On 08/21/2012 01:39 PM, Marc Zyngier wrote: > 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. Did you maybe compile them with different config options? Like preemption? :) Alex _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
