This particularly checks the case when debug controls are not to be
loaded/saved on host-guest transitions.
We have to fake results related to IA32_DEBUGCTL as support for this MSR
is missing KVM. The test already contains all bits required once KVM
adds support.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
x86/vmx.h | 2 +
x86/vmx_tests.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 114 insertions(+)
diff --git a/x86/vmx.h b/x86/vmx.h
index 87457b1..022f1df 100644
--- a/x86/vmx.h
+++ b/x86/vmx.h
@@ -305,6 +305,7 @@ enum Reason {
#define X86_EFLAGS_ZF 0x00000040 /* Zero Flag */
enum Ctrl_exi {
+ EXI_SAVE_DBGCTLS = 1UL << 2,
EXI_HOST_64 = 1UL << 9,
EXI_LOAD_PERF = 1UL << 12,
EXI_INTA = 1UL << 15,
@@ -316,6 +317,7 @@ enum Ctrl_exi {
};
enum Ctrl_ent {
+ ENT_LOAD_DBGCTLS = 1UL << 2,
ENT_GUEST_64 = 1UL << 9,
ENT_LOAD_PAT = 1UL << 14,
ENT_LOAD_EFER = 1UL << 15,
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index f02de3d..a97b6d6 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -1398,6 +1398,116 @@ static int interrupt_exit_handler(void)
return VMX_TEST_VMEXIT;
}
+static int dbgctls_init(struct vmcs *vmcs)
+{
+ u64 dr7 = 0x402;
+ u64 zero = 0;
+
+ msr_bmp_init();
+ asm volatile(
+ "mov %0,%%dr0\n\t"
+ "mov %0,%%dr1\n\t"
+ "mov %0,%%dr2\n\t"
+ "mov %1,%%dr7\n\t"
+ : : "r" (zero), "r" (dr7));
+ wrmsr(MSR_IA32_DEBUGCTLMSR, 0x1);
+ vmcs_write(GUEST_DR7, 0x404);
+ vmcs_write(GUEST_DEBUGCTL, 0x2);
+
+ vmcs_write(ENT_CONTROLS, vmcs_read(ENT_CONTROLS) | ENT_LOAD_DBGCTLS);
+ vmcs_write(EXI_CONTROLS, vmcs_read(EXI_CONTROLS) | EXI_SAVE_DBGCTLS);
+
+ return VMX_TEST_START;
+}
+
+static void dbgctls_main(void)
+{
+ u64 dr7, debugctl;
+
+ asm volatile("mov %%dr7,%0" : "=r" (dr7));
+ debugctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
+ /* Commented out: KVM does not support DEBUGCTL so far */
+ report("Load debug controls", dr7 == 0x404 /* && debugctl == 0x2 */);
+
+ dr7 = 0x408;
+ asm volatile("mov %0,%%dr7" : : "r" (dr7));
+ wrmsr(MSR_IA32_DEBUGCTLMSR, 0x3);
+
+ vmx_set_test_stage(0);
+ vmcall();
+ report("Save debug controls", vmx_get_test_stage() == 1);
+
+ if (ctrl_enter_rev.set & ENT_LOAD_DBGCTLS ||
+ ctrl_exit_rev.set & EXI_SAVE_DBGCTLS) {
+ printf("\tDebug controls are always loaded/saved\n");
+ return;
+ }
+ vmx_set_test_stage(2);
+ vmcall();
+
+ asm volatile("mov %%dr7,%0" : "=r" (dr7));
+ debugctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
+ /* Commented out: KVM does not support DEBUGCTL so far */
+ report("Guest=host debug controls", dr7 == 0x402 /* && debugctl == 0x1 */);
+
+ dr7 = 0x408;
+ asm volatile("mov %0,%%dr7" : : "r" (dr7));
+ wrmsr(MSR_IA32_DEBUGCTLMSR, 0x3);
+
+ vmx_set_test_stage(3);
+ vmcall();
+ report("Don't save debug controls", vmx_get_test_stage() == 4);
+}
+
+static int dbgctls_exit_handler(void)
+{
+ unsigned int reason = vmcs_read(EXI_REASON) & 0xff;
+ u32 insn_len = vmcs_read(EXI_INST_LEN);
+ u64 guest_rip = vmcs_read(GUEST_RIP);
+ u64 dr7, debugctl;
+
+ asm volatile("mov %%dr7,%0" : "=r" (dr7));
+ debugctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
+
+ switch (reason) {
+ case VMX_VMCALL:
+ switch (vmx_get_test_stage()) {
+ case 0:
+ if (dr7 == 0x400 && debugctl == 0 &&
+ vmcs_read(GUEST_DR7) == 0x408 /* &&
+ Commented out: KVM does not support DEBUGCTL so far
+ vmcs_read(GUEST_DEBUGCTL) == 0x3 */)
+ vmx_inc_test_stage();
+ break;
+ case 2:
+ dr7 = 0x402;
+ asm volatile("mov %0,%%dr7" : : "r" (dr7));
+ wrmsr(MSR_IA32_DEBUGCTLMSR, 0x1);
+ vmcs_write(GUEST_DR7, 0x404);
+ vmcs_write(GUEST_DEBUGCTL, 0x2);
+
+ vmcs_write(ENT_CONTROLS,
+ vmcs_read(ENT_CONTROLS) & ~ENT_LOAD_DBGCTLS);
+ vmcs_write(EXI_CONTROLS,
+ vmcs_read(EXI_CONTROLS) & ~EXI_SAVE_DBGCTLS);
+ break;
+ case 3:
+ if (dr7 == 0x400 && debugctl == 0 &&
+ vmcs_read(GUEST_DR7) == 0x404 /* &&
+ Commented out: KVM does not support DEBUGCTL so far
+ vmcs_read(GUEST_DEBUGCTL) == 0x2 */)
+ vmx_inc_test_stage();
+ break;
+ }
+ vmcs_write(GUEST_RIP, guest_rip + insn_len);
+ return VMX_TEST_RESUME;
+ default:
+ printf("Unknown exit reason, %d\n", reason);
+ print_vmexit_info();
+ }
+ return VMX_TEST_VMEXIT;
+}
+
/* 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} },
@@ -1417,5 +1527,7 @@ struct vmx_test vmx_tests[] = {
{ "EPT framework", ept_init, ept_main, ept_exit_handler, NULL, {0} },
{ "interrupt", interrupt_init, interrupt_main,
interrupt_exit_handler, NULL, {0} },
+ { "debug controls", dbgctls_init, dbgctls_main, dbgctls_exit_handler,
+ NULL, {0} },
{ NULL, NULL, NULL, NULL, NULL, {0} },
};
--
1.8.1.1.298.ge7eed54
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