This checks some usage cases of VMX MSR load/store feature:
1) VM-entry MSR-load area is correctly filled
2) VM-exit MSR-store area is correctly filled
3) VM-exit MSR-load area is correctly filled
4) Attempt to load MSR_FS_BASE on VM entry (must generate
VM-entry failure due to MSR loading)
Signed-off-by: Eugene Korenevsky <ekorenevsky@xxxxxxxxx>
---
x86/vmx_tests.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 76 insertions(+)
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index 184fafc..913904a 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -1525,6 +1525,80 @@ static int dbgctls_exit_handler(void)
return VMX_TEST_VMEXIT;
}
+struct vmx_msr_entry {
+ u32 index;
+ u32 reserved;
+ u64 value;
+} __attribute__((packed));
+
+#define MSR_MAGIC 0x31415926
+struct vmx_msr_entry *exit_msr_store, *entry_msr_load, *exit_msr_load;
+
+static int msr_switch_init(struct vmcs *vmcs)
+{
+ msr_bmp_init();
+ exit_msr_store = alloc_page();
+ exit_msr_load = alloc_page();
+ entry_msr_load = alloc_page();
+ memset(exit_msr_store, 0, PAGE_SIZE);
+ memset(exit_msr_load, 0, PAGE_SIZE);
+ memset(entry_msr_load, 0, PAGE_SIZE);
+ entry_msr_load[0].index = MSR_KERNEL_GS_BASE;
+ entry_msr_load[0].value = MSR_MAGIC;
+
+ vmx_set_test_stage(1);
+ vmcs_write(ENT_MSR_LD_CNT, 1);
+ vmcs_write(ENTER_MSR_LD_ADDR, (u64)entry_msr_load);
+ vmcs_write(EXI_MSR_ST_CNT, 1);
+ vmcs_write(EXIT_MSR_ST_ADDR, (u64)exit_msr_store);
+ vmcs_write(EXI_MSR_LD_CNT, 1);
+ vmcs_write(EXIT_MSR_LD_ADDR, (u64)exit_msr_load);
+ return VMX_TEST_START;
+}
+
+static void msr_switch_main()
+{
+ if (vmx_get_test_stage() == 1) {
+ report("VM entry MSR load",
+ rdmsr(MSR_KERNEL_GS_BASE) == MSR_MAGIC);
+ vmx_set_test_stage(2);
+ wrmsr(MSR_KERNEL_GS_BASE, MSR_MAGIC + 1);
+ exit_msr_store[0].index = MSR_KERNEL_GS_BASE;
+ exit_msr_load[0].index = MSR_KERNEL_GS_BASE;
+ exit_msr_load[0].value = MSR_MAGIC + 2;
+ }
+ vmcall();
+}
+
+static int msr_switch_exit_handler()
+{
+ ulong reason;
+
+ reason = vmcs_read(EXI_REASON);
+ switch (reason) {
+ case 0x80000000 | VMX_FAIL_MSR:
+ if (vmx_get_test_stage() == 3) {
+ report("VM entry MSR load: try to load FS_BASE",
+ vmcs_read(EXI_QUALIFICATION) == 1);
+ return VMX_TEST_VMEXIT;
+ }
+ break;
+ case VMX_VMCALL:
+ if (vmx_get_test_stage() == 2) {
+ report("VM exit MSR store",
+ exit_msr_store[0].value == MSR_MAGIC + 1);
+ report("VM exit MSR load",
+ rdmsr(MSR_KERNEL_GS_BASE) == MSR_MAGIC + 2);
+ vmx_set_test_stage(3);
+ entry_msr_load[0].index = MSR_FS_BASE;
+ return VMX_TEST_RESUME;
+ }
+ }
+ printf("ERROR %s: unexpected stage=%u or reason=%lu\n",
+ __func__, vmx_get_test_stage(), reason);
+ return VMX_TEST_EXIT;
+}
+
/* name/init/guest_main/exit_handler/syscall_handler/guest_regs */
struct vmx_test vmx_tests[] = {
{ "null", NULL, basic_guest_main, basic_exit_handler, NULL, {0} },
@@ -1546,5 +1620,7 @@ struct vmx_test vmx_tests[] = {
interrupt_exit_handler, NULL, {0} },
{ "debug controls", dbgctls_init, dbgctls_main, dbgctls_exit_handler,
NULL, {0} },
+ { "MSR switch", msr_switch_init, msr_switch_main,
+ msr_switch_exit_handler, NULL, {0} },
{ NULL, NULL, NULL, NULL, NULL, {0} },
};
--
2.0.4
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