This checks that we properly expire the preemption timer also while the guest is in HLT state.
Signed-off-by: Jan Kiszka <[email protected]> --- x86/vmx_tests.c | 40 +++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-) diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c index 27ab032..8952077 100644 --- a/x86/vmx_tests.c +++ b/x86/vmx_tests.c @@ -126,13 +126,18 @@ void preemption_timer_main() if (get_stage() == 1) vmcall(); } - while (1) { + set_stage(1); + while (get_stage() == 1) { if (((rdtsc() - tsc_val) >> preempt_scale) > 10 * preempt_val) { set_stage(2); vmcall(); } } + tsc_val = rdtsc(); + asm volatile ("hlt"); + set_stage(4); + vmcall(); } int preemption_timer_exit_handler() @@ -147,33 +152,50 @@ int preemption_timer_exit_handler() 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); + switch (get_stage()) { + case 1: + case 2: + report("busy-wait for preemption timer", + ((rdtsc() - tsc_val) >> preempt_scale) >= + preempt_val); + set_stage(3); + vmcs_write(PREEMPT_TIMER_VALUE, preempt_val); + return VMX_TEST_RESUME; + case 3: + report("preemption timer during hlt", + ((rdtsc() - tsc_val) >> preempt_scale) >= + preempt_val); + break; + default: + printf("Invalid stage.\n"); + print_vmexit_info(); + break; + } break; case VMX_VMCALL: + vmcs_write(GUEST_RIP, guest_rip + insn_len); switch (get_stage()) { case 0: if (vmcs_read(PREEMPT_TIMER_VALUE) != preempt_val) report("Save preemption value", 0); else { - set_stage(get_stage() + 1); + set_stage(1); ctrl_exit = (vmcs_read(EXI_CONTROLS) | EXI_SAVE_PREEMPT) & ctrl_exit_rev.clr; vmcs_write(EXI_CONTROLS, ctrl_exit); } - vmcs_write(GUEST_RIP, guest_rip + insn_len); return VMX_TEST_RESUME; case 1: if (vmcs_read(PREEMPT_TIMER_VALUE) >= preempt_val) report("Save preemption value", 0); else report("Save preemption value", 1); - vmcs_write(GUEST_RIP, guest_rip + insn_len); return VMX_TEST_RESUME; case 2: - report("Preemption timer", 0); + report("busy-wait for preemption timer", 0); + return VMX_TEST_RESUME; + case 3: + report("preemption timer during hlt", 0); break; default: printf("Invalid stage.\n"); -- 1.8.1.1.298.ge7eed54 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
