The same error happens on linux-2.6.21.4:
I am using the same config as on 2.6.20 which worked well with kvm-28...
#
Output when compiling:
WARNING: "sigprocmask" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "kmem_cache_destroy" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "sysdev_unregister" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "mem_map" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "vmalloc" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "kill_anon_super" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "current_kernel_time" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "malloc_sizes" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "get_sb_pseudo" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "sysdev_class_register" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "mutex_unlock" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "vfree" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "igrab" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "mutex_trylock" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "cond_resched" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "__alloc_pages" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "misc_register" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "get_unused_fd" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "__mutex_init" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "printk" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "__PAGE_KERNEL" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "memcmp" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "vmap" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "copy_to_user" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "mutex_lock" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "sysdev_class_unregister" [/root/kvm/kvm-29/kernel/kvm.ko]
undefined!
WARNING: "fput" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "contig_page_data" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "unregister_reboot_notifier" [/root/kvm/kvm-29/kernel/kvm.ko]
undefined!
WARNING: "kern_mount" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "sysdev_register" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "__free_pages" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "mntput_no_expire" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "register_reboot_notifier" [/root/kvm/kvm-29/kernel/kvm.ko]
undefined!
WARNING: "d_alloc" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "put_unused_fd" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "kmem_cache_create" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "register_filesystem" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "free_pages" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "kmem_cache_zalloc" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "iput" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "kfree" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "vunmap" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "memcpy" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "fd_install" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "unregister_filesystem" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "new_inode" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "get_empty_filp" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "copy_from_user" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "simple_attr_open" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "misc_deregister" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "d_instantiate" [/root/kvm/kvm-29/kernel/kvm.ko] undefined!
WARNING: "kvm_resched" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "kvm_mmu_load" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "mem_map" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "save_msrs" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "kvm_set_msr_common" [/root/kvm/kvm-29/kernel/kvm-intel.ko]
undefined!
WARNING: "malloc_sizes" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "kvm_emulate_cpuid" [/root/kvm/kvm-29/kernel/kvm-intel.ko]
undefined!
WARNING: "kvm_read_guest" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "kvm_setup_pio" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "set_cr8" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "set_cr0" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "__alloc_pages" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "kvm_init_arch" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "printk" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "prof_on" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "kvm_hypercall" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "lmsw" [/root/kvm/kvm-29/kernel/kvm-intel.ko] undefined!
WARNING: "set_cr4"