[PATCH 0/3] kvm: selftests: fixes for vmx_set_nested_state_test

[PATCH 0/3] kvm: selftests: fixes for vmx_set_nested_state_test

[Paolo Bonzini]

The vmx_set_nested_state_test test is failing in the top of the tree, due
to the change in KVM_STATE_NESTED_EVMCS semantics from commit 323d73a8ecad
("KVM: nVMX: Change KVM_STATE_NESTED_EVMCS to signal vmcs12 is copied
from eVMCS", 2019-06-26).  The expected behavior of the kernel has changed
slightly and the test should be changed to match the fix in the kernel.

Paolo

Paolo Bonzini (3):
  selftests: kvm: do not try running the VM in vmx_set_nested_state_test
  selftests: kvm: provide common function to enable eVMCS
  selftests: kvm: fix vmx_set_nested_state_test

 tools/testing/selftests/kvm/include/evmcs.h        |  2 ++
 tools/testing/selftests/kvm/lib/x86_64/vmx.c       | 20 ++++++++++++++
 tools/testing/selftests/kvm/x86_64/evmcs_test.c    | 15 ++--------
 tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c  | 12 +++-----
 .../kvm/x86_64/vmx_set_nested_state_test.c         | 32 ++++++++++------------
 5 files changed, 42 insertions(+), 39 deletions(-)

-- 
1.8.3.1

[PATCH 1/3] selftests: kvm: do not try running the VM in vmx_set_nested_state_test

[Paolo Bonzini]

This test is only covering various edge cases of the
KVM_SET_NESTED_STATE ioctl.  Running the VM does not really
add anything.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 .../selftests/kvm/x86_64/vmx_set_nested_state_test.c      | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c b/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
index ed7218d166da..a99fc66dafeb 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
@@ -27,22 +27,13 @@
 
 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);
@@ -50,12 +41,6 @@ void test_nested_state_expect_errno(struct kvm_vm *vm,
 		"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,
-- 
1.8.3.1

[PATCH 2/3] selftests: kvm: provide common function to enable eVMCS

[Paolo Bonzini]

There are two tests already enabling eVMCS and a third is coming.
Add a function that enables the capability and tests the result.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 tools/testing/selftests/kvm/include/evmcs.h       |  2 ++
 tools/testing/selftests/kvm/lib/x86_64/vmx.c      | 20 ++++++++++++++++++++
 tools/testing/selftests/kvm/x86_64/evmcs_test.c   | 15 ++-------------
 tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 12 ++++--------
 4 files changed, 28 insertions(+), 21 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/evmcs.h b/tools/testing/selftests/kvm/include/evmcs.h
index 4059014d93ea..4912d23844bc 100644
--- a/tools/testing/selftests/kvm/include/evmcs.h
+++ b/tools/testing/selftests/kvm/include/evmcs.h
@@ -220,6 +220,8 @@ struct hv_enlightened_vmcs {
 struct hv_enlightened_vmcs *current_evmcs;
 struct hv_vp_assist_page *current_vp_assist;
 
+int vcpu_enable_evmcs(struct kvm_vm *vm, int vcpu_id);
+
 static inline int enable_vp_assist(uint64_t vp_assist_pa, void *vp_assist)
 {
 	u64 val = (vp_assist_pa & HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_MASK) |
diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
index 204f847bd065..9cef0455b819 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
@@ -12,6 +12,26 @@
 
 bool enable_evmcs;
 
+int vcpu_enable_evmcs(struct kvm_vm *vm, int vcpu_id)
+{
+	uint16_t evmcs_ver;
+
+	struct kvm_enable_cap enable_evmcs_cap = {
+		.cap = KVM_CAP_HYPERV_ENLIGHTENED_VMCS,
+		 .args[0] = (unsigned long)&evmcs_ver
+	};
+
+	vcpu_ioctl(vm, vcpu_id, KVM_ENABLE_CAP, &enable_evmcs_cap);
+
+	/* KVM should return supported EVMCS version range */
+	TEST_ASSERT(((evmcs_ver >> 8) >= (evmcs_ver & 0xff)) &&
+		    (evmcs_ver & 0xff) > 0,
+		    "Incorrect EVMCS version range: %x:%x\n",
+		    evmcs_ver & 0xff, evmcs_ver >> 8);
+
+	return evmcs_ver;
+}
+
 /* Allocate memory regions for nested VMX tests.
  *
  * Input Args:
diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
index f95c08343b48..92915e6408e7 100644
--- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
@@ -79,11 +79,6 @@ int main(int argc, char *argv[])
 	struct kvm_x86_state *state;
 	struct ucall uc;
 	int stage;
-	uint16_t evmcs_ver;
-	struct kvm_enable_cap enable_evmcs_cap = {
-		.cap = KVM_CAP_HYPERV_ENLIGHTENED_VMCS,
-		 .args[0] = (unsigned long)&evmcs_ver
-	};
 
 	/* Create VM */
 	vm = vm_create_default(VCPU_ID, 0, guest_code);
@@ -96,13 +91,7 @@ int main(int argc, char *argv[])
 		exit(KSFT_SKIP);
 	}
 
-	vcpu_ioctl(vm, VCPU_ID, KVM_ENABLE_CAP, &enable_evmcs_cap);
-
-	/* KVM should return supported EVMCS version range */
-	TEST_ASSERT(((evmcs_ver >> 8) >= (evmcs_ver & 0xff)) &&
-		    (evmcs_ver & 0xff) > 0,
-		    "Incorrect EVMCS version range: %x:%x\n",
-		    evmcs_ver & 0xff, evmcs_ver >> 8);
+	vcpu_enable_evmcs(vm, VCPU_ID);
 
 	run = vcpu_state(vm, VCPU_ID);
 
@@ -146,7 +135,7 @@ int main(int argc, char *argv[])
 		kvm_vm_restart(vm, O_RDWR);
 		vm_vcpu_add(vm, VCPU_ID);
 		vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
-		vcpu_ioctl(vm, VCPU_ID, KVM_ENABLE_CAP, &enable_evmcs_cap);
+		vcpu_enable_evmcs(vm, VCPU_ID);
 		vcpu_load_state(vm, VCPU_ID, state);
 		run = vcpu_state(vm, VCPU_ID);
 		free(state);
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
index f72b3043db0e..ee59831fbc98 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
@@ -18,6 +18,7 @@
 #include "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"
+#include "vmx.h"
 
 #define VCPU_ID 0
 
@@ -106,12 +107,7 @@ int main(int argc, char *argv[])
 {
 	struct kvm_vm *vm;
 	int rv;
-	uint16_t evmcs_ver;
 	struct kvm_cpuid2 *hv_cpuid_entries;
-	struct kvm_enable_cap enable_evmcs_cap = {
-		.cap = KVM_CAP_HYPERV_ENLIGHTENED_VMCS,
-		 .args[0] = (unsigned long)&evmcs_ver
-	};
 
 	/* Tell stdout not to buffer its content */
 	setbuf(stdout, NULL);
@@ -136,14 +132,14 @@ int main(int argc, char *argv[])
 
 	free(hv_cpuid_entries);
 
-	rv = _vcpu_ioctl(vm, VCPU_ID, KVM_ENABLE_CAP, &enable_evmcs_cap);
-
-	if (rv) {
+	if (!kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
 		fprintf(stderr,
 			"Enlightened VMCS is unsupported, skip related test\n");
 		goto vm_free;
 	}
 
+	vcpu_enable_evmcs(vm, VCPU_ID);
+
 	hv_cpuid_entries = kvm_get_supported_hv_cpuid(vm);
 	if (!hv_cpuid_entries)
 		return 1;
-- 
1.8.3.1

[PATCH 3/3] selftests: kvm: fix vmx_set_nested_state_test

[Paolo Bonzini]

vmx_set_nested_state_test is trying to use the KVM_STATE_NESTED_EVMCS without
enabling enlightened VMCS first.  Correct the outcome of the test, and actually
test that it succeeds after the capability is enabled.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 .../selftests/kvm/x86_64/vmx_set_nested_state_test.c    | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c b/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
index a99fc66dafeb..853e370e8a39 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c
@@ -25,6 +25,8 @@
 #define VMCS12_REVISION 0x11e57ed0
 #define VCPU_ID 5
 
+bool have_evmcs;
+
 void test_nested_state(struct kvm_vm *vm, struct kvm_nested_state *state)
 {
 	vcpu_nested_state_set(vm, VCPU_ID, state, false);
@@ -75,8 +77,9 @@ 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;
+			KVM_STATE_NESTED_RUN_PENDING;
+	if (have_evmcs)
+		state->flags |= KVM_STATE_NESTED_EVMCS;
 	state->format = 0;
 	state->size = size;
 	state->hdr.vmx.vmxon_pa = 0x1000;
@@ -126,13 +129,19 @@ void test_vmx_nested_state(struct kvm_vm *vm)
 	/*
 	 * Setting vmxon_pa == -1ull and vmcs_pa == -1ull exits early without
 	 * setting the nested state but flags other than eVMCS must be clear.
+	 * The eVMCS flag can be set if the enlightened VMCS capability has
+	 * been enabled.
 	 */
 	set_default_vmx_state(state, state_sz);
 	state->hdr.vmx.vmxon_pa = -1ull;
 	state->hdr.vmx.vmcs12_pa = -1ull;
 	test_nested_state_expect_einval(vm, state);
 
-	state->flags = KVM_STATE_NESTED_EVMCS;
+	state->flags &= KVM_STATE_NESTED_EVMCS;
+	if (have_evmcs) {
+		test_nested_state_expect_einval(vm, state);
+		vcpu_enable_evmcs(vm, VCPU_ID);
+	}
 	test_nested_state(vm, state);
 
 	/* It is invalid to have vmxon_pa == -1ull and SMM flags non-zero. */
@@ -217,6 +226,8 @@ int main(int argc, char *argv[])
 	struct kvm_nested_state state;
 	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
 
+	have_evmcs = kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS);
+
 	if (!kvm_check_cap(KVM_CAP_NESTED_STATE)) {
 		printf("KVM_CAP_NESTED_STATE not available, skipping test\n");
 		exit(KSFT_SKIP);
-- 
1.8.3.1