On 30/11/2017 19:05, Radim Krčmář wrote:
> Does roughly what kvm_mmu_notifier_invalidate_page did before.
>
> I am not certain why this would be needed. It might mean that we have
> another bug with start/end or just that I missed something.
I don't think this is needed, because we don't have shared page tables.
My understanding is that without shared page tables, you can assume that
all page modifications go through invalidate_range_start/end. With
shared page tables, there are additional TLB flushes to take care of,
which require invalidate_range.
Thanks,
Paolo
> Please try just [1/2] first and apply this one only if [1/2] still bugs,
> thanks!
> ---
> virt/kvm/kvm_main.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index b7f4689e373f..0825ea624f16 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -342,6 +342,29 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
> srcu_read_unlock(&kvm->srcu, idx);
> }
>
> +static void kvm_mmu_notifier_invalidate_range(struct mmu_notifier *mn,
> + struct mm_struct *mm,
> + unsigned long start,
> + unsigned long end)
> +{
> + struct kvm *kvm = mmu_notifier_to_kvm(mn);
> + int need_tlb_flush = 0, idx;
> +
> + idx = srcu_read_lock(&kvm->srcu);
> + spin_lock(&kvm->mmu_lock);
> + kvm->mmu_notifier_seq++;
> + need_tlb_flush = kvm_unmap_hva_range(kvm, start, end);
> + need_tlb_flush |= kvm->tlbs_dirty;
> + if (need_tlb_flush)
> + kvm_flush_remote_tlbs(kvm);
> +
> + spin_unlock(&kvm->mmu_lock);
> +
> + kvm_arch_mmu_notifier_invalidate_range(kvm, start, end);
> +
> + srcu_read_unlock(&kvm->srcu, idx);
> +}
> +
> static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
> struct mm_struct *mm,
> unsigned long start,
> @@ -476,6 +499,7 @@ static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
> }
>
> static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
> + .invalidate_range = kvm_mmu_notifier_invalidate_range,
> .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
> .invalidate_range_end = kvm_mmu_notifier_invalidate_range_end,
> .clear_flush_young = kvm_mmu_notifier_clear_flush_young,
>
