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 <[email protected]>
> ---
>  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 <[email protected]>

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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