[PATCH] KVM: selftests: Skip tests that require EPT when it is not available

[David Matlack <dmatlack@google.com>]

Skip selftests that require EPT support in the VM when it is not
available. For example, if running on a machine where kvm_intel.ept=N
since KVM does not offer EPT support to guests if EPT is not supported
on the host.

This commit causes vmx_dirty_log_test to be skipped instead of failing
on hosts where kvm_intel.ept=N.

Signed-off-by: David Matlack <dmatlack@google.com>
---
 .../selftests/kvm/include/x86_64/vmx.h        |  1 +
 tools/testing/selftests/kvm/lib/x86_64/vmx.c  | 20 +++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h
index 99fa1410964c..790c6d1ecb34 100644
--- a/tools/testing/selftests/kvm/include/x86_64/vmx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h
@@ -617,6 +617,7 @@ void nested_map_memslot(struct vmx_pages *vmx, struct kvm_vm *vm,
 			uint32_t memslot);
 void nested_identity_map_1g(struct vmx_pages *vmx, struct kvm_vm *vm,
 			    uint64_t addr, uint64_t size);
+bool kvm_vm_has_ept(struct kvm_vm *vm);
 void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm,
 		  uint32_t eptp_memslot);
 void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm);
diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
index 80a568c439b8..d21049c38fc5 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
@@ -5,6 +5,8 @@
  * Copyright (C) 2018, Google LLC.
  */
 
+#include <asm/msr-index.h>
+
 #include "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"
@@ -542,9 +544,27 @@ void nested_identity_map_1g(struct vmx_pages *vmx, struct kvm_vm *vm,
 	__nested_map(vmx, vm, addr, addr, size, PG_LEVEL_1G);
 }
 
+bool kvm_vm_has_ept(struct kvm_vm *vm)
+{
+	struct kvm_vcpu *vcpu;
+	uint64_t ctrl;
+
+	vcpu = list_first_entry(&vm->vcpus, struct kvm_vcpu, list);
+	TEST_ASSERT(vcpu, "Cannot determine EPT support without vCPUs.\n");
+
+	ctrl = vcpu_get_msr(vcpu, MSR_IA32_VMX_TRUE_PROCBASED_CTLS) >> 32;
+	if (!(ctrl & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS))
+		return false;
+
+	ctrl = vcpu_get_msr(vcpu, MSR_IA32_VMX_PROCBASED_CTLS2) >> 32;
+	return ctrl & SECONDARY_EXEC_ENABLE_EPT;
+}
+
 void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm,
 		  uint32_t eptp_memslot)
 {
+	TEST_REQUIRE(kvm_vm_has_ept(vm));
+
 	vmx->eptp = (void *)vm_vaddr_alloc_page(vm);
 	vmx->eptp_hva = addr_gva2hva(vm, (uintptr_t)vmx->eptp);
 	vmx->eptp_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->eptp);

base-commit: 372d07084593dc7a399bf9bee815711b1fb1bcf2
prerequisite-patch-id: 2e3661ba8856c29b769499bac525b6943d9284b8
prerequisite-patch-id: 93031262de7b1f7fab1ad31ea5d6ef812c139179
-- 
2.37.3.998.g577e59143f-goog