> +#define CLOBBERED_SLOT TEST_MEM_SLOT_BASE Upon self-review, this should have been hardcoded to 1 (to clobber the reserved ucal mmio).
> + ret = __vm_set_user_memory_region2(vm, CLOBBERED_SLOT, 0, > + vm->ucall_mmio_addr, slot_size, > slot_mem, 0, 0); > + TEST_ASSERT(ret == -1 && errno == EEXIST, > + "Expected the ucall GPA overlap to be rejected: ret=%d > errno=%d", > + ret, errno); This should have been errno == EINVAL check to catch writing to the exiting read-only slot. The earlier test accidentally passed because it used a different slot ID (=2, not reserved) and received EEXIST for overlapping the reserved ucall GPA. It therefore tested GPA overlap rejection, not the intended rejection of overwriting slot 1. I will fix it in v2
