[PATCH 0/3] kvm: selftests fixes and a new smm_test

[PATCH 0/3] kvm: selftests fixes and a new smm_test

[Paolo Bonzini]

It turns out that the remaining issue in smm_test was in the test itself.
Here is the result...

Paolo

Paolo Bonzini (2):
  selftests: kvm/evmcs_test: complete I/O before migrating guest state
  selftests: kvm: fix for compilers that do not support -no-pie

Vitaly Kuznetsov (1):
  selftests: kvm: add a selftest for SMM

 tools/testing/selftests/kvm/Makefile               |   9 +-
 .../selftests/kvm/include/x86_64/processor.h       |  27 ++++
 tools/testing/selftests/kvm/lib/kvm_util.c         |   5 +
 tools/testing/selftests/kvm/lib/x86_64/processor.c |  20 ++-
 tools/testing/selftests/kvm/x86_64/evmcs_test.c    |   5 +-
 tools/testing/selftests/kvm/x86_64/smm_test.c      | 157 +++++++++++++++++++++
 tools/testing/selftests/kvm/x86_64/state_test.c    |  15 +-
 7 files changed, 215 insertions(+), 23 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/x86_64/smm_test.c

-- 
1.8.3.1

[PATCH 1/3] selftests: kvm/evmcs_test: complete I/O before migrating guest state

[Paolo Bonzini]

Starting state migration after an IO exit without first completing IO
may result in test failures.  We already have two tests that need this
(this patch in fact fixes evmcs_test, similar to what was fixed for
state_test in commit 0f73bbc851ed, "KVM: selftests: complete IO before
migrating guest state", 2019-03-13) and a third is coming.  So, move the
code to vcpu_save_state, and while at it do not access register state
until after I/O is complete.
---
 tools/testing/selftests/kvm/lib/kvm_util.c         |  5 +++++
 tools/testing/selftests/kvm/lib/x86_64/processor.c |  8 ++++++++
 tools/testing/selftests/kvm/x86_64/evmcs_test.c    |  5 +++--
 tools/testing/selftests/kvm/x86_64/state_test.c    | 15 +--------------
 4 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index efa0aad8b3c6..4ca96b228e46 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -91,6 +91,11 @@ static void vm_open(struct kvm_vm *vm, int perm, unsigned long type)
 	if (vm->kvm_fd < 0)
 		exit(KSFT_SKIP);
 
+	if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) {
+		fprintf(stderr, "immediate_exit not available, skipping test\n");
+		exit(KSFT_SKIP);
+	}
+
 	vm->fd = ioctl(vm->kvm_fd, KVM_CREATE_VM, type);
 	TEST_ASSERT(vm->fd >= 0, "KVM_CREATE_VM ioctl failed, "
 		"rc: %i errno: %i", vm->fd, errno);
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index f28127f4a3af..b363c9611bd6 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -1030,6 +1030,14 @@ struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid)
 			    nested_size, sizeof(state->nested_));
 	}
 
+	/*
+	 * When KVM exits to userspace with KVM_EXIT_IO, KVM guarantees
+	 * guest state is consistent only after userspace re-enters the
+	 * kernel with KVM_RUN.  Complete IO prior to migrating state
+	 * to a new VM.
+	 */
+	vcpu_run_complete_io(vm, vcpuid);
+
 	nmsrs = kvm_get_num_msrs(vm);
 	list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
 	list->nmsrs = nmsrs;
diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
index c49c2a28b0eb..36669684eca5 100644
--- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
@@ -123,8 +123,6 @@ int main(int argc, char *argv[])
 			    stage, run->exit_reason,
 			    exit_reason_str(run->exit_reason));
 
-		memset(&regs1, 0, sizeof(regs1));
-		vcpu_regs_get(vm, VCPU_ID, &regs1);
 		switch (get_ucall(vm, VCPU_ID, &uc)) {
 		case UCALL_ABORT:
 			TEST_ASSERT(false, "%s at %s:%d", (const char *)uc.args[0],
@@ -144,6 +142,9 @@ int main(int argc, char *argv[])
 			    stage, (ulong)uc.args[1]);
 
 		state = vcpu_save_state(vm, VCPU_ID);
+		memset(&regs1, 0, sizeof(regs1));
+		vcpu_regs_get(vm, VCPU_ID, &regs1);
+
 		kvm_vm_release(vm);
 
 		/* Restore state in a new VM.  */
diff --git a/tools/testing/selftests/kvm/x86_64/state_test.c b/tools/testing/selftests/kvm/x86_64/state_test.c
index 30f75856cf39..e0a3c0204b7c 100644
--- a/tools/testing/selftests/kvm/x86_64/state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/state_test.c
@@ -134,11 +134,6 @@ int main(int argc, char *argv[])
 
 	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
 
-	if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) {
-		fprintf(stderr, "immediate_exit not available, skipping test\n");
-		exit(KSFT_SKIP);
-	}
-
 	/* Create VM */
 	vm = vm_create_default(VCPU_ID, 0, guest_code);
 	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
@@ -179,18 +174,10 @@ int main(int argc, char *argv[])
 			    uc.args[1] == stage, "Unexpected register values vmexit #%lx, got %lx",
 			    stage, (ulong)uc.args[1]);
 
-		/*
-		 * When KVM exits to userspace with KVM_EXIT_IO, KVM guarantees
-		 * guest state is consistent only after userspace re-enters the
-		 * kernel with KVM_RUN.  Complete IO prior to migrating state
-		 * to a new VM.
-		 */
-		vcpu_run_complete_io(vm, VCPU_ID);
-
+		state = vcpu_save_state(vm, VCPU_ID);
 		memset(&regs1, 0, sizeof(regs1));
 		vcpu_regs_get(vm, VCPU_ID, &regs1);
 
-		state = vcpu_save_state(vm, VCPU_ID);
 		kvm_vm_release(vm);
 
 		/* Restore state in a new VM.  */
-- 
1.8.3.1

Re: [PATCH 1/3] selftests: kvm/evmcs_test: complete I/O before migrating guest state

[Andrew Jones]

On Thu, Apr 11, 2019 at 06:48:26PM +0200, Paolo Bonzini wrote:
> Starting state migration after an IO exit without first completing IO
> may result in test failures.  We already have two tests that need this
> (this patch in fact fixes evmcs_test, similar to what was fixed for
> state_test in commit 0f73bbc851ed, "KVM: selftests: complete IO before
> migrating guest state", 2019-03-13) and a third is coming.  So, move the
> code to vcpu_save_state, and while at it do not access register state
> until after I/O is complete.
> ---
>  tools/testing/selftests/kvm/lib/kvm_util.c         |  5 +++++
>  tools/testing/selftests/kvm/lib/x86_64/processor.c |  8 ++++++++
>  tools/testing/selftests/kvm/x86_64/evmcs_test.c    |  5 +++--
>  tools/testing/selftests/kvm/x86_64/state_test.c    | 15 +--------------
>  4 files changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index efa0aad8b3c6..4ca96b228e46 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -91,6 +91,11 @@ static void vm_open(struct kvm_vm *vm, int perm, unsigned long type)
>  	if (vm->kvm_fd < 0)
>  		exit(KSFT_SKIP);
>  
> +	if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) {
> +		fprintf(stderr, "immediate_exit not available, skipping test\n");
> +		exit(KSFT_SKIP);
> +	}
> +
>  	vm->fd = ioctl(vm->kvm_fd, KVM_CREATE_VM, type);
>  	TEST_ASSERT(vm->fd >= 0, "KVM_CREATE_VM ioctl failed, "
>  		"rc: %i errno: %i", vm->fd, errno);
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> index f28127f4a3af..b363c9611bd6 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> @@ -1030,6 +1030,14 @@ struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid)
>  			    nested_size, sizeof(state->nested_));
>  	}
>  
> +	/*
> +	 * When KVM exits to userspace with KVM_EXIT_IO, KVM guarantees
> +	 * guest state is consistent only after userspace re-enters the
> +	 * kernel with KVM_RUN.  Complete IO prior to migrating state
> +	 * to a new VM.
> +	 */
> +	vcpu_run_complete_io(vm, vcpuid);
> +

Since the need for IO completion also affects MMIO exits and there's no
reason to believe that vcpu_save_state() will always be called after
an IO exit, then shouldn't we instead put this in get_ucall()?

diff --git a/tools/testing/selftests/kvm/lib/ucall.c b/tools/testing/selftests/kvm/lib/ucall.c
index a2ab38be2f47..e8c6f2741ce7 100644
--- a/tools/testing/selftests/kvm/lib/ucall.c
+++ b/tools/testing/selftests/kvm/lib/ucall.c
@@ -132,6 +132,7 @@ uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc)
        if (ucall_type == UCALL_PIO && run->exit_reason == KVM_EXIT_IO &&
            run->io.port == UCALL_PIO_PORT) {
                struct kvm_regs regs;
+               vcpu_run_complete_io(vm, vcpu_id);
                vcpu_regs_get(vm, vcpu_id, &regs);
                memcpy(uc, addr_gva2hva(vm, (vm_vaddr_t)regs.rdi), sizeof(*uc));
                return uc->cmd;
@@ -144,6 +145,7 @@ uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc)
                            "Unexpected ucall exit mmio address access");
                gva = *(vm_vaddr_t *)run->mmio.data;
                memcpy(uc, addr_gva2hva(vm, gva), sizeof(*uc));
+               vcpu_run_complete_io(vm, vcpu_id);
        }
 
        return uc->cmd;



>  	nmsrs = kvm_get_num_msrs(vm);
>  	list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
>  	list->nmsrs = nmsrs;
> diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
> index c49c2a28b0eb..36669684eca5 100644
> --- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
> @@ -123,8 +123,6 @@ int main(int argc, char *argv[])
>  			    stage, run->exit_reason,
>  			    exit_reason_str(run->exit_reason));
>  
> -		memset(&regs1, 0, sizeof(regs1));
> -		vcpu_regs_get(vm, VCPU_ID, &regs1);
>  		switch (get_ucall(vm, VCPU_ID, &uc)) {
>  		case UCALL_ABORT:
>  			TEST_ASSERT(false, "%s at %s:%d", (const char *)uc.args[0],
> @@ -144,6 +142,9 @@ int main(int argc, char *argv[])
>  			    stage, (ulong)uc.args[1]);
>  
>  		state = vcpu_save_state(vm, VCPU_ID);
> +		memset(&regs1, 0, sizeof(regs1));
> +		vcpu_regs_get(vm, VCPU_ID, &regs1);
> +

We would still need this change to get the vcpu_regs_get() below the
get_ucall().

>  		kvm_vm_release(vm);
>  
>  		/* Restore state in a new VM.  */
> diff --git a/tools/testing/selftests/kvm/x86_64/state_test.c b/tools/testing/selftests/kvm/x86_64/state_test.c
> index 30f75856cf39..e0a3c0204b7c 100644
> --- a/tools/testing/selftests/kvm/x86_64/state_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/state_test.c
> @@ -134,11 +134,6 @@ int main(int argc, char *argv[])
>  
>  	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
>  
> -	if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) {
> -		fprintf(stderr, "immediate_exit not available, skipping test\n");
> -		exit(KSFT_SKIP);
> -	}
> -
>  	/* Create VM */
>  	vm = vm_create_default(VCPU_ID, 0, guest_code);
>  	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
> @@ -179,18 +174,10 @@ int main(int argc, char *argv[])
>  			    uc.args[1] == stage, "Unexpected register values vmexit #%lx, got %lx",
>  			    stage, (ulong)uc.args[1]);
>  
> -		/*
> -		 * When KVM exits to userspace with KVM_EXIT_IO, KVM guarantees
> -		 * guest state is consistent only after userspace re-enters the
> -		 * kernel with KVM_RUN.  Complete IO prior to migrating state
> -		 * to a new VM.
> -		 */
> -		vcpu_run_complete_io(vm, VCPU_ID);
> -
> +		state = vcpu_save_state(vm, VCPU_ID);
>  		memset(&regs1, 0, sizeof(regs1));
>  		vcpu_regs_get(vm, VCPU_ID, &regs1);
>  
> -		state = vcpu_save_state(vm, VCPU_ID);
>  		kvm_vm_release(vm);
>  
>  		/* Restore state in a new VM.  */
> -- 
> 1.8.3.1
> 
>

Thanks,
drew 

[PATCH 2/3] selftests: kvm: fix for compilers that do not support -no-pie

[Paolo Bonzini]

-no-pie was added to GCC at the same time as their configuration option
--enable-default-pie.  Compilers that were built before do not have
-no-pie, but they also do not need it.  Detect the option at build
time.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 tools/testing/selftests/kvm/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 7514fcea91a7..2d2e10b219d5 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -1,3 +1,5 @@
+include ../../../../scripts/Kbuild.include
+
 all:
 
 top_srcdir = ../../../..
@@ -30,7 +32,11 @@ INSTALL_HDR_PATH = $(top_srcdir)/usr
 LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
 LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include
 CFLAGS += -O2 -g -std=gnu99 -fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -Iinclude/$(UNAME_M) -I..
-LDFLAGS += -pthread -no-pie
+
+no-pie-option := $(call try-run, echo 'int main() { return 0; }' | \
+        $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -no-pie -x c - -o "$$TMP", -no-pie)
+
+LDFLAGS += -pthread $(no-pie-option)
 
 # After inclusion, $(OUTPUT) is defined and
 # $(TEST_GEN_PROGS) starts with $(OUTPUT)/
-- 
1.8.3.1

[PATCH 3/3] selftests: kvm: add a selftest for SMM

[Paolo Bonzini]

From: Vitaly Kuznetsov <vkuznets@redhat.com>

Add a simple test for SMM, based on VMX.  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.

This patch also fixes KVM_SET_NESTED_STATE to happen after
KVM_SET_VCPU_EVENTS, in fact it places it last.  This is because
KVM needs to know whether the processor is in SMM or not.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 tools/testing/selftests/kvm/Makefile               |   1 +
 .../selftests/kvm/include/x86_64/processor.h       |  27 ++++
 tools/testing/selftests/kvm/lib/x86_64/processor.c |  12 +-
 tools/testing/selftests/kvm/x86_64/smm_test.c      | 157 +++++++++++++++++++++
 4 files changed, 191 insertions(+), 6 deletions(-)
 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 2d2e10b219d5..f8588cca2bef 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -19,6 +19,7 @@ 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/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index b363c9611bd6..dc7fae9fa424 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -1101,12 +1101,6 @@ void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_x86_state *s
 	struct vcpu *vcpu = vcpu_find(vm, vcpuid);
 	int r;
 
-	if (state->nested.size) {
-		r = ioctl(vcpu->fd, KVM_SET_NESTED_STATE, &state->nested);
-		TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_NESTED_STATE, r: %i",
-			r);
-	}
-
 	r = ioctl(vcpu->fd, KVM_SET_XSAVE, &state->xsave);
         TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_XSAVE, r: %i",
                 r);
@@ -1138,4 +1132,10 @@ void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_x86_state *s
 	r = ioctl(vcpu->fd, KVM_SET_REGS, &state->regs);
         TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_REGS, r: %i",
                 r);
+
+	if (state->nested.size) {
+		r = ioctl(vcpu->fd, KVM_SET_NESTED_STATE, &state->nested);
+		TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_NESTED_STATE, r: %i",
+			r);
+	}
 }
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..436227c2ea39
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/smm_test.c
@@ -0,0 +1,157 @@
+// 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 65536
+#define SMRAM_MEMSLOT ((1 << 16) | 1)
+#define SMRAM_PAGES (SMRAM_SIZE / 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.
+ */
+uint8_t smi_handler[] = {
+	0xb0, SMRAM_STAGE,    /* mov $SMRAM_STAGE, %al */
+	0xe4, SYNC_PORT,      /* in $SYNC_PORT, %al */
+	0x0f, 0xaa,           /* rsm */
+};
+
+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);
+
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, SMRAM_GPA,
+				    SMRAM_MEMSLOT, SMRAM_PAGES, 0);
+	TEST_ASSERT(vm_phy_pages_alloc(vm, SMRAM_PAGES, SMRAM_GPA, SMRAM_MEMSLOT)
+		    == SMRAM_GPA, "could not allocate guest physical addresses?");
+
+	memset(addr_gpa2hva(vm, SMRAM_GPA), 0x0, SMRAM_SIZE);
+	memcpy(addr_gpa2hva(vm, SMRAM_GPA) + 0x8000, smi_handler,
+	       sizeof(smi_handler));
+
+	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);
+
+		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);
+}
-- 
1.8.3.1