Commit caa63620f9e3 ("KVM: Allow architectures to disallow pre-fault") requires every architecture that selects KVM_GENERIC_PRE_FAULT_MEMORY to implement kvm_arch_pre_fault_allowed(), and there is no generic default. Commit e8b32e377951 ("KVM: riscv: Implement KVM_PRE_FAULT_MEMORY") was written before that hook existed, so it selects the option without implementing the hook. With both commits in the same tree, riscv builds with KVM enabled fail to link: ld.lld: error: undefined symbol: kvm_arch_pre_fault_allowed >>> referenced by kvm_main.c >>> virt/kvm/kvm_main.o:(kvm_vcpu_pre_fault_memory) in archive vmlinux.a The riscv implementation does not refuse pre-faulting in any state, so return 0 to keep its current behaviour. Fixes: e8b32e377951 ("KVM: riscv: Implement KVM_PRE_FAULT_MEMORY") Signed-off-by: Sasha Levin --- Paolo, this is needed when kvm-riscv-7.4-1 is merged into kvm/next. Feel free to squash it into the merge instead. Mark, next-20261022 already fails to link, so linux-next needs this on top of the kvm-riscv merge. Build-tested with a riscv tinyconfig plus KVM=y on next-20261022 and on kvm/next with kvm-riscv-7.4-1 merged. Not runtime tested. arch/riscv/kvm/mmu.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index e8673cfa69668..738d9ee1eac9d 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -754,6 +754,11 @@ int kvm_riscv_mmu_map(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, return ret; } +int kvm_arch_pre_fault_allowed(struct kvm_vcpu *vcpu) +{ + return 0; +} + long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, struct kvm_pre_fault_memory *range) { -- 2.53.0