruction. It is only relevant if is_int is TRUE or if intno
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* is EXCP_SYSCALL.
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*/
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static void do_interrupt_user(CPUX86State *env, int intno, int is_int,
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int error_code, target_ulong next_eip)
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{
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if (is_int) {
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SegmentCache *dt;
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target_ulong ptr;
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int dpl, cpl, shift;
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uint32_t e2;
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dt = &env->idt;
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if (env->hflags & HF_LMA_MASK) {
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shift = 4;
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} else {
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shift = 3;
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}
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ptr = dt->base + (intno << shift);
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e2 = cpu_ldl_kernel(env, ptr + 4);
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dpl = (e2 >> DESC_DPL_SHIFT) & 3;
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cpl = env->hflags & HF_CPL_MASK;
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/* check privilege if software int */
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if (dpl < cpl) {
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raise_exception_err(env, EXCP0D_GPF, (intno << shift) + 2);
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}
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}
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/* Since we emulate only user space, we cannot do more than
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exiting the emulation with the suitable exception and error
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code. So update EIP for INT 0x80 and EXCP_SYSCALL. */
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if (is_int || intno == EXCP_SYSCALL) {
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env->eip = next_eip;
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}
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}
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void x86_cpu_do_interrupt(CPUState *cs)
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{
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X86CPU *cpu = X86_CPU(cs);
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CPUX86State *env = &cpu->env;
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/* if user mode only, we simulate a fake exception
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which will be handled outside the cpu execution
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loop */
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do_interrupt_user(env, cs->exception_index,
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env->exception_is_int,
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env->error_code,
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env->exception_next_eip);
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/* successfully delivered */
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env->old_exception = -1;
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}
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void cpu_x86_load_seg(CPUX86State *env, X86Seg seg_reg, int selector)
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{
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if (!(env->cr[0] & CR0_PE_MASK) || (env->eflags & VM_MASK)) {
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int dpl = (env->eflags & VM_MASK) ? 3 : 0;
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selector &= 0xffff;
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cpu_x86_load_seg_cache(env, seg_reg, selector,
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(selector << 4), 0xffff,
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DESC_P_MASK | DESC_S_MASK | DESC_W_MASK |
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DESC_A_MASK | (dpl << DESC_DPL_SHIFT));
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} else {
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helper_load_seg(env, seg_reg, selector);
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}
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}
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