VNCR TLB invalidation occurs from MMU notifiers or TLBI instructions, and either can race against a vcpu not being onlined yet (no pseudo-TLB allocated). Similarly, the TLB might be invalid, and the invalidation should be skipped in this case. Both kvm_invalidate_vncr_ipa() and kvm_invalidate_vncr_va() are expected to perform the same checks, except that the latter doesn't check for the allocation and blindly dereferences the pointer. Solve this by introducing a new iterator built on top of the usual kvm_for_each_vcpu() that checks for both of the above conditions, and convert the two users to it. Reported-by: Hyunwoo Kim Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/aiUvSbrWndQeUPc8@v4bel Fixes: 4ffa72ad8f37 ("KVM: arm64: nv: Add S1 TLB invalidation primitive for VNCR_EL2") Cc: stable@vger.kernel.org --- arch/arm64/kvm/nested.c | 36 +++++++++++++++--------------------- 1 file changed, 15 insertions(+), 21 deletions(-) diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index f8d3f3a723282..690b8e8564166 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -908,9 +908,21 @@ static void invalidate_vncr(struct vncr_tlb *vt) clear_fixmap(vncr_fixmap(vt->cpu)); } +/* + * VNCR TLB invalidation occurs from MMU notifiers or TLBI instructions, and + * either can race against a vcpu not being onlined yet (no pseudo-TLB + * allocated). Similarly, the TLB might be invalid. Skip those, as they + * obviously don't participate in the invalidation at this stage. + */ +#define kvm_for_each_vncr_tlb(idx, vcpup, tlbp, kvm) \ + kvm_for_each_vcpu(idx, vcpup, kvm) \ + if (((tlbp) = vcpup->arch.vncr_tlb) && \ + (tlbp)->valid) + static void kvm_invalidate_vncr_ipa(struct kvm *kvm, u64 start, u64 end) { struct kvm_vcpu *vcpu; + struct vncr_tlb *vt; unsigned long i; lockdep_assert_held_write(&kvm->mmu_lock); @@ -918,24 +930,9 @@ static void kvm_invalidate_vncr_ipa(struct kvm *kvm, u64 start, u64 end) if (!kvm_has_feat(kvm, ID_AA64MMFR4_EL1, NV_frac, NV2_ONLY)) return; - kvm_for_each_vcpu(i, vcpu, kvm) { - struct vncr_tlb *vt = vcpu->arch.vncr_tlb; + kvm_for_each_vncr_tlb(i, vcpu, vt, kvm) { u64 ipa_start, ipa_end, ipa_size; - /* - * Careful here: We end-up here from an MMU notifier, - * and this can race against a vcpu not being onlined - * yet, without the pseudo-TLB being allocated. - * - * Skip those, as they obviously don't participate in - * the invalidation at this stage. - */ - if (!vt) - continue; - - if (!vt->valid) - continue; - ipa_size = ttl_to_size(pgshift_level_to_ttl(vt->wi.pgshift, vt->wr.level)); ipa_start = vt->wr.pa & ~(ipa_size - 1); @@ -965,17 +962,14 @@ static void invalidate_vncr_va(struct kvm *kvm, struct s1e2_tlbi_scope *scope) { struct kvm_vcpu *vcpu; + struct vncr_tlb *vt; unsigned long i; lockdep_assert_held_write(&kvm->mmu_lock); - kvm_for_each_vcpu(i, vcpu, kvm) { - struct vncr_tlb *vt = vcpu->arch.vncr_tlb; + kvm_for_each_vncr_tlb(i, vcpu, vt, kvm) { u64 va_start, va_end, va_size; - if (!vt->valid) - continue; - va_size = ttl_to_size(pgshift_level_to_ttl(vt->wi.pgshift, vt->wr.level)); va_start = vt->gva & ~(va_size - 1); -- 2.47.3