On 20/08/12 21:45, Christoffer Dall wrote: > On Mon, Aug 20, 2012 at 1:22 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >> Guys, >> >> I'm seeing weird regressions on v11 when running Thumb2 code: >> >> [ 315.637769] cyclictest (3319): undefined instruction: pc=0000a2f4 >> [ 315.637791] Code: 4640 4649 f002 fbc4 (ed95) 7b06 >> [ 316.216214] cyclictest (3324): undefined instruction: pc=0000a2f4 >> [ 316.217515] Code: 4640 4649 f002 fbc4 (ed95) 7b06 >> [ 325.854063] cyclictest (3444): undefined instruction: pc=0000a2f4 >> [ 325.854076] Code: 4640 4649 f002 fbc4 (ed95) 7b06 >> >> My previous work branch was quite solid (v10 based). Do we have a clear >> idea of what's changed in the exception handling path? Or should I >> consider doing the diff dance? >> >> I have the ugly feeling that we're adjusting the PC in a creative way. >> > > if that's the case, it's probably the kvm_skip_instr() thingy. Which > code are you running? simply a Thumb guest kernel or something in user > space? If the latter, can you share? This is a Thumb2 guest + userspace guest. The instruction is always the same VFP instruction, so it actually looks VFP related, not PC adjusting as I initially thought. Doing stuff on the host seems to easily trigger the problem on the gust. But there's very little difference between my two trees (at least VFP wise), hence my growing perplexity... I'll continue investigating. M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
