Re: [RFC PATCH v4 7/7] KVM: selftests: Add tests for VM and vCPU cap KVM_CAP_X86_DISABLE_EXITS
From: Huang, Shaoqin
Date: Wed Jun 22 2022 - 02:44:47 EST
On 6/22/2022 8:49 AM, Kechen Lu wrote:
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@xxxxxxxxx>
Signed-off-by: Kechen Lu <kechenl@xxxxxxxxxx>
---
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
There has other people add the SVM_EXIT_HLT in the kvm/queue, so you may
not need to add it here.
#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) {
nit: you should make the code style consistent, please use the format:
function()
{
}
+ 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,
^
nit: a space is much more clear here
+ };
+ 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);
I think you can add more vcpu here to make sure after disabling HLT
exits in VM scope here, every vcpu will not exit due to the HLT.
+ /* 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;
+}