diff options
Diffstat (limited to 'results/classifier/zero-shot/108/other/2007')
| -rw-r--r-- | results/classifier/zero-shot/108/other/2007 | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/results/classifier/zero-shot/108/other/2007 b/results/classifier/zero-shot/108/other/2007 new file mode 100644 index 00000000..46980196 --- /dev/null +++ b/results/classifier/zero-shot/108/other/2007 @@ -0,0 +1,44 @@ +semantic: 0.833 +performance: 0.828 +device: 0.796 +graphic: 0.731 +other: 0.657 +debug: 0.627 +network: 0.617 +vnc: 0.565 +permissions: 0.528 +socket: 0.476 +PID: 0.469 +KVM: 0.441 +boot: 0.428 +files: 0.164 + +Unable to update APIC_TPR when x2APIC is enabled and -global kvm-pit.lost_tick_policy=discard parameter provided +Description of problem: +I am developing a custom OS and I wanted to implement x2APIC support. I was able to enable x2APIC, read and write some registers, like APIC_VER and APIC_SIVR. Everything looks good, except that I cannot update APIC_TPR register. Reading it always returns 0. The code I wrote works properly on bare metal. Below some observations: + +Scenario 1: +1. Enable x2APIC +2. Write to CR8 - success +3. Read from CR8 - gives correct value +4. Read from APIC_TPR - gives correct value + +Scenario 2: +1. Enable x2APIC +2. Read from APIC_TPR - gives 0 +3. Write to APIC_TPR +4. Read from APIC_TPR - gives 0 again + +Scenario 3: +1. Initialize APIC (LAPIC or xAPIC) +2. Write to APIC_TPR +3. Read from APIC_TPR - gives correct value +4. Switch to x2APIC +5. Read from APIC_TPR - gives correct value stored in pt. 2 +6. Write to APIC_TPR +7. Read from APIC_TPR - gives values stored in pt.2, not in point 6! + +Looks like APIC_TPR is stuck at value stored there before switching to x2APIC and it cannot be updated with MSR. Only update CR8 works. +I have checked parameters I passed to qemu. After removing `-global kvm-pit.lost_tick_policy=discard` problem is gone and APIC_TPR is updated correctly. +Additional information: +Please let me know if you need additional information. |