/*
* tools/testing/selftests/kvm/lib/x86.c
*
* Copyright (C) 2018, Google LLC.
*
* This work is licensed under the terms of the GNU GPL, version 2.
*/
#define _GNU_SOURCE /* for program_invocation_name */
#include "test_util.h"
#include "kvm_util.h"
#include "x86.h"
#include "vmx.h"
/* Create a default VM for VMX tests.
*
* Input Args:
* vcpuid - The id of the single VCPU to add to the VM.
* guest_code - The vCPU's entry point
*
* Output Args: None
*
* Return:
* Pointer to opaque structure that describes the created VM.
*/
struct kvm_vm *
vm_create_default_vmx(uint32_t vcpuid, vmx_guest_code_t guest_code)
{
struct kvm_cpuid2 *cpuid;
struct kvm_vm *vm;
vm_vaddr_t vmxon_vaddr;
vm_paddr_t vmxon_paddr;
vm_vaddr_t vmcs_vaddr;
vm_paddr_t vmcs_paddr;
vm = vm_create_default(vcpuid, (void *) guest_code);
/* Enable nesting in CPUID */
vcpu_set_cpuid(vm, vcpuid, kvm_get_supported_cpuid());
/* Setup of a region of guest memory for the vmxon region. */
vmxon_vaddr = vm_vaddr_alloc(vm, getpagesize(), 0, 0, 0);
vmxon_paddr = addr_gva2gpa(vm, vmxon_vaddr);
/* Setup of a region of guest memory for a vmcs. */
vmcs_vaddr = vm_vaddr_alloc(vm, getpagesize(), 0, 0, 0);
vmcs_paddr = addr_gva2gpa(vm, vmcs_vaddr);
vcpu_args_set(vm, vcpuid, 4, vmxon_vaddr, vmxon_paddr, vmcs_vaddr,
vmcs_paddr);
return vm;
}
void prepare_for_vmx_operation(void)
{
uint64_t feature_control;
uint64_t required;
unsigned long cr0;
unsigned long cr4;
/*
* Ensure bits in CR0 and CR4 are valid in VMX operation:
* - Bit X is 1 in _FIXED0: bit X is fixed to 1 in CRx.
* - Bit X is 0 in _FIXED1: bit X is fixed to 0 in CRx.
*/
__asm__ __volatile__("mov %%cr0, %0" : "=r"(cr0) : : "memory");
cr0 &= rdmsr(MSR_IA32_VMX_CR0_FIXED1);
cr0 |= rdmsr(MSR_IA32_VMX_CR0_FIXED0);
__asm__ __volatile__("mov %0, %%cr0" : : "r"(cr0) : "memory");
__asm__ __volatile__("mov %%cr4, %0" : "=r"(cr4) : : "memory");
cr4 &= rdmsr(MSR_IA32_VMX_CR4_FIXED1);
cr4 |= rdmsr(MSR_IA32_VMX_CR4_FIXED0);
/* Enable VMX operation */
cr4 |= X86_CR4_VMXE;
__asm__ __volatile__("mov %0, %%cr4" : : "r"(cr4) : "memory");
/*
* Configure IA32_FEATURE_CONTROL MSR to allow VMXON:
* Bit 0: Lock bit. If clear, VMXON causes a #GP.
* Bit 2: Enables VMXON outside of SMX operation. If clear, VMXON
* outside of SMX causes a #GP.
*/
required = FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
required |= FEATURE_CONTROL_LOCKED;
feature_control = rdmsr(MSR_IA32_FEATURE_CONTROL);
if ((feature_control & required) != required)
wrmsr(MSR_IA32_FEATURE_CONTROL, feature_control | required);
}
/*
* Initialize the control fields to the most basic settings possible.
*/
static inline void init_vmcs_control_fields(void)
{
vmwrite(VIRTUAL_PROCESSOR_ID, 0);
vmwrite(POSTED_INTR_NV, 0);
vmwrite(PIN_BASED_VM_EXEC_CONTROL, rdmsr(MSR_IA32_VMX_PINBASED_CTLS));
vmwrite(CPU_BASED_VM_EXEC_CONTROL, rdmsr(MSR_IA32_VMX_PROCBASED_CTLS));
vmwrite(EXCEPTION_BITMAP, 0);
vmwrite(PAGE_FAULT_ERROR_CODE_MASK, 0);
vmwrite(PAGE_FAULT_ERROR_CODE_MATCH, -1); /* Never match */
vmwrite(CR3_TARGET_COUNT, 0);
vmwrite(VM_EXIT_CONTROLS, rdmsr(MSR_IA32_VMX_EXIT_CTLS) |
VM_EXIT_HOST_ADDR_SPACE_SIZE); /* 64-bit host */
vmwrite(VM_EXIT_MSR_STORE_COUNT, 0);
vmwrite(VM_EXIT_MSR_LOAD_COUNT, 0);
vmwrite(VM_ENTRY_CONTROLS, rdmsr(MSR_IA32_VMX_ENTRY_CTLS) |
VM_ENTRY_IA32E_MODE); /* 64-bit guest */
vmwrite(VM_ENTRY_MSR_LOAD_COUNT, 0);
vmwrite(VM_ENTRY_INTR_INFO_FIELD, 0);
vmwrite(TPR_THRESHOLD, 0);
vmwrite(SECONDARY_VM_EXEC_CONTROL, 0);
vmwrite(CR0_GUEST_HOST_MASK, 0);
vmwrite(CR4_GUEST_HOST_MASK, 0);
vmwrite(CR0_READ_SHADOW, get_cr0());
vmwrite(CR4_READ_SHADOW, get_cr4());
}
/*
* Initialize the host state fields based on the current host state, with
* the exception of HOST_RSP and HOST_RIP, which should be set by vmlaunch
* or vmresume.
*/
static inline void init_vmcs_host_state(void)
{
uint32_t exit_controls = vmreadz(VM_EXIT_CONTROLS);
vmwrite(HOST_ES_SELECTOR, get_es());
vmwrite(HOST_CS_SELECTOR, get_cs());
vmwrite(HOST_SS_SELECTOR, get_ss());
vmwrite(HOST_DS_SELECTOR, get_ds());
vmwrite(HOST_FS_SELECTOR, get_fs());
vmwrite(HOST_GS_SELECTOR, get_gs());
vmwrite(HOST_TR_SELECTOR, get_tr());
if (exit_controls & VM_EXIT_LOAD_IA32_PAT)
vmwrite(HOST_IA32_PAT, rdmsr(MSR_IA32_CR_PAT));
if (exit_controls & VM_EXIT_LOAD_IA32_EFER)
vmwrite(HOST_IA32_EFER, rdmsr(MSR_EFER));
if (exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
vmwrite(HOST_IA32_PERF_GLOBAL_CTRL,
rdmsr(MSR_CORE_PERF_GLOBAL_CTRL));
vmwrite(HOST_IA32_SYSENTER_CS, rdmsr(MSR_IA32_SYSENTER_CS));
vmwrite(HOST_CR0, get_cr0());
vmwrite(HOST_CR3, get_cr3());
vmwrite(HOST_CR4, get_cr4());
vmwrite(HOST_FS_BASE, rdmsr(MSR_FS_BASE));
vmwrite(HOST_GS_BASE, rdmsr(MSR_GS_BASE));
vmwrite(HOST_TR_BASE,
get_desc64_base((struct desc64 *)(get_gdt_base() + get_tr())));
vmwrite(HOST_GDTR_BASE, get_gdt_base());
vmwrite(HOST_IDTR_BASE, get_idt_base());
vmwrite(HOST_IA32_SYSENTER_ESP, rdmsr(MSR_IA32_SYSENTER_ESP));
vmwrite(HOST_IA32_SYSENTER_EIP, rdmsr(MSR_IA32_SYSENTER_EIP));
}
/*
* Initialize the guest state fields essentially as a clone of
* the host state fields. Some host state fields have fixed
* values, and we set the corresponding guest state fields accordingly.
*/
static inline void init_vmcs_guest_state(void *rip, void *rsp)
{
vmwrite(GUEST_ES_SELECTOR, vmreadz(HOST_ES_SELECTOR));
vmwrite(GUEST_CS_SELECTOR, vmreadz(HOST_CS_SELECTOR));
vmwrite(GUEST_SS_SELECTOR, vmreadz(HOST_SS_SELECTOR));
vmwrite(GUEST_DS_SELECTOR, vmreadz(HOST_DS_SELECTOR));
vmwrite(GUEST_FS_SELECTOR, vmreadz(HOST_FS_SELECTOR));
vmwrite(GUEST_GS_SELECTOR, vmreadz(HOST_GS_SELECTOR));
vmwrite(GUEST_LDTR_SELECTOR, 0);
vmwrite(GUEST_TR_SELECTOR, vmreadz(HOST_TR_SELECTOR));
vmwrite(GUEST_INTR_STATUS, 0);
vmwrite(GUEST_PML_INDEX, 0);
vmwrite(VMCS_LINK_POINTER, -1ll);
vmwrite(GUEST_IA32_DEBUGCTL, 0);
vmwrite(GUEST_IA32_PAT, vmreadz(HOST_IA32_PAT));
vmwrite(GUEST_IA32_EFER, vmreadz(HOST_IA32_EFER));
vmwrite(GUEST_IA32_PERF_GLOBAL_CTRL,
vmreadz(HOST_IA32_PERF_GLOBAL_CTRL));
vmwrite(GUEST_ES_LIMIT, -1);
vmwrite(GUEST_CS_LIMIT, -1);
vmwrite(GUEST_SS_LIMIT, -1);
vmwrite(GUEST_DS_LIMIT, -1);
vmwrite(GUEST_FS_LIMIT, -1);
vmwrite(GUEST_GS_LIMIT, -1);
vmwrite(GUEST_LDTR_LIMIT, -1);
vmwrite(GUEST_TR_LIMIT, 0x67);
vmwrite(GUEST_GDTR_LIMIT, 0xffff);
vmwrite(GUEST_IDTR_LIMIT, 0xffff);
vmwrite(GUEST_ES_AR_BYTES,
vmreadz(GUEST_ES_SELECTOR) == 0 ? 0x10000 : 0xc093);
vmwrite(GUEST_CS_AR_BYTES, 0xa09b);
vmwrite(GUEST_SS_AR_BYTES, 0xc093);
vmwrite(GUEST_DS_AR_BYTES,
vmreadz(GUEST_DS_SELECTOR) == 0 ? 0x10000 : 0xc093);
vmwrite(GUEST_FS_AR_BYTES,
vmreadz(GUEST_FS_SELECTOR) == 0 ? 0x10000 : 0xc093);
vmwrite(GUEST_GS_AR_BYTES,
vmreadz(GUEST_GS_SELECTOR) == 0 ? 0x10000 : 0xc093);
vmwrite(GUEST_LDTR_AR_BYTES, 0x10000);
vmwrite(GUEST_TR_AR_BYTES, 0x8b);
vmwrite(GUEST_INTERRUPTIBILITY_INFO, 0);
vmwrite(GUEST_ACTIVITY_STATE, 0);
vmwrite(GUEST_SYSENTER_CS, vmreadz(HOST_IA32_SYSENTER_CS));
vmwrite(VMX_PREEMPTION_TIMER_VALUE, 0);
vmwrite(GUEST_CR0, vmreadz(HOST_CR0));
vmwrite(GUEST_CR3, vmreadz(HOST_CR3));
vmwrite(GUEST_CR4, vmreadz(HOST_CR4));
vmwrite(GUEST_ES_BASE, 0);
vmwrite(GUEST_CS_BASE, 0);
vmwrite(GUEST_SS_BASE, 0);
vmwrite(GUEST_DS_BASE, 0);
vmwrite(GUEST_FS_BASE, vmreadz(HOST_FS_BASE));
vmwrite(GUEST_GS_BASE, vmreadz(HOST_GS_BASE));
vmwrite(GUEST_LDTR_BASE, 0);
vmwrite(GUEST_TR_BASE, vmreadz(HOST_TR_BASE));
vmwrite(GUEST_GDTR_BASE, vmreadz(HOST_GDTR_BASE));
vmwrite(GUEST_IDTR_BASE, vmreadz(HOST_IDTR_BASE));
vmwrite(GUEST_DR7, 0x400);
vmwrite(GUEST_RSP, (uint64_t)rsp);
vmwrite(GUEST_RIP, (uint64_t)rip);
vmwrite(GUEST_RFLAGS, 2);
vmwrite(GUEST_PENDING_DBG_EXCEPTIONS, 0);
vmwrite(GUEST_SYSENTER_ESP, vmreadz(HOST_IA32_SYSENTER_ESP));
vmwrite(GUEST_SYSENTER_EIP, vmreadz(HOST_IA32_SYSENTER_EIP));
}
void prepare_vmcs(void *guest_rip, void *guest_rsp)
{
init_vmcs_control_fields();
init_vmcs_host_state();
init_vmcs_guest_state(guest_rip, guest_rsp);
}
