On 06/12/16 19:56, Christoffer Dall wrote: > On Tue, Dec 06, 2016 at 11:25:42AM +0000, Marc Zyngier wrote: >> On 05/12/16 09:32, Christoffer Dall wrote: >>> When the arch timer code fails to initialize (for example because the >>> memory mapped timer doesn't work, which is currently seen with the AEM >>> model), then KVM just continues happily with a final result that KVM >>> eventually does a NULL pointer dereference of the uninitialized cycle >>> counter. >>> >>> Check directly for this in the init path and give the user a reasonable >>> error in this case. >>> >>> Cc: Shih-Wei Li <shihwei@xxxxxxxxxxxxxxx> >>> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> >>> --- >>> virt/kvm/arm/arch_timer.c | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c >>> index 27a1f63..5c12f53 100644 >>> --- a/virt/kvm/arm/arch_timer.c >>> +++ b/virt/kvm/arm/arch_timer.c >>> @@ -425,6 +425,11 @@ int kvm_timer_hyp_init(void) >>> info = arch_timer_get_kvm_info(); >>> timecounter = &info->timecounter; >>> >>> + if (!timecounter->cc) { >>> + kvm_err("arch_timer: uninitialized timecounter\n"); >> >> For consistency, I'll change the error message to say "kvm_arch_timer", >> just like the below case. >> > > No objections, only problem is that the patch you queued uses > kcm_arch_timer ;) Yeah, that's the new and upgraded version: Kernel Cryogenic Machine, it freezes time ;-). I'll fix that shortly, thanks for the heads up! M. -- Jazz is not dead. It just smells funny... -- 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