// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2018, Red Hat, Inc.
*
* Tests for Enlightened VMCS, including nested guest state.
*/
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <linux/bitmap.h>
#include "test_util.h"
#include "kvm_util.h"
#include "hyperv.h"
#include "vmx.h"
static int ud_count;
static void guest_ud_handler(struct ex_regs *regs)
{
ud_count++;
regs->rip += 3; /* VMLAUNCH */
}
static void guest_nmi_handler(struct ex_regs *regs)
{
}
static inline void rdmsr_from_l2(uint32_t msr)
{
/* Currently, L1 doesn't preserve GPRs during vmexits. */
__asm__ __volatile__ ("rdmsr" : : "c"(msr) :
"rax", "rbx", "rdx", "rsi", "rdi", "r8", "r9",
"r10", "r11", "r12", "r13", "r14", "r15");
}
/* Exit to L1 from L2 with RDMSR instruction */
void l2_guest_code(void)
{
u64 unused;
GUEST_SYNC(7);
GUEST_SYNC(8);
/* Forced exit to L1 upon restore */
GUEST_SYNC(9);
vmcall();
/* MSR-Bitmap tests */
rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
rdmsr_from_l2(MSR_GS_BASE); /* not intercepted */
vmcall();
rdmsr_from_l2(MSR_GS_BASE); /* intercepted */
/* L2 TLB flush tests */
hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE | HV_HYPERCALL_FAST_BIT, 0x0,
HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES | HV_FLUSH_ALL_PROCESSORS);
rdmsr_from_l2(MSR_FS_BASE);
/*
* Note: hypercall status (RAX) is not preserved correctly by L1 after
* synthetic vmexit, use unchecked version.
*/
__hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE | HV_HYPERCALL_FAST_BIT, 0x0,
HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES | HV_FLUSH_ALL_PROCESSORS,
&unused);
/* Done, exit to L1 and never come back. */
vmcall();
}
void guest_code(struct vmx_pages *vmx_pages, struct hyperv_test_pages *hv_pages,
vm_vaddr_t hv_hcall_page_gpa)
{
#define L2_GUEST_STACK_SIZE 64
unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
wrmsr(HV_X64_MSR_HYPERCALL, hv_hcall_page_gpa);
x2apic_enable();
GUEST_SYNC(1);
GUEST_SYNC(2);
enable_vp_assist(hv_pages->vp_assist_gpa, hv_pages->vp_assist);
evmcs_enable();
GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
GUEST_SYNC(3);
GUEST_ASSERT(load_evmcs(hv_pages));
GUEST_ASSERT(vmptrstz() == hv_pages->enlightened_vmcs_gpa);
GUEST_SYNC(4);
GUEST_ASSERT(vmptrstz() == hv_pages->enlightened_vmcs_gpa);
prepare_vmcs(vmx_pages, l2_guest_code,
&l2_guest_stack[L2_GUEST_STACK_SIZE]);
GUEST_SYNC(5);
GUEST_ASSERT(vmptrstz() == hv_pages->enlightened_vmcs_gpa);
current_evmcs->revision_id = -1u;
GUEST_ASSERT(vmlaunch());
current_evmcs->revision_id = EVMCS_VERSION;
GUEST_SYNC(6);
vmwrite(PIN_BASED_VM_EXEC_CONTROL, vmreadz(PIN_BASED_VM_EXEC_CONTROL) |
PIN_BASED_NMI_EXITING);
/* L2 TLB flush setup */
current_evmcs->partition_assist_page = hv_pages->partition_assist_gpa;
current_evmcs->hv_enlightenments_control.nested_flush_hypercall = 1;
current_evmcs->hv_vm_id = 1;
current_evmcs->hv_vp_id = 1;
current_vp_assist->nested_control.features.directhypercall = 1;
*(u32 *)(hv_pages->partition_assist) = 0;
GUEST_ASSERT(!vmlaunch());
GUEST_ASSERT_EQ(vmreadz(VM_EXIT_REASON), EXIT_REASON_EXCEPTION_NMI);
GUEST_ASSERT_EQ((vmreadz(VM_EXIT_INTR_INFO) & 0xff), NMI_VECTOR);
GUEST_ASSERT(vmptrstz() == hv_pages->enlightened_vmcs_gpa);
/*
* NMI forces L2->L1 exit, resuming L2 and hope that EVMCS is
* up-to-date (RIP points where it should and not at the beginning
* of l2_guest_code(). GUEST_SYNC(9) checkes that.
*/
GUEST_ASSERT(!vmresume());
GUEST_SYNC(10);
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
current_evmcs->guest_rip += 3; /* vmcall */
/* Intercept RDMSR 0xc0000100 */
vmwrite(CPU_BASED_VM_EXEC_CONTROL, vmreadz(CPU_BASED_VM_EXEC_CONTROL) |
CPU_BASED_USE_MSR_BITMAPS);
__set_bit(MSR_FS_BASE & 0x1fff, vmx_pages->msr + 0x400);
GUEST_ASSERT(!vmresume());
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_MSR_READ);
current_evmcs->guest_rip += 2; /* rdmsr */
/* Enable enlightened MSR bitmap */
current_evmcs->hv_enlightenments_control.msr_bitmap = 1;
GUEST_ASSERT(!vmresume());
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_MSR_READ);
current_evmcs->guest_rip += 2; /* rdmsr */
/* Intercept RDMSR 0xc0000101 without telling KVM about it */
__set_bit(MSR_GS_BASE & 0x1fff, vmx_pages->msr + 0x400);
/* Make sure HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP is set */
current_evmcs->hv_clean_fields |= HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP;
GUEST_ASSERT(!vmresume());
/* Make sure we don't see EXIT_REASON_MSR_READ here so eMSR bitmap works */
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
current_evmcs->guest_rip += 3; /* vmcall */
/* Now tell KVM we've changed MSR-Bitmap */
current_evmcs->hv_clean_fields &= ~HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP;
GUEST_ASSERT(!vmresume());
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_MSR_READ);
current_evmcs->guest_rip += 2; /* rdmsr */
/*
* L2 TLB flush test. First VMCALL should be handled directly by L0,
* no VMCALL exit expected.
*/
GUEST_ASSERT(!vmresume());
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_MSR_READ);
current_evmcs->guest_rip += 2; /* rdmsr */
/* Enable synthetic vmexit */
*(u32 *)(hv_pages->partition_assist) = 1;
GUEST_ASSERT(!vmresume());
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == HV_VMX_SYNTHETIC_EXIT_REASON_TRAP_AFTER_FLUSH);
GUEST_ASSERT(!vmresume());
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
GUEST_SYNC(11);
/* Try enlightened vmptrld with an incorrect GPA */
evmcs_vmptrld(0xdeadbeef, hv_pages->enlightened_vmcs);
GUEST_ASSERT(vmlaunch());
GUEST_ASSERT(ud_count == 1);
GUEST_DONE();
}
void inject_nmi(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_events events;
vcpu_events_get(vcpu, &events);
events.nmi.pending = 1;
events.flags |= KVM_VCPUEVENT_VALID_NMI_PENDING;
vcpu_events_set(vcpu, &events);
}
static struct kvm_vcpu *save_restore_vm(struct kvm_vm *vm,
struct kvm_vcpu *vcpu)
{
struct kvm_regs regs1, regs2;
struct kvm_x86_state *state;
state = vcpu_save_state(vcpu);
memset(®s1, 0, sizeof(regs1));
vcpu_regs_get(vcpu, ®s1);
kvm_vm_release(vm);
/* Restore state in a new VM. */
vcpu = vm_recreate_with_one_vcpu(vm);
vcpu_set_hv_cpuid(vcpu);
vcpu_enable_evmcs(vcpu);
vcpu_load_state(vcpu, state);
kvm_x86_state_cleanup(state);
memset(®s2, 0, sizeof(regs2));
vcpu_regs_get(vcpu, ®s2);
TEST_ASSERT(!memcmp(®s1, ®s2, sizeof(regs2)),
"Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
(ulong) regs2.rdi, (ulong) regs2.rsi);
return vcpu;
}
int main(int argc, char *argv[])
{
vm_vaddr_t vmx_pages_gva = 0, hv_pages_gva = 0;
vm_vaddr_t hcall_page;
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
struct ucall uc;
int stage;
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
TEST_REQUIRE(kvm_has_cap(KVM_CAP_NESTED_STATE));
TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS));
TEST_REQUIRE(kvm_hv_cpu_has(HV_X64_NESTED_DIRECT_FLUSH));
vm = vm_create_with_one_vcpu(&vcpu, guest_code);
hcall_page = vm_vaddr_alloc_pages(vm, 1);
memset(addr_gva2hva(vm, hcall_page), 0x0, getpagesize());
vcpu_set_hv_cpuid(vcpu);
vcpu_enable_evmcs(vcpu);
vcpu_alloc_vmx(vm, &vmx_pages_gva);
vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva);
vcpu_args_set(vcpu, 3, vmx_pages_gva, hv_pages_gva, addr_gva2gpa(vm, hcall_page));
vcpu_set_msr(vcpu, HV_X64_MSR_VP_INDEX, vcpu->id);
vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler);
vm_install_exception_handler(vm, NMI_VECTOR, guest_nmi_handler);
pr_info("Running L1 which uses EVMCS to run L2\n");
for (stage = 1;; stage++) {
vcpu_run(vcpu);
TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
switch (get_ucall(vcpu, &uc)) {
case UCALL_ABORT:
REPORT_GUEST_ASSERT(uc);
/* NOT REACHED */
case UCALL_SYNC:
break;
case UCALL_DONE:
goto done;
default:
TEST_FAIL("Unknown ucall %lu", uc.cmd);
}
/* UCALL_SYNC is handled here. */
TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
stage, (ulong)uc.args[1]);
vcpu = save_restore_vm(vm, vcpu);
/* Force immediate L2->L1 exit before resuming */
if (stage == 8) {
pr_info("Injecting NMI into L1 before L2 had a chance to run after restore\n");
inject_nmi(vcpu);
}
/*
* Do KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE for a freshly
* restored VM (before the first KVM_RUN) to check that
* KVM_STATE_NESTED_EVMCS is not lost.
*/
if (stage == 9) {
pr_info("Trying extra KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE cycle\n");
vcpu = save_restore_vm(vm, vcpu);
}
}
done:
kvm_vm_free(vm);
}
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