On 31/07/19 14:43, Christian Borntraeger wrote: >>>>>> if (has_xsave) { >>>>>> env->xsave_buf = qemu_memalign(4096, sizeof(struct kvm_xsave)); >>>>>> + memset(env->xsave_buf, 0, sizeof(struct kvm_xsave)); > This is memsetting 4k? > Yet another variant would be to use the RUNNING_ON_VALGRIND macro from > valgrind/valgrind.h to only memset for valgrind. But just using MAKE_MEM_DEFINED > from memcheck.h is simpler. > Yes, it's 4k but only at initialization time and I actually prefer not to have potentially uninitialized host data in there. Paolo