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Pentium II: Add SYSENTER-related MSRs, update SYSENTER validiation as documented by Intel

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Jonathan Campbell
2021-11-22 07:47:51 -08:00
parent 853611aef7
commit 132cc18e36
1 changed files with 37 additions and 1 deletions
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38
src/cpu/cpu.cpp
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@@ -87,6 +87,11 @@ extern bool auto_determine_dynamic_core_paging;
bool cpu_double_fault_enable;
bool cpu_triple_fault_reset;
/* SYSENTER/SYSEXIT */
uint16_t cpu_sep_cs = 0; /* MSR 0x174h value of CS */
uint32_t cpu_sep_esp = 0; /* MSR 0x175h value of ESP */
uint32_t cpu_sep_eip = 0; /* MSR 0x176h value of EIP */
int cpu_rep_max = 0;
Bitu DEBUG_EnableDebugger(void);
@@ -4128,12 +4133,14 @@ void CPU_ForceV86FakeIO_Out(Bitu port,Bitu val,Bitu len) {
/* pentium II fast system call */
bool CPU_SYSENTER() {
if (!enable_syscall) return false;
UNBLOCKED_LOG(LOG_CPU,LOG_NORMAL)("SYSENTER: UNIMPLEMENTED");
if (!cpu.pmode || cpu_sep_cs == 0) return false; /* CS != 0 and not real mode */
UNBLOCKED_LOG(LOG_CPU,LOG_NORMAL)("SYSENTER: UNIMPLEMENTED CS=%04x EIP=%08x ESP=%08x",cpu_sep_cs,cpu_sep_eip,cpu_sep_esp);
return false; /* TODO */
}
bool CPU_SYSEXIT() {
if (!enable_syscall) return false;
if (!cpu.pmode || cpu_sep_cs == 0) return false; /* CS != 0 and not real mode */
UNBLOCKED_LOG(LOG_CPU,LOG_NORMAL)("SYSEXIT: UNIMPLEMENTED");
return false; /* TODO */
}
@@ -4146,10 +4153,26 @@ bool CPU_RDMSR() {
case 0x0000001b: /* Local APIC */
/* NTS: Windows ME assumes this MSR is present if we report ourself as a Pentium II,
* instead of, you know, using CPUID */
/* NTS: Apparently the Linux kernel also assumes this register is present. */
if (CPU_ArchitectureType<CPU_ARCHTYPE_PENTIUMII) return false;
reg_edx = reg_eax = 0;
UNBLOCKED_LOG(LOG_CPU,LOG_NORMAL)("RDMSR: Faking Local APIC");
return true;
case 0x00000174: /* SYSENTER CS selector */
if (CPU_ArchitectureType<CPU_ARCHTYPE_PENTIUMII || !enable_syscall) return false;
reg_edx = 0;
reg_eax = cpu_sep_cs;
break;
case 0x00000175: /* SYSENTER ESP stack pointer */
if (CPU_ArchitectureType<CPU_ARCHTYPE_PENTIUMII || !enable_syscall) return false;
reg_edx = 0;
reg_eax = cpu_sep_esp;
break;
case 0x00000176: /* SYSENTER EIP instruction pointer */
if (CPU_ArchitectureType<CPU_ARCHTYPE_PENTIUMII || !enable_syscall) return false;
reg_edx = 0;
reg_eax = cpu_sep_eip;
break;
default:
UNBLOCKED_LOG(LOG_CPU,LOG_NORMAL)("RDMSR: Unknown register 0x%08lx",(unsigned long)reg_ecx);
break;
@@ -4173,10 +4196,23 @@ bool CPU_WRMSR() {
* instead of, you know, using CPUID. It will also set the enable bit, even if
* this register was 0x00000000 when it booted. Fortunately, Windows ME still
* runs properly if we silently ignore the write and leave it 0x00000000. */
/* NTS: Apparently the Linux kernel also assumes this register is present. */
if (CPU_ArchitectureType<CPU_ARCHTYPE_PENTIUMII) return false;
UNBLOCKED_LOG(LOG_CPU,LOG_NORMAL)("WRMSR: Faking Local APIC");
if (reg_eax & 0x800) UNBLOCKED_LOG(LOG_CPU,LOG_WARN)("Guest OS is attempting to enable the Local APIC which we do not emulate yet");
return true;
case 0x00000174: /* SYSENTER CS selector */
if (CPU_ArchitectureType<CPU_ARCHTYPE_PENTIUMII || !enable_syscall) return false;
cpu_sep_cs = (uint16_t)(reg_eax & 0xFFFFu);
break;
case 0x00000175: /* SYSENTER ESP stack pointer */
if (CPU_ArchitectureType<CPU_ARCHTYPE_PENTIUMII || !enable_syscall) return false;
cpu_sep_esp = reg_esp;
break;
case 0x00000176: /* SYSENTER EIP instruction pointer */
if (CPU_ArchitectureType<CPU_ARCHTYPE_PENTIUMII || !enable_syscall) return false;
cpu_sep_eip = reg_eip;
break;
default:
UNBLOCKED_LOG(LOG_CPU,LOG_NORMAL)("WRMSR: Unknown register 0x%08lx (write 0x%08lx:0x%08lx)",(unsigned long)reg_ecx,(unsigned long)reg_edx,(unsigned long)reg_eax);
break;