target/i386/hvf/x86_task.c

   1 // This software is licensed under the terms of the GNU General Public
   2 // License version 2, as published by the Free Software Foundation, and
   3 // may be copied, distributed, and modified under those terms.
   4 //
   5 // This program is distributed in the hope that it will be useful,
   6 // but WITHOUT ANY WARRANTY; without even the implied warranty of
   7 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   8 // GNU General Public License for more details.
   9 #include "qemu/osdep.h"
  10 #include "panic.h"
  11 #include "qemu-common.h"
  12 #include "qemu/error-report.h"
  13
  14 #include "sysemu/hvf.h"
  15 #include "hvf-i386.h"
  16 #include "vmcs.h"
  17 #include "vmx.h"
  18 #include "x86.h"
  19 #include "x86_descr.h"
  20 #include "x86_mmu.h"
  21 #include "x86_decode.h"
  22 #include "x86_emu.h"
  23 #include "x86_task.h"
  24 #include "x86hvf.h"
  25
  26 #include <Hypervisor/hv.h>
  27 #include <Hypervisor/hv_vmx.h>
  28
  29 #include "hw/i386/apic_internal.h"
  30 #include "qemu/main-loop.h"
  31 #include "qemu/accel.h"
  32 #include "target/i386/cpu.h"
  33
  34 // TODO: taskswitch handling
  35 static void save_state_to_tss32(CPUState *cpu, struct x86_tss_segment32 *tss)
  36 {
  37     X86CPU *x86_cpu = X86_CPU(cpu);
  38     CPUX86State *env = &x86_cpu->env;
  39
  40     /* CR3 and ldt selector are not saved intentionally */
  41     tss->eip = (uint32_t)env->eip;
  42     tss->eflags = (uint32_t)env->eflags;
  43     tss->eax = EAX(env);
  44     tss->ecx = ECX(env);
  45     tss->edx = EDX(env);
  46     tss->ebx = EBX(env);
  47     tss->esp = ESP(env);
  48     tss->ebp = EBP(env);
  49     tss->esi = ESI(env);
  50     tss->edi = EDI(env);
  51
  52     tss->es = vmx_read_segment_selector(cpu, R_ES).sel;
  53     tss->cs = vmx_read_segment_selector(cpu, R_CS).sel;
  54     tss->ss = vmx_read_segment_selector(cpu, R_SS).sel;
  55     tss->ds = vmx_read_segment_selector(cpu, R_DS).sel;
  56     tss->fs = vmx_read_segment_selector(cpu, R_FS).sel;
  57     tss->gs = vmx_read_segment_selector(cpu, R_GS).sel;
  58 }
  59
  60 static void load_state_from_tss32(CPUState *cpu, struct x86_tss_segment32 *tss)
  61 {
  62     X86CPU *x86_cpu = X86_CPU(cpu);
  63     CPUX86State *env = &x86_cpu->env;
  64
  65     wvmcs(cpu->hvf_fd, VMCS_GUEST_CR3, tss->cr3);
  66
  67     env->eip = tss->eip;
  68     env->eflags = tss->eflags | 2;
  69
  70     /* General purpose registers */
  71     RAX(env) = tss->eax;
  72     RCX(env) = tss->ecx;
  73     RDX(env) = tss->edx;
  74     RBX(env) = tss->ebx;
  75     RSP(env) = tss->esp;
  76     RBP(env) = tss->ebp;
  77     RSI(env) = tss->esi;
  78     RDI(env) = tss->edi;
  79
  80     vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->ldt}}, R_LDTR);
  81     vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->es}}, R_ES);
  82     vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->cs}}, R_CS);
  83     vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->ss}}, R_SS);
  84     vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->ds}}, R_DS);
  85     vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->fs}}, R_FS);
  86     vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->gs}}, R_GS);
  87 }
  88
  89 static int task_switch_32(CPUState *cpu, x68_segment_selector tss_sel, x68_segment_selector old_tss_sel,
  90                           uint64_t old_tss_base, struct x86_segment_descriptor *new_desc)
  91 {
  92     struct x86_tss_segment32 tss_seg;
  93     uint32_t new_tss_base = x86_segment_base(new_desc);
  94     uint32_t eip_offset = offsetof(struct x86_tss_segment32, eip);
  95     uint32_t ldt_sel_offset = offsetof(struct x86_tss_segment32, ldt);
  96
  97     vmx_read_mem(cpu, &tss_seg, old_tss_base, sizeof(tss_seg));
  98     save_state_to_tss32(cpu, &tss_seg);
  99
 100     vmx_write_mem(cpu, old_tss_base + eip_offset, &tss_seg.eip, ldt_sel_offset - eip_offset);
 101     vmx_read_mem(cpu, &tss_seg, new_tss_base, sizeof(tss_seg));
 102
 103     if (old_tss_sel.sel != 0xffff) {
 104         tss_seg.prev_tss = old_tss_sel.sel;
 105
 106         vmx_write_mem(cpu, new_tss_base, &tss_seg.prev_tss, sizeof(tss_seg.prev_tss));
 107     }
 108     load_state_from_tss32(cpu, &tss_seg);
 109     return 0;
 110 }
 111
 112 void vmx_handle_task_switch(CPUState *cpu, x68_segment_selector tss_sel, int reason, bool gate_valid, uint8_t gate, uint64_t gate_type)
 113 {
 114     uint64_t rip = rreg(cpu->hvf_fd, HV_X86_RIP);
 115     if (!gate_valid || (gate_type != VMCS_INTR_T_HWEXCEPTION &&
 116                         gate_type != VMCS_INTR_T_HWINTR &&
 117                         gate_type != VMCS_INTR_T_NMI)) {
 118         int ins_len = rvmcs(cpu->hvf_fd, VMCS_EXIT_INSTRUCTION_LENGTH);
 119         macvm_set_rip(cpu, rip + ins_len);
 120         return;
 121     }
 122
 123     load_regs(cpu);
 124
 125     struct x86_segment_descriptor curr_tss_desc, next_tss_desc;
 126     int ret;
 127     x68_segment_selector old_tss_sel = vmx_read_segment_selector(cpu, R_TR);
 128     uint64_t old_tss_base = vmx_read_segment_base(cpu, R_TR);
 129     uint32_t desc_limit;
 130     struct x86_call_gate task_gate_desc;
 131     struct vmx_segment vmx_seg;
 132
 133     X86CPU *x86_cpu = X86_CPU(cpu);
 134     CPUX86State *env = &x86_cpu->env;
 135
 136     x86_read_segment_descriptor(cpu, &next_tss_desc, tss_sel);
 137     x86_read_segment_descriptor(cpu, &curr_tss_desc, old_tss_sel);
 138
 139     if (reason == TSR_IDT_GATE && gate_valid) {
 140         int dpl;
 141
 142         ret = x86_read_call_gate(cpu, &task_gate_desc, gate);
 143
 144         dpl = task_gate_desc.dpl;
 145         x68_segment_selector cs = vmx_read_segment_selector(cpu, R_CS);
 146         if (tss_sel.rpl > dpl || cs.rpl > dpl)
 147             ;//DPRINTF("emulate_gp");
 148     }
 149
 150     desc_limit = x86_segment_limit(&next_tss_desc);
 151     if (!next_tss_desc.p || ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || desc_limit < 0x2b)) {
 152         VM_PANIC("emulate_ts");
 153     }
 154
 155     if (reason == TSR_IRET || reason == TSR_JMP) {
 156         curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
 157         x86_write_segment_descriptor(cpu, &curr_tss_desc, old_tss_sel);
 158     }
 159
 160     if (reason == TSR_IRET)
 161         env->eflags &= ~NT_MASK;
 162
 163     if (reason != TSR_CALL && reason != TSR_IDT_GATE)
 164         old_tss_sel.sel = 0xffff;
 165
 166     if (reason != TSR_IRET) {
 167         next_tss_desc.type |= (1 << 1); /* set busy flag */
 168         x86_write_segment_descriptor(cpu, &next_tss_desc, tss_sel);
 169     }
 170
 171     if (next_tss_desc.type & 8)
 172         ret = task_switch_32(cpu, tss_sel, old_tss_sel, old_tss_base, &next_tss_desc);
 173     else
 174         //ret = task_switch_16(cpu, tss_sel, old_tss_sel, old_tss_base, &next_tss_desc);
 175         VM_PANIC("task_switch_16");
 176
 177     macvm_set_cr0(cpu->hvf_fd, rvmcs(cpu->hvf_fd, VMCS_GUEST_CR0) | CR0_TS);
 178     x86_segment_descriptor_to_vmx(cpu, tss_sel, &next_tss_desc, &vmx_seg);
 179     vmx_write_segment_descriptor(cpu, &vmx_seg, R_TR);
 180
 181     store_regs(cpu);
 182
 183     hv_vcpu_invalidate_tlb(cpu->hvf_fd);
 184     hv_vcpu_flush(cpu->hvf_fd);
 185 }