--- /dev/null
+/*
+ * vmx_set_nested_state_test
+ *
+ * Copyright (C) 2019, Google LLC.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ * This test verifies the integrity of calling the ioctl KVM_SET_NESTED_STATE.
+ */
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+#include "vmx.h"
+
+#include <errno.h>
+#include <linux/kvm.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+/*
+ * Mirror of VMCS12_REVISION in arch/x86/kvm/vmx/vmcs12.h. If that value
+ * changes this should be updated.
+ */
+#define VMCS12_REVISION 0x11e57ed0
+#define VCPU_ID 5
+
+void test_nested_state(struct kvm_vm *vm, struct kvm_nested_state *state)
+{
+ volatile struct kvm_run *run;
+
+ vcpu_nested_state_set(vm, VCPU_ID, state, false);
+ run = vcpu_state(vm, VCPU_ID);
+ vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
+ "Got exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s),\n",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+}
+
+void test_nested_state_expect_errno(struct kvm_vm *vm,
+ struct kvm_nested_state *state,
+ int expected_errno)
+{
+ volatile struct kvm_run *run;
+ int rv;
+
+ rv = vcpu_nested_state_set(vm, VCPU_ID, state, true);
+ TEST_ASSERT(rv == -1 && errno == expected_errno,
+ "Expected %s (%d) from vcpu_nested_state_set but got rv: %i errno: %s (%d)",
+ strerror(expected_errno), expected_errno, rv, strerror(errno),
+ errno);
+ run = vcpu_state(vm, VCPU_ID);
+ vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
+ "Got exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s),\n",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+}
+
+void test_nested_state_expect_einval(struct kvm_vm *vm,
+ struct kvm_nested_state *state)
+{
+ test_nested_state_expect_errno(vm, state, EINVAL);
+}
+
+void test_nested_state_expect_efault(struct kvm_vm *vm,
+ struct kvm_nested_state *state)
+{
+ test_nested_state_expect_errno(vm, state, EFAULT);
+}
+
+void set_revision_id_for_vmcs12(struct kvm_nested_state *state,
+ u32 vmcs12_revision)
+{
+ /* Set revision_id in vmcs12 to vmcs12_revision. */
+ *(u32 *)(state->data) = vmcs12_revision;
+}
+
+void set_default_state(struct kvm_nested_state *state)
+{
+ memset(state, 0, sizeof(*state));
+ state->flags = KVM_STATE_NESTED_RUN_PENDING |
+ KVM_STATE_NESTED_GUEST_MODE;
+ state->format = 0;
+ state->size = sizeof(*state);
+}
+
+void set_default_vmx_state(struct kvm_nested_state *state, int size)
+{
+ memset(state, 0, size);
+ state->flags = KVM_STATE_NESTED_GUEST_MODE |
+ KVM_STATE_NESTED_RUN_PENDING |
+ KVM_STATE_NESTED_EVMCS;
+ state->format = 0;
+ state->size = size;
+ state->vmx.vmxon_pa = 0x1000;
+ state->vmx.vmcs_pa = 0x2000;
+ state->vmx.smm.flags = 0;
+ set_revision_id_for_vmcs12(state, VMCS12_REVISION);
+}
+
+void test_vmx_nested_state(struct kvm_vm *vm)
+{
+ /* Add a page for VMCS12. */
+ const int state_sz = sizeof(struct kvm_nested_state) + getpagesize();
+ struct kvm_nested_state *state =
+ (struct kvm_nested_state *)malloc(state_sz);
+
+ /* The format must be set to 0. 0 for VMX, 1 for SVM. */
+ set_default_vmx_state(state, state_sz);
+ state->format = 1;
+ test_nested_state_expect_einval(vm, state);
+
+ /*
+ * We cannot virtualize anything if the guest does not have VMX
+ * enabled.
+ */
+ set_default_vmx_state(state, state_sz);
+ test_nested_state_expect_einval(vm, state);
+
+ /*
+ * We cannot virtualize anything if the guest does not have VMX
+ * enabled. We expect KVM_SET_NESTED_STATE to return 0 if vmxon_pa
+ * is set to -1ull.
+ */
+ set_default_vmx_state(state, state_sz);
+ state->vmx.vmxon_pa = -1ull;
+ test_nested_state(vm, state);
+
+ /* Enable VMX in the guest CPUID. */
+ vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+ /* It is invalid to have vmxon_pa == -1ull and SMM flags non-zero. */
+ set_default_vmx_state(state, state_sz);
+ state->vmx.vmxon_pa = -1ull;
+ state->vmx.smm.flags = 1;
+ test_nested_state_expect_einval(vm, state);
+
+ /* It is invalid to have vmxon_pa == -1ull and vmcs_pa != -1ull. */
+ set_default_vmx_state(state, state_sz);
+ state->vmx.vmxon_pa = -1ull;
+ state->vmx.vmcs_pa = 0;
+ test_nested_state_expect_einval(vm, state);
+
+ /*
+ * Setting vmxon_pa == -1ull and vmcs_pa == -1ull exits early without
+ * setting the nested state.
+ */
+ set_default_vmx_state(state, state_sz);
+ state->vmx.vmxon_pa = -1ull;
+ state->vmx.vmcs_pa = -1ull;
+ test_nested_state(vm, state);
+
+ /* It is invalid to have vmxon_pa set to a non-page aligned address. */
+ set_default_vmx_state(state, state_sz);
+ state->vmx.vmxon_pa = 1;
+ test_nested_state_expect_einval(vm, state);
+
+ /*
+ * It is invalid to have KVM_STATE_NESTED_SMM_GUEST_MODE and
+ * KVM_STATE_NESTED_GUEST_MODE set together.
+ */
+ set_default_vmx_state(state, state_sz);
+ state->flags = KVM_STATE_NESTED_GUEST_MODE |
+ KVM_STATE_NESTED_RUN_PENDING;
+ state->vmx.smm.flags = KVM_STATE_NESTED_SMM_GUEST_MODE;
+ test_nested_state_expect_einval(vm, state);
+
+ /*
+ * It is invalid to have any of the SMM flags set besides:
+ * KVM_STATE_NESTED_SMM_GUEST_MODE
+ * KVM_STATE_NESTED_SMM_VMXON
+ */
+ set_default_vmx_state(state, state_sz);
+ state->vmx.smm.flags = ~(KVM_STATE_NESTED_SMM_GUEST_MODE |
+ KVM_STATE_NESTED_SMM_VMXON);
+ test_nested_state_expect_einval(vm, state);
+
+ /* Outside SMM, SMM flags must be zero. */
+ set_default_vmx_state(state, state_sz);
+ state->flags = 0;
+ state->vmx.smm.flags = KVM_STATE_NESTED_SMM_GUEST_MODE;
+ test_nested_state_expect_einval(vm, state);
+
+ /* Size must be large enough to fit kvm_nested_state and vmcs12. */
+ set_default_vmx_state(state, state_sz);
+ state->size = sizeof(*state);
+ test_nested_state(vm, state);
+
+ /* vmxon_pa cannot be the same address as vmcs_pa. */
+ set_default_vmx_state(state, state_sz);
+ state->vmx.vmxon_pa = 0;
+ state->vmx.vmcs_pa = 0;
+ test_nested_state_expect_einval(vm, state);
+
+ /* The revision id for vmcs12 must be VMCS12_REVISION. */
+ set_default_vmx_state(state, state_sz);
+ set_revision_id_for_vmcs12(state, 0);
+ test_nested_state_expect_einval(vm, state);
+
+ /*
+ * Test that if we leave nesting the state reflects that when we get
+ * it again.
+ */
+ set_default_vmx_state(state, state_sz);
+ state->vmx.vmxon_pa = -1ull;
+ state->vmx.vmcs_pa = -1ull;
+ state->flags = 0;
+ test_nested_state(vm, state);
+ vcpu_nested_state_get(vm, VCPU_ID, state);
+ TEST_ASSERT(state->size >= sizeof(*state) && state->size <= state_sz,
+ "Size must be between %d and %d. The size returned was %d.",
+ sizeof(*state), state_sz, state->size);
+ TEST_ASSERT(state->vmx.vmxon_pa == -1ull, "vmxon_pa must be -1ull.");
+ TEST_ASSERT(state->vmx.vmcs_pa == -1ull, "vmcs_pa must be -1ull.");
+
+ free(state);
+}
+
+int main(int argc, char *argv[])
+{
+ struct kvm_vm *vm;
+ struct kvm_nested_state state;
+ struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
+
+ if (!kvm_check_cap(KVM_CAP_NESTED_STATE)) {
+ printf("KVM_CAP_NESTED_STATE not available, skipping test\n");
+ exit(KSFT_SKIP);
+ }
+
+ /*
+ * AMD currently does not implement set_nested_state, so for now we
+ * just early out.
+ */
+ if (!(entry->ecx & CPUID_VMX)) {
+ fprintf(stderr, "nested VMX not enabled, skipping test\n");
+ exit(KSFT_SKIP);
+ }
+
+ vm = vm_create_default(VCPU_ID, 0, 0);
+
+ /* Passing a NULL kvm_nested_state causes a EFAULT. */
+ test_nested_state_expect_efault(vm, NULL);
+
+ /* 'size' cannot be smaller than sizeof(kvm_nested_state). */
+ set_default_state(&state);
+ state.size = 0;
+ test_nested_state_expect_einval(vm, &state);
+
+ /*
+ * Setting the flags 0xf fails the flags check. The only flags that
+ * can be used are:
+ * KVM_STATE_NESTED_GUEST_MODE
+ * KVM_STATE_NESTED_RUN_PENDING
+ * KVM_STATE_NESTED_EVMCS
+ */
+ set_default_state(&state);
+ state.flags = 0xf;
+ test_nested_state_expect_einval(vm, &state);
+
+ /*
+ * If KVM_STATE_NESTED_RUN_PENDING is set then
+ * KVM_STATE_NESTED_GUEST_MODE has to be set as well.
+ */
+ set_default_state(&state);
+ state.flags = KVM_STATE_NESTED_RUN_PENDING;
+ test_nested_state_expect_einval(vm, &state);
+
+ /*
+ * TODO: When SVM support is added for KVM_SET_NESTED_STATE
+ * add tests here to support it like VMX.
+ */
+ if (entry->ecx & CPUID_VMX)
+ test_vmx_nested_state(vm);
+
+ kvm_vm_free(vm);
+ return 0;
+}