Il 23/10/2013 16:21, Jan Kiszka ha scritto: > If we both print from L2 and, on timer expiry, from L1, we risk a > deadlock in L1 on the printf lock that is held by L2 then. Avoid this > by only printing from L1. > > Furthermore, if the timer fails to fire in time, disable it before > continuing to avoid that it fire later on in different contexts. > > Signed-off-by: Jan Kiszka <[email protected]> > --- > x86/vmx_tests.c | 26 ++++++++++++++++---------- > 1 file changed, 16 insertions(+), 10 deletions(-) > > diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c > index 8d47bcd..7893a6c 100644 > --- a/x86/vmx_tests.c > +++ b/x86/vmx_tests.c > @@ -128,6 +128,9 @@ void preemption_timer_init() > preempt_val = 10000000; > vmcs_write(PREEMPT_TIMER_VALUE, preempt_val); > preempt_scale = rdmsr(MSR_IA32_VMX_MISC) & 0x1F; > + > + if (!(ctrl_exit_rev.clr & EXI_SAVE_PREEMPT)) > + printf("\tSave preemption value is not supported\n"); > } > > void preemption_timer_main() > @@ -137,9 +140,7 @@ void preemption_timer_main() > 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 { > + if (ctrl_exit_rev.clr & EXI_SAVE_PREEMPT) { > set_stage(0); > vmcall(); > if (get_stage() == 1) > @@ -148,8 +149,8 @@ void preemption_timer_main() > while (1) { > if (((rdtsc() - tsc_val) >> preempt_scale) > > 10 * preempt_val) { > - report("Preemption timer", 0); > - break; > + set_stage(2); > + vmcall(); > } > } > } > @@ -170,7 +171,7 @@ int preemption_timer_exit_handler() > report("Preemption timer", 0); > else > report("Preemption timer", 1); > - return VMX_TEST_VMEXIT; > + break; > case VMX_VMCALL: > switch (get_stage()) { > case 0: > @@ -182,24 +183,29 @@ int preemption_timer_exit_handler() > EXI_SAVE_PREEMPT) & ctrl_exit_rev.clr; > vmcs_write(EXI_CONTROLS, ctrl_exit); > } > - break; > + 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); > break; > default: > printf("Invalid stage.\n"); > print_vmexit_info(); > - return VMX_TEST_VMEXIT; > + break; > } > - vmcs_write(GUEST_RIP, guest_rip + insn_len); > - return VMX_TEST_RESUME; > + break; > default: > printf("Unknown exit reason, %d\n", reason); > print_vmexit_info(); > } > + vmcs_write(PIN_CONTROLS, vmcs_read(PIN_CONTROLS) & ~PIN_PREEMPT); > return VMX_TEST_VMEXIT; > } > >
Applied to kvm-unit-tests.git vmx. Paolo -- 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
