On Thu, Feb 04, 2010 at 08:21:08PM +0100, Jan Kiszka wrote: > Jan Kiszka wrote: > > Marcelo Tosatti wrote: > >> With kvm-autotest the failure is not sporadic (and the above commit > >> applied): with KVM_SET_GUEST_DEBUG in arch_put_regs all migration > >> tests fail, without, all of them succeed. > >> > >> So env->kvm_guest_debug has been zeroed by cpu_x86_init, which means > >> the writeback via KVM_SET_GUEST_DEBUG does almost nothing. It does > >> get_rflags and set_rflags in the kernel. > > > > Hmm, it also copies debug regs around... BTW, where do we save/restore > > dr0..7 between kernel and user space? > > > > But that should not be a problem, both shadow as well as effective regs > > should be properly initialized, specifically for a newly created VCPU. > > Could you retry after pushing SET_GUEST_DEBUG at the end of > kvm_arch_put_registers? Maybe it is no good idea to run get/set_rflags > without having the sregs properly initialized. > > Jan Can't reproduce (with the original patch, KVM_SET_GUEST_DEBUG at beginning of arch_put_regs). Different test box though. Go figure. Anyway, as you mentioned, the workaround can be made cleaner through set_vcpu_events. -- 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
