Some of the ARMv7 & ARMv8 load/store instructions might trigger a data abort exception with no valid ISS info to be decoded. The lack of decode info makes it at least tricky to emulate the instruction which is one of the (many) reasons why KVM will not even try to do so. So far, if a guest made an attempt to access memory outside the memory slot, KVM reported vague ENOSYS. As a result QEMU exited with no useful information being provided or even a clue on what has just happened. ARM KVM introduced support for notifying guest of an attempt to execute an instruction that resulted in dabt with no valid ISS decoding info. This still leaves QEMU to handle the case, but at least now, it can enable further debugging of the encountered issue by being more verbose in a (hopefully) useful way. v2: - Improving/re-phrasing messaging - Dropping messing around with forced sync (@see [PATCH v2 1/2]) and PC alignment Beata Michalska (2): target/arm: kvm: Inject events at the last stage of sync target/arm: kvm: Handle DABT with no valid ISS target/arm/cpu.h | 2 ++ target/arm/kvm.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++ target/arm/kvm32.c | 23 +++++++------ target/arm/kvm64.c | 23 +++++++------ target/arm/kvm_arm.h | 19 +++++++++++ 5 files changed, 143 insertions(+), 20 deletions(-) -- 2.7.4 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
