Il 04/09/2013 17:26, Arthur Chunqi Li ha scritto:
> Test cases for preemption timer in nested VMX. Two aspects are tested:
> 1. Save preemption timer on VMEXIT if relevant bit set in EXIT_CONTROL
> 2. Test a relevant bug of KVM. The bug will not save preemption timer
> value if exit L2->L0 for some reason and enter L0->L2. Thus preemption
> timer will never trigger if the value is large enough.
>
> Signed-off-by: Arthur Chunqi Li <yzt356@xxxxxxxxx>
> ---
> x86/vmx.h | 3 ++
> x86/vmx_tests.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 120 insertions(+)
Please rebase your other four patches on top of this one, since this one
is good to go!
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Paolo
> +void preemption_timer_init()
> +{
> + u32 ctrl_pin;
> +
> + ctrl_pin = vmcs_read(PIN_CONTROLS) | PIN_PREEMPT;
> + ctrl_pin &= ctrl_pin_rev.clr;
> + vmcs_write(PIN_CONTROLS, ctrl_pin);
> + preempt_val = 10000000;
> + vmcs_write(PREEMPT_TIMER_VALUE, preempt_val);
> + preempt_scale = rdmsr(MSR_IA32_VMX_MISC) & 0x1F;
> +}
> +
> +void preemption_timer_main()
> +{
> + tsc_val = rdtsc();
> + if (!(ctrl_pin_rev.clr & PIN_PREEMPT)) {
> + printf("\tPreemption timer is not supported\n");
> + return;
> + }
> + if (!(ctrl_exit_rev.clr & EXI_SAVE_PREEMPT))
> + printf("\tSave preemption value is not supported\n");
> + else {
> + set_stage(0);
> + vmcall();
> + if (get_stage() == 1)
> + vmcall();
> + }
> + while (1) {
> + if (((rdtsc() - tsc_val) >> preempt_scale)
> + > 10 * preempt_val) {
> + report("Preemption timer", 0);
> + break;
> + }
> + }
> +}
> +
> +int preemption_timer_exit_handler()
> +{
> + u64 guest_rip;
> + ulong reason;
> + u32 insn_len;
> + u32 ctrl_exit;
> +
> + guest_rip = vmcs_read(GUEST_RIP);
> + reason = vmcs_read(EXI_REASON) & 0xff;
> + insn_len = vmcs_read(EXI_INST_LEN);
> + switch (reason) {
> + case VMX_PREEMPT:
> + if (((rdtsc() - tsc_val) >> preempt_scale) < preempt_val)
> + report("Preemption timer", 0);
> + else
> + report("Preemption timer", 1);
> + return VMX_TEST_VMEXIT;
> + case VMX_VMCALL:
> + switch (get_stage()) {
> + case 0:
> + if (vmcs_read(PREEMPT_TIMER_VALUE) != preempt_val)
> + report("Save preemption value", 0);
> + else {
> + set_stage(get_stage() + 1);
> + ctrl_exit = (vmcs_read(EXI_CONTROLS) |
> + EXI_SAVE_PREEMPT) & ctrl_exit_rev.clr;
> + vmcs_write(EXI_CONTROLS, ctrl_exit);
> + }
> + break;
> + case 1:
> + if (vmcs_read(PREEMPT_TIMER_VALUE) >= preempt_val)
> + report("Save preemption value", 0);
> + else
> + report("Save preemption value", 1);
> + break;
> + default:
> + printf("Invalid stage.\n");
> + print_vmexit_info();
> + return VMX_TEST_VMEXIT;
> + }
> + 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
> basic_* just implement some basic functions */
> struct vmx_test vmx_tests[] = {
> @@ -83,5 +198,7 @@ struct vmx_test vmx_tests[] = {
> basic_syscall_handler, {0} },
> { "vmenter", basic_init, vmenter_main, vmenter_exit_handler,
> basic_syscall_handler, {0} },
> + { "preemption timer", preemption_timer_init, preemption_timer_main,
> + preemption_timer_exit_handler, basic_syscall_handler, {0} },
> { NULL, NULL, NULL, NULL, NULL, {0} },
> };
>
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