On Sat, Feb 11, 2012 at 14:00, Jan Kiszka <jan.kiszka@xxxxxx> wrote: > On 2012-02-11 14:54, Blue Swirl wrote: >> On Sat, Feb 11, 2012 at 12:43, Jan Kiszka <jan.kiszka@xxxxxx> wrote: >>> On 2012-02-11 12:49, Andreas Färber wrote: >>>> Am 11.02.2012 12:25, schrieb Blue Swirl: >>>>> I think using cpu_single_env is an indication of a problem, like poor >>>>> code, layering violation or poor API (vmport). What is your use case? >>>> >>>> I couldn't spot any in this series. Jan, note that any new use of env or >>>> cpu_single_env will need to be redone when we convert to QOM CPU. >>> >>> cpu_single_env should have nothing to do with QOM. >>> >>> The ABIs of vmport and the KVM VAPI require a reference to the calling >>> VCPU, and that's why you find tons of them in patch 5. >> >> Yes, this seems to be another case of a badly designed ABI. I guess >> there is no way to change that anymore, just like vmport? > > Believe me, I grumbled over it more than once while porting it from > qemu-kvm. The point is that some (Windows) VMs out there are running > already with this option ROM loaded and working this unfortunate ABI. Maybe in time those could be deprecated and a ROM using a sane ABI introduced instead. After some grace time the old ABI could be finally removed. >> >> Some of the cpu_single_env accesses in patch 5 could be avoided when >> APIC is moved closer to CPU. VAPIC should be also close to APIC so it >> should be able to access the CPU directly. In some other cases the >> current state could be passed around instead once it is known. > > Some callbacks are I/O-port originated, ie. not associated with the > per-CPU MMIO area or some MSR. So we would have to pass down the causing > CPU to every I/O handler - not sure if that is desired... I meant things like vapic_enable_tpr_reporting(), current CPUState could be passed via vapic_prepare() easily. > Jan > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
