diff options
Diffstat (limited to 'results/classifier/105/instruction/1574346')
| -rw-r--r-- | results/classifier/105/instruction/1574346 | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/results/classifier/105/instruction/1574346 b/results/classifier/105/instruction/1574346 new file mode 100644 index 000000000..410bb5bab --- /dev/null +++ b/results/classifier/105/instruction/1574346 @@ -0,0 +1,41 @@ +instruction: 0.779 +other: 0.750 +graphic: 0.731 +device: 0.728 +mistranslation: 0.635 +semantic: 0.551 +network: 0.544 +socket: 0.467 +vnc: 0.421 +boot: 0.390 +assembly: 0.341 +KVM: 0.339 + +TCG: mov to segment register is incorrectly emulated for AMD CPUs + +In TCG mode, the effect of: + +xorl %eax, %eax +movl %eax, %gs + +is to mark the GS segment unusable and set its base to zero. After doing this, reading MSR_GS_BASE will return zero and using a GS prefix in long mode will treat the GS base as zero. + +This is correct for Intel CPUs but is incorrect for AMD CPUs. On an AMD CPU, writing 0 to %gs using mov, pop, or (I think) lgs will leave the base unchanged. + +To make it easier to use TCG to validate behavior on different CPUs, please consider changing the TCG behavior to match actual CPU behavior when emulating an AMD CPU. + +The QEMU project is currently considering to move its bug tracking to +another system. For this we need to know which bugs are still valid +and which could be closed already. Thus we are setting older bugs to +"Incomplete" now. + +If you still think this bug report here is valid, then please switch +the state back to "New" within the next 60 days, otherwise this report +will be marked as "Expired". Or please mark it as "Fix Released" if +the problem has been solved with a newer version of QEMU already. + +Thank you and sorry for the inconvenience. + + +[Expired for QEMU because there has been no activity for 60 days.] + |