[RFC] selftests: kvm: add a selftest for SMM

From: Vitaly Kuznetsov
Date: Wed Apr 10 2019 - 05:38:40 EST

Early RFC, based on state_test.

Add a simplistic test for SMM. Currently it fails with
"Unexpected result from KVM_SET_NESTED_STATE" even when a patch fixing
rsm after VMXON is added. There's likey some other issue in nested
save/restore when SMM os on.

The test implements its own sync between the guest and the host as using
our ucall library seems to be too cumbersome: SMI handler is happening in
real-address mode.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
tools/testing/selftests/kvm/Makefile | 1 +
.../selftests/kvm/include/x86_64/processor.h | 27 +++
tools/testing/selftests/kvm/x86_64/smm_test.c | 159 ++++++++++++++++++
3 files changed, 187 insertions(+)
create mode 100644 tools/testing/selftests/kvm/x86_64/smm_test.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 3c1f4bdf9000..257955593cdf 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -17,6 +17,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/state_test
TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
TEST_GEN_PROGS_x86_64 += x86_64/vmx_close_while_nested_test
+TEST_GEN_PROGS_x86_64 += x86_64/smm_test
TEST_GEN_PROGS_x86_64 += dirty_log_test
TEST_GEN_PROGS_x86_64 += clear_dirty_log_test

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index e2884c2b81ff..6063d5b2f356 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -778,6 +778,33 @@ void vcpu_set_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index,
#define MSR_IA32_APICBASE_ENABLE (1<<11)
#define MSR_IA32_APICBASE_BASE (0xfffff<<12)

+#define APIC_BASE_MSR 0x800
+#define X2APIC_ENABLE (1UL << 10)
+#define APIC_ICR 0x300
+#define APIC_DEST_SELF 0x40000
+#define APIC_DEST_ALLINC 0x80000
+#define APIC_DEST_ALLBUT 0xC0000
+#define APIC_ICR_RR_MASK 0x30000
+#define APIC_ICR_RR_INVALID 0x00000
+#define APIC_ICR_RR_INPROG 0x10000
+#define APIC_ICR_RR_VALID 0x20000
+#define APIC_INT_LEVELTRIG 0x08000
+#define APIC_INT_ASSERT 0x04000
+#define APIC_ICR_BUSY 0x01000
+#define APIC_DEST_LOGICAL 0x00800
+#define APIC_DEST_PHYSICAL 0x00000
+#define APIC_DM_FIXED 0x00000
+#define APIC_DM_FIXED_MASK 0x00700
+#define APIC_DM_LOWEST 0x00100
+#define APIC_DM_SMI 0x00200
+#define APIC_DM_REMRD 0x00300
+#define APIC_DM_NMI 0x00400
+#define APIC_DM_INIT 0x00500
+#define APIC_DM_STARTUP 0x00600
+#define APIC_DM_EXTINT 0x00700
+#define APIC_VECTOR_MASK 0x000FF
+#define APIC_ICR2 0x310
+
#define MSR_IA32_TSCDEADLINE 0x000006e0

#define MSR_IA32_UCODE_WRITE 0x00000079
diff --git a/tools/testing/selftests/kvm/x86_64/smm_test.c b/tools/testing/selftests/kvm/x86_64/smm_test.c
new file mode 100644
index 000000000000..3452b592588a
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/smm_test.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018, Red Hat, Inc.
+ *
+ * Tests for SMM.
+ */
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+
+#include "kvm_util.h"
+
+#include "vmx.h"
+
+#define VCPU_ID 1
+
+#define PAGE_SIZE 4096
+
+#define SMRAM_SIZE (16 * PAGE_SIZE)
+#define SMRAM_GPA 0x1000000
+#define SMRAM_STAGE 0xfe
+
+#define STR(x) #x
+#define XSTR(s) STR(s)
+
+#define SYNC_PORT 0xe
+#define DONE 0xff
+
+/*
+ * This is compiled as normal 64-bit code, however, SMI handler is executed
+ * in real-address mode. To stay simple we're limiting ourselves to a mode
+ * independent subset of asm here.
+ * SMI handler always report back fixed stage SMRAM_STAGE.
+ */
+void smi_handler(void)
+{
+ asm volatile("mov $" XSTR(SMRAM_STAGE) ", %al \n"
+ "in $" XSTR(SYNC_PORT) ", %al \n"
+ "rsm \n");
+}
+/* This should change if the code above changes in length */
+#define SMI_HANDLER_SIZE 6
+
+void sync_with_host(uint64_t phase)
+{
+ asm volatile("in $" XSTR(SYNC_PORT)", %%al \n"
+ : : "a" (phase));
+}
+
+void self_smi(void)
+{
+ wrmsr(APIC_BASE_MSR + (APIC_ICR >> 4),
+ APIC_DEST_SELF | APIC_INT_ASSERT | APIC_DM_SMI);
+}
+
+void guest_code(struct vmx_pages *vmx_pages)
+{
+ uint64_t apicbase = rdmsr(MSR_IA32_APICBASE);
+
+ sync_with_host(1);
+
+ wrmsr(MSR_IA32_APICBASE, apicbase | X2APIC_ENABLE);
+
+ sync_with_host(2);
+
+ self_smi();
+
+ sync_with_host(4);
+
+ if (vmx_pages) {
+ GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
+
+ sync_with_host(5);
+
+ self_smi();
+
+ sync_with_host(7);
+ }
+
+ sync_with_host(DONE);
+}
+
+int main(int argc, char *argv[])
+{
+ struct vmx_pages *vmx_pages = NULL;
+ vm_vaddr_t vmx_pages_gva = 0;
+
+ struct kvm_regs regs;
+ struct kvm_vm *vm;
+ struct kvm_run *run;
+ struct kvm_x86_state *state;
+ int stage, stage_reported;
+
+ /* Create VM */
+ vm = vm_create_default(VCPU_ID, 0, guest_code);
+
+ vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+ run = vcpu_state(vm, VCPU_ID);
+
+ vcpu_regs_get(vm, VCPU_ID, &regs);
+
+ vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, SMRAM_GPA,
+ 1 << 16 | 1, SMRAM_SIZE/PAGE_SIZE, 0);
+
+ memset(addr_gpa2hva(vm, SMRAM_GPA), 0x0, SMRAM_SIZE);
+ memcpy(addr_gpa2hva(vm, SMRAM_GPA) + 0x8000, smi_handler,
+ SMI_HANDLER_SIZE);
+
+ vcpu_set_msr(vm, VCPU_ID, MSR_IA32_SMBASE, SMRAM_GPA);
+
+ if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
+ vmx_pages = vcpu_alloc_vmx(vm, &vmx_pages_gva);
+ vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
+ } else {
+ printf("will skip SMM test with VMX enabled\n");
+ vcpu_args_set(vm, VCPU_ID, 1, 0);
+ }
+
+ for (stage = 1;; stage++) {
+ _vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+ "Stage %d: unexpected exit reason: %u (%s),\n",
+ stage, run->exit_reason,
+ exit_reason_str(run->exit_reason));
+
+ memset(&regs, 0, sizeof(regs));
+ vcpu_regs_get(vm, VCPU_ID, &regs);
+
+ stage_reported = regs.rax & 0xff;
+
+ if (stage_reported == DONE)
+ goto done;
+
+ TEST_ASSERT(stage_reported == stage ||
+ stage_reported == SMRAM_STAGE,
+ "Unexpected stage: #%x, got %x",
+ stage, stage_reported);
+
+ /* This piece of code needs sharing with state_test/evmcs_test */
+ state = vcpu_save_state(vm, VCPU_ID);
+ kvm_vm_release(vm);
+ kvm_vm_restart(vm, O_RDWR);
+ vm_vcpu_add(vm, VCPU_ID, 0, 0);
+ vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+ vcpu_load_state(vm, VCPU_ID, state);
+ run = vcpu_state(vm, VCPU_ID);
+ free(state);
+ }
+
+done:
+ kvm_vm_free(vm);
+}
--
2.20.1