aboutsummaryrefslogtreecommitdiff
path: root/target/i386/hvf/x86_task.c
blob: d66dfd766902b5415f156c5242834adf303dc17a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
// This software is licensed under the terms of the GNU General Public
// License version 2, as published by the Free Software Foundation, and
// may be copied, distributed, and modified under those terms.
// 
// 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.
#include "qemu/osdep.h"
#include "panic.h"
#include "qemu-common.h"
#include "qemu/error-report.h"

#include "sysemu/hvf.h"
#include "hvf-i386.h"
#include "vmcs.h"
#include "vmx.h"
#include "x86.h"
#include "x86_descr.h"
#include "x86_mmu.h"
#include "x86_decode.h"
#include "x86_emu.h"
#include "x86_task.h"
#include "x86hvf.h"

#include <Hypervisor/hv.h>
#include <Hypervisor/hv_vmx.h>

#include "hw/i386/apic_internal.h"
#include "qemu/main-loop.h"
#include "qemu/accel.h"
#include "target/i386/cpu.h"

// TODO: taskswitch handling
static void save_state_to_tss32(CPUState *cpu, struct x86_tss_segment32 *tss)
{
    X86CPU *x86_cpu = X86_CPU(cpu);
    CPUX86State *env = &x86_cpu->env;

    /* CR3 and ldt selector are not saved intentionally */
    tss->eip = (uint32_t)env->eip;
    tss->eflags = (uint32_t)env->eflags;
    tss->eax = EAX(env);
    tss->ecx = ECX(env);
    tss->edx = EDX(env);
    tss->ebx = EBX(env);
    tss->esp = ESP(env);
    tss->ebp = EBP(env);
    tss->esi = ESI(env);
    tss->edi = EDI(env);

    tss->es = vmx_read_segment_selector(cpu, R_ES).sel;
    tss->cs = vmx_read_segment_selector(cpu, R_CS).sel;
    tss->ss = vmx_read_segment_selector(cpu, R_SS).sel;
    tss->ds = vmx_read_segment_selector(cpu, R_DS).sel;
    tss->fs = vmx_read_segment_selector(cpu, R_FS).sel;
    tss->gs = vmx_read_segment_selector(cpu, R_GS).sel;
}

static void load_state_from_tss32(CPUState *cpu, struct x86_tss_segment32 *tss)
{
    X86CPU *x86_cpu = X86_CPU(cpu);
    CPUX86State *env = &x86_cpu->env;

    wvmcs(cpu->hvf_fd, VMCS_GUEST_CR3, tss->cr3);

    env->eip = tss->eip;
    env->eflags = tss->eflags | 2;

    /* General purpose registers */
    RAX(env) = tss->eax;
    RCX(env) = tss->ecx;
    RDX(env) = tss->edx;
    RBX(env) = tss->ebx;
    RSP(env) = tss->esp;
    RBP(env) = tss->ebp;
    RSI(env) = tss->esi;
    RDI(env) = tss->edi;

    vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->ldt}}, R_LDTR);
    vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->es}}, R_ES);
    vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->cs}}, R_CS);
    vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->ss}}, R_SS);
    vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->ds}}, R_DS);
    vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->fs}}, R_FS);
    vmx_write_segment_selector(cpu, (x68_segment_selector){{tss->gs}}, R_GS);
}

static int task_switch_32(CPUState *cpu, x68_segment_selector tss_sel, x68_segment_selector old_tss_sel,
                          uint64_t old_tss_base, struct x86_segment_descriptor *new_desc)
{
    struct x86_tss_segment32 tss_seg;
    uint32_t new_tss_base = x86_segment_base(new_desc);
    uint32_t eip_offset = offsetof(struct x86_tss_segment32, eip);
    uint32_t ldt_sel_offset = offsetof(struct x86_tss_segment32, ldt);

    vmx_read_mem(cpu, &tss_seg, old_tss_base, sizeof(tss_seg));
    save_state_to_tss32(cpu, &tss_seg);

    vmx_write_mem(cpu, old_tss_base + eip_offset, &tss_seg.eip, ldt_sel_offset - eip_offset);
    vmx_read_mem(cpu, &tss_seg, new_tss_base, sizeof(tss_seg));

    if (old_tss_sel.sel != 0xffff) {
        tss_seg.prev_tss = old_tss_sel.sel;

        vmx_write_mem(cpu, new_tss_base, &tss_seg.prev_tss, sizeof(tss_seg.prev_tss));
    }
    load_state_from_tss32(cpu, &tss_seg);
    return 0;
}

void vmx_handle_task_switch(CPUState *cpu, x68_segment_selector tss_sel, int reason, bool gate_valid, uint8_t gate, uint64_t gate_type)
{
    uint64_t rip = rreg(cpu->hvf_fd, HV_X86_RIP);
    if (!gate_valid || (gate_type != VMCS_INTR_T_HWEXCEPTION &&
                        gate_type != VMCS_INTR_T_HWINTR &&
                        gate_type != VMCS_INTR_T_NMI)) {
        int ins_len = rvmcs(cpu->hvf_fd, VMCS_EXIT_INSTRUCTION_LENGTH);
        macvm_set_rip(cpu, rip + ins_len);
        return;
    }

    load_regs(cpu);

    struct x86_segment_descriptor curr_tss_desc, next_tss_desc;
    int ret;
    x68_segment_selector old_tss_sel = vmx_read_segment_selector(cpu, R_TR);
    uint64_t old_tss_base = vmx_read_segment_base(cpu, R_TR);
    uint32_t desc_limit;
    struct x86_call_gate task_gate_desc;
    struct vmx_segment vmx_seg;

    X86CPU *x86_cpu = X86_CPU(cpu);
    CPUX86State *env = &x86_cpu->env;

    x86_read_segment_descriptor(cpu, &next_tss_desc, tss_sel);
    x86_read_segment_descriptor(cpu, &curr_tss_desc, old_tss_sel);

    if (reason == TSR_IDT_GATE && gate_valid) {
        int dpl;

        ret = x86_read_call_gate(cpu, &task_gate_desc, gate);

        dpl = task_gate_desc.dpl;
        x68_segment_selector cs = vmx_read_segment_selector(cpu, R_CS);
        if (tss_sel.rpl > dpl || cs.rpl > dpl)
            ;//DPRINTF("emulate_gp");
    }

    desc_limit = x86_segment_limit(&next_tss_desc);
    if (!next_tss_desc.p || ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || desc_limit < 0x2b)) {
        VM_PANIC("emulate_ts");
    }

    if (reason == TSR_IRET || reason == TSR_JMP) {
        curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
        x86_write_segment_descriptor(cpu, &curr_tss_desc, old_tss_sel);
    }

    if (reason == TSR_IRET)
        env->eflags &= ~NT_MASK;

    if (reason != TSR_CALL && reason != TSR_IDT_GATE)
        old_tss_sel.sel = 0xffff;

    if (reason != TSR_IRET) {
        next_tss_desc.type |= (1 << 1); /* set busy flag */
        x86_write_segment_descriptor(cpu, &next_tss_desc, tss_sel);
    }

    if (next_tss_desc.type & 8)
        ret = task_switch_32(cpu, tss_sel, old_tss_sel, old_tss_base, &next_tss_desc);
    else
        //ret = task_switch_16(cpu, tss_sel, old_tss_sel, old_tss_base, &next_tss_desc);
        VM_PANIC("task_switch_16");

    macvm_set_cr0(cpu->hvf_fd, rvmcs(cpu->hvf_fd, VMCS_GUEST_CR0) | CR0_TS);
    x86_segment_descriptor_to_vmx(cpu, tss_sel, &next_tss_desc, &vmx_seg);
    vmx_write_segment_descriptor(cpu, &vmx_seg, R_TR);

    store_regs(cpu);

    hv_vcpu_invalidate_tlb(cpu->hvf_fd);
    hv_vcpu_flush(cpu->hvf_fd);
}