xref: /openbmc/qemu/target/i386/tcg/sysemu/seg_helper.c (revision ffe98631)
1 /*
2  *  x86 segmentation related helpers: (sysemu-only code)
3  *  TSS, interrupts, system calls, jumps and call/task gates, descriptors
4  *
5  *  Copyright (c) 2003 Fabrice Bellard
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "qemu/log.h"
23 #include "cpu.h"
24 #include "exec/helper-proto.h"
25 #include "exec/cpu_ldst.h"
26 #include "tcg/helper-tcg.h"
27 #include "../seg_helper.h"
28 
29 #ifdef TARGET_X86_64
30 void helper_syscall(CPUX86State *env, int next_eip_addend)
31 {
32     int selector;
33 
34     if (!(env->efer & MSR_EFER_SCE)) {
35         raise_exception_err_ra(env, EXCP06_ILLOP, 0, GETPC());
36     }
37     selector = (env->star >> 32) & 0xffff;
38     if (env->hflags & HF_LMA_MASK) {
39         int code64;
40 
41         env->regs[R_ECX] = env->eip + next_eip_addend;
42         env->regs[11] = cpu_compute_eflags(env) & ~RF_MASK;
43 
44         code64 = env->hflags & HF_CS64_MASK;
45 
46         env->eflags &= ~(env->fmask | RF_MASK);
47         cpu_load_eflags(env, env->eflags, 0);
48         cpu_x86_load_seg_cache(env, R_CS, selector & 0xfffc,
49                            0, 0xffffffff,
50                                DESC_G_MASK | DESC_P_MASK |
51                                DESC_S_MASK |
52                                DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK |
53                                DESC_L_MASK);
54         cpu_x86_load_seg_cache(env, R_SS, (selector + 8) & 0xfffc,
55                                0, 0xffffffff,
56                                DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
57                                DESC_S_MASK |
58                                DESC_W_MASK | DESC_A_MASK);
59         if (code64) {
60             env->eip = env->lstar;
61         } else {
62             env->eip = env->cstar;
63         }
64     } else {
65         env->regs[R_ECX] = (uint32_t)(env->eip + next_eip_addend);
66 
67         env->eflags &= ~(IF_MASK | RF_MASK | VM_MASK);
68         cpu_x86_load_seg_cache(env, R_CS, selector & 0xfffc,
69                            0, 0xffffffff,
70                                DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
71                                DESC_S_MASK |
72                                DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK);
73         cpu_x86_load_seg_cache(env, R_SS, (selector + 8) & 0xfffc,
74                                0, 0xffffffff,
75                                DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
76                                DESC_S_MASK |
77                                DESC_W_MASK | DESC_A_MASK);
78         env->eip = (uint32_t)env->star;
79     }
80 }
81 #endif /* TARGET_X86_64 */
82 
83 void handle_even_inj(CPUX86State *env, int intno, int is_int,
84                      int error_code, int is_hw, int rm)
85 {
86     CPUState *cs = env_cpu(env);
87     uint32_t event_inj = x86_ldl_phys(cs, env->vm_vmcb + offsetof(struct vmcb,
88                                                           control.event_inj));
89 
90     if (!(event_inj & SVM_EVTINJ_VALID)) {
91         int type;
92 
93         if (is_int) {
94             type = SVM_EVTINJ_TYPE_SOFT;
95         } else {
96             type = SVM_EVTINJ_TYPE_EXEPT;
97         }
98         event_inj = intno | type | SVM_EVTINJ_VALID;
99         if (!rm && exception_has_error_code(intno)) {
100             event_inj |= SVM_EVTINJ_VALID_ERR;
101             x86_stl_phys(cs, env->vm_vmcb + offsetof(struct vmcb,
102                                              control.event_inj_err),
103                      error_code);
104         }
105         x86_stl_phys(cs,
106                  env->vm_vmcb + offsetof(struct vmcb, control.event_inj),
107                  event_inj);
108     }
109 }
110 
111 void x86_cpu_do_interrupt(CPUState *cs)
112 {
113     X86CPU *cpu = X86_CPU(cs);
114     CPUX86State *env = &cpu->env;
115 
116     if (cs->exception_index == EXCP_VMEXIT) {
117         assert(env->old_exception == -1);
118         do_vmexit(env);
119     } else {
120         do_interrupt_all(cpu, cs->exception_index,
121                          env->exception_is_int,
122                          env->error_code,
123                          env->exception_next_eip, 0);
124         /* successfully delivered */
125         env->old_exception = -1;
126     }
127 }
128 
129 bool x86_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
130 {
131     X86CPU *cpu = X86_CPU(cs);
132     CPUX86State *env = &cpu->env;
133     int intno;
134 
135     interrupt_request = x86_cpu_pending_interrupt(cs, interrupt_request);
136     if (!interrupt_request) {
137         return false;
138     }
139 
140     /* Don't process multiple interrupt requests in a single call.
141      * This is required to make icount-driven execution deterministic.
142      */
143     switch (interrupt_request) {
144     case CPU_INTERRUPT_POLL:
145         cs->interrupt_request &= ~CPU_INTERRUPT_POLL;
146         apic_poll_irq(cpu->apic_state);
147         break;
148     case CPU_INTERRUPT_SIPI:
149         do_cpu_sipi(cpu);
150         break;
151     case CPU_INTERRUPT_SMI:
152         cpu_svm_check_intercept_param(env, SVM_EXIT_SMI, 0, 0);
153         cs->interrupt_request &= ~CPU_INTERRUPT_SMI;
154         do_smm_enter(cpu);
155         break;
156     case CPU_INTERRUPT_NMI:
157         cpu_svm_check_intercept_param(env, SVM_EXIT_NMI, 0, 0);
158         cs->interrupt_request &= ~CPU_INTERRUPT_NMI;
159         env->hflags2 |= HF2_NMI_MASK;
160         do_interrupt_x86_hardirq(env, EXCP02_NMI, 1);
161         break;
162     case CPU_INTERRUPT_MCE:
163         cs->interrupt_request &= ~CPU_INTERRUPT_MCE;
164         do_interrupt_x86_hardirq(env, EXCP12_MCHK, 0);
165         break;
166     case CPU_INTERRUPT_HARD:
167         cpu_svm_check_intercept_param(env, SVM_EXIT_INTR, 0, 0);
168         cs->interrupt_request &= ~(CPU_INTERRUPT_HARD |
169                                    CPU_INTERRUPT_VIRQ);
170         intno = cpu_get_pic_interrupt(env);
171         qemu_log_mask(CPU_LOG_INT,
172                       "Servicing hardware INT=0x%02x\n", intno);
173         do_interrupt_x86_hardirq(env, intno, 1);
174         break;
175     case CPU_INTERRUPT_VIRQ:
176         cpu_svm_check_intercept_param(env, SVM_EXIT_VINTR, 0, 0);
177         intno = x86_ldl_phys(cs, env->vm_vmcb
178                              + offsetof(struct vmcb, control.int_vector));
179         qemu_log_mask(CPU_LOG_INT,
180                       "Servicing virtual hardware INT=0x%02x\n", intno);
181         do_interrupt_x86_hardirq(env, intno, 1);
182         cs->interrupt_request &= ~CPU_INTERRUPT_VIRQ;
183         env->int_ctl &= ~V_IRQ_MASK;
184         break;
185     }
186 
187     /* Ensure that no TB jump will be modified as the program flow was changed.  */
188     return true;
189 }
190 
191 /* check if Port I/O is allowed in TSS */
192 void helper_check_io(CPUX86State *env, uint32_t addr, uint32_t size)
193 {
194     uintptr_t retaddr = GETPC();
195     uint32_t io_offset, val, mask;
196 
197     /* TSS must be a valid 32 bit one */
198     if (!(env->tr.flags & DESC_P_MASK) ||
199         ((env->tr.flags >> DESC_TYPE_SHIFT) & 0xf) != 9 ||
200         env->tr.limit < 103) {
201         goto fail;
202     }
203     io_offset = cpu_lduw_kernel_ra(env, env->tr.base + 0x66, retaddr);
204     io_offset += (addr >> 3);
205     /* Note: the check needs two bytes */
206     if ((io_offset + 1) > env->tr.limit) {
207         goto fail;
208     }
209     val = cpu_lduw_kernel_ra(env, env->tr.base + io_offset, retaddr);
210     val >>= (addr & 7);
211     mask = (1 << size) - 1;
212     /* all bits must be zero to allow the I/O */
213     if ((val & mask) != 0) {
214     fail:
215         raise_exception_err_ra(env, EXCP0D_GPF, 0, retaddr);
216     }
217 }
218