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From:   Kechen Lu <kechenl@nvidia.com>
To:     <kvm@vger.kernel.org>, <pbonzini@redhat.com>
CC:     <seanjc@google.com>, <chao.gao@intel.com>, <vkuznets@redhat.com>,
        <somduttar@nvidia.com>, <kechenl@nvidia.com>,
        <linux-kernel@vger.kernel.org>
Subject: [RFC PATCH v4 7/7] KVM: selftests: Add tests for VM and vCPU cap KVM_CAP_X86_DISABLE_EXITS
Date:   Tue, 21 Jun 2022 17:49:24 -0700
Message-ID: <20220622004924.155191-8-kechenl@nvidia.com>
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Add tests for KVM cap KVM_CAP_X86_DISABLE_EXITS overriding flags
in VM and vCPU scope both works as expected.

Suggested-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Kechen Lu <kechenl@nvidia.com>
---
 tools/testing/selftests/kvm/.gitignore        |   1 +
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/include/x86_64/svm_util.h   |   1 +
 .../selftests/kvm/x86_64/disable_exits_test.c | 145 ++++++++++++++++++
 4 files changed, 148 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/x86_64/disable_exits_test.c

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index 4509a3a7eeae..2b50170db9b2 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -15,6 +15,7 @@
 /x86_64/cpuid_test
 /x86_64/cr4_cpuid_sync_test
 /x86_64/debug_regs
+/x86_64/disable_exits_test
 /x86_64/evmcs_test
 /x86_64/emulator_error_test
 /x86_64/fix_hypercall_test
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 22423c871ed6..de11d1f95700 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -115,6 +115,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/xen_shinfo_test
 TEST_GEN_PROGS_x86_64 += x86_64/xen_vmcall_test
 TEST_GEN_PROGS_x86_64 += x86_64/sev_migrate_tests
 TEST_GEN_PROGS_x86_64 += x86_64/amx_test
+TEST_GEN_PROGS_x86_64 += x86_64/disable_exits_test
 TEST_GEN_PROGS_x86_64 += access_tracking_perf_test
 TEST_GEN_PROGS_x86_64 += demand_paging_test
 TEST_GEN_PROGS_x86_64 += dirty_log_test
diff --git a/tools/testing/selftests/kvm/include/x86_64/svm_util.h b/tools/testing/selftests/kvm/include/x86_64/svm_util.h
index a25aabd8f5e7..d8cad1cff578 100644
--- a/tools/testing/selftests/kvm/include/x86_64/svm_util.h
+++ b/tools/testing/selftests/kvm/include/x86_64/svm_util.h
@@ -17,6 +17,7 @@
 #define CPUID_SVM		BIT_ULL(CPUID_SVM_BIT)
 
 #define SVM_EXIT_MSR		0x07c
+#define SVM_EXIT_HLT		0x078
 #define SVM_EXIT_VMMCALL	0x081
 
 struct svm_test_data {
diff --git a/tools/testing/selftests/kvm/x86_64/disable_exits_test.c b/tools/testing/selftests/kvm/x86_64/disable_exits_test.c
new file mode 100644
index 000000000000..2811b07e8885
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/disable_exits_test.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test per-VM and per-vCPU disable exits cap
+ *
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "svm_util.h"
+#include "vmx.h"
+#include "processor.h"
+
+#define VCPU_ID_1 0
+#define VCPU_ID_2 1
+
+static void guest_code_exits(void) {
+	asm volatile("sti; hlt; cli");
+}
+
+/* Set debug control for trapped instruction exiting to userspace */
+static void vcpu_set_debug_exit_userspace(struct kvm_vm *vm, int vcpu_id) {
+	struct kvm_guest_debug debug;
+	memset(&debug, 0, sizeof(debug));
+	debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_EXIT_USERSPACE;
+	vcpu_set_guest_debug(vm, vcpu_id, &debug);
+}
+
+static void test_vm_cap_disable_exits(void) {
+	struct kvm_enable_cap cap = {
+		.cap = KVM_CAP_X86_DISABLE_EXITS,
+		.args[0] = KVM_X86_DISABLE_EXITS_HLT|KVM_X86_DISABLE_EXITS_OVERRIDE,
+	};
+	struct kvm_vm *vm;
+	struct kvm_run *run;
+
+	/* Create VM */
+	vm = vm_create_without_vcpus(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES);
+
+	/* Test Case #1
+	 * Default without disabling HLT exits in VM scope
+	 */
+	vm_vcpu_add_default(vm, VCPU_ID_1, (void *)guest_code_exits);
+	vcpu_set_debug_exit_userspace(vm, VCPU_ID_1);
+	run = vcpu_state(vm, VCPU_ID_1);
+	vcpu_run(vm, VCPU_ID_1);
+	/* Exit reason should be HLT */
+	if (is_amd_cpu())
+		TEST_ASSERT(run->hw.hardware_exit_reason == SVM_EXIT_HLT,
+			"Got exit_reason other than HLT: 0x%llx\n",
+			run->hw.hardware_exit_reason);
+	else
+		TEST_ASSERT(run->hw.hardware_exit_reason == EXIT_REASON_HLT,
+			"Got exit_reason other than HLT: 0x%llx\n",
+			run->hw.hardware_exit_reason);
+
+	/* Test Case #2
+	 * Disabling HLT exits in VM scope
+	 */
+	vm_vcpu_add_default(vm, VCPU_ID_2, (void *)guest_code_exits);
+	vcpu_set_debug_exit_userspace(vm, VCPU_ID_2);
+	run = vcpu_state(vm, VCPU_ID_2);
+	/* Set VM scoped cap arg
+	 * KVM_X86_DISABLE_EXITS_HLT|KVM_X86_DISABLE_EXITS_OVERRIDE
+	 * after vCPUs creation so requiring override flag
+	 */
+	TEST_ASSERT(!vm_enable_cap(vm, &cap), "Failed to set KVM_CAP_X86_DISABLE_EXITS");
+	vcpu_run(vm, VCPU_ID_2);
+	/* Exit reason should not be HLT, would finish the guest
+	 * running and exit (e.g. SVM_EXIT_SHUTDOWN)
+	 */
+	if (is_amd_cpu())
+		TEST_ASSERT(run->hw.hardware_exit_reason != SVM_EXIT_HLT,
+			"Got exit_reason as HLT: 0x%llx\n",
+			run->hw.hardware_exit_reason);
+	else
+		TEST_ASSERT(run->hw.hardware_exit_reason != EXIT_REASON_HLT,
+			"Got exit_reason as HLT: 0x%llx\n",
+			run->hw.hardware_exit_reason);
+
+	kvm_vm_free(vm);
+}
+
+static void test_vcpu_cap_disable_exits(void) {
+	struct kvm_enable_cap cap = {
+		.cap = KVM_CAP_X86_DISABLE_EXITS,
+		.args[0] = KVM_X86_DISABLE_EXITS_HLT|KVM_X86_DISABLE_EXITS_OVERRIDE,
+	};
+	struct kvm_vm *vm;
+	struct kvm_run *run;
+
+	/* Create VM */
+	vm = vm_create_without_vcpus(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES);
+	vm_vcpu_add_default(vm, VCPU_ID_1, (void *)guest_code_exits);
+	vcpu_set_debug_exit_userspace(vm, VCPU_ID_1);
+	vm_vcpu_add_default(vm, VCPU_ID_2, (void *)guest_code_exits);
+	vcpu_set_debug_exit_userspace(vm, VCPU_ID_2);
+	/* Set vCPU 2 scoped cap arg
+	 * KVM_X86_DISABLE_EXITS_HLT|KVM_X86_DISABLE_EXITS_OVERRIDE
+	 */
+	TEST_ASSERT(!vcpu_enable_cap(vm, VCPU_ID_2, &cap), "Failed to set KVM_CAP_X86_DISABLE_EXITS");
+
+	/* Test Case #3
+	 * Default without disabling HLT exits in this vCPU 1
+	 */
+	run = vcpu_state(vm, VCPU_ID_1);
+	vcpu_run(vm, VCPU_ID_1);
+	/* Exit reason should be HLT */
+	if (is_amd_cpu())
+		TEST_ASSERT(run->hw.hardware_exit_reason == SVM_EXIT_HLT,
+			"Got exit_reason other than HLT: 0x%llx\n",
+			run->hw.hardware_exit_reason);
+	else
+		TEST_ASSERT(run->hw.hardware_exit_reason == EXIT_REASON_HLT,
+			"Got exit_reason other than HLT: 0x%llx\n",
+			run->hw.hardware_exit_reason);
+
+	/* Test Case #4
+	 * Disabling HLT exits in vCPU 2
+	 */
+	run = vcpu_state(vm, VCPU_ID_2);
+	vcpu_run(vm, VCPU_ID_2);
+	/* Exit reason should not be HLT, would finish the guest
+	 * running and exit (e.g. SVM_EXIT_SHUTDOWN)
+	 */
+	if (is_amd_cpu())
+		TEST_ASSERT(run->hw.hardware_exit_reason != SVM_EXIT_HLT,
+			"Got exit_reason as HLT: 0x%llx\n",
+			run->hw.hardware_exit_reason);
+	else
+		TEST_ASSERT(run->hw.hardware_exit_reason != EXIT_REASON_HLT,
+			"Got exit_reason as HLT: 0x%llx\n",
+			run->hw.hardware_exit_reason);
+
+	kvm_vm_free(vm);
+}
+
+int main(int argc, char *argv[])
+{
+	test_vm_cap_disable_exits();
+	test_vcpu_cap_disable_exits();
+	return 0;
+}
-- 
2.32.0