On Tue Aug 15, 2023 at 8:18 PM EEST, wrote:
> From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
>
> kvm_mmu_invalidate_end() updates struct kvm::mmu_invalidate_in_progress
> and it's protected by kvm::mmu_lock. call kvm_mmu_invalidate_end() before
> unlocking it. Not after the unlock.
>
> Fixes: 8e9009ca6d14 ("KVM: Introduce per-page memory attributes")
> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> ---
> virt/kvm/kvm_main.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 8bfeb615fc4d..49380cd62367 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -535,6 +535,7 @@ struct kvm_mmu_notifier_range {
> } arg;
> gfn_handler_t handler;
> on_lock_fn_t on_lock;
> + on_unlock_fn_t before_unlock;
> on_unlock_fn_t on_unlock;
> bool flush_on_ret;
> bool may_block;
> @@ -629,6 +630,8 @@ static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
> kvm_flush_remote_tlbs(kvm);
>
> if (locked) {
> + if (!IS_KVM_NULL_FN(range->before_unlock))
> + range->before_unlock(kvm);
> KVM_MMU_UNLOCK(kvm);
> if (!IS_KVM_NULL_FN(range->on_unlock))
> range->on_unlock(kvm);
> @@ -653,6 +656,7 @@ static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
> .arg.pte = pte,
> .handler = handler,
> .on_lock = (void *)kvm_null_fn,
> + .before_unlock = (void *)kvm_null_fn,
> .on_unlock = (void *)kvm_null_fn,
> .flush_on_ret = true,
> .may_block = false,
> @@ -672,6 +676,7 @@ static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn
> .end = end,
> .handler = handler,
> .on_lock = (void *)kvm_null_fn,
> + .before_unlock = (void *)kvm_null_fn,
> .on_unlock = (void *)kvm_null_fn,
> .flush_on_ret = false,
> .may_block = false,
> @@ -776,6 +781,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
> .end = range->end,
> .handler = kvm_mmu_unmap_gfn_range,
> .on_lock = kvm_mmu_invalidate_begin,
> + .before_unlock = (void *)kvm_null_fn,
> .on_unlock = kvm_arch_guest_memory_reclaimed,
> .flush_on_ret = true,
> .may_block = mmu_notifier_range_blockable(range),
> @@ -815,6 +821,8 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
>
> void kvm_mmu_invalidate_end(struct kvm *kvm)
> {
> + lockdep_assert_held_write(&kvm->mmu_lock);
> +
> /*
> * This sequence increase will notify the kvm page fault that
> * the page that is going to be mapped in the spte could have
> @@ -846,6 +854,7 @@ static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
> .end = range->end,
> .handler = (void *)kvm_null_fn,
> .on_lock = kvm_mmu_invalidate_end,
> + .before_unlock = (void *)kvm_null_fn,
> .on_unlock = (void *)kvm_null_fn,
> .flush_on_ret = false,
> .may_block = mmu_notifier_range_blockable(range),
> @@ -2433,6 +2442,8 @@ static __always_inline void kvm_handle_gfn_range(struct kvm *kvm,
> kvm_flush_remote_tlbs(kvm);
>
> if (locked) {
> + if (!IS_KVM_NULL_FN(range->before_unlock))
> + range->before_unlock(kvm);
> KVM_MMU_UNLOCK(kvm);
> if (!IS_KVM_NULL_FN(range->on_unlock))
> range->on_unlock(kvm);
> @@ -2447,6 +2458,7 @@ static int kvm_vm_set_mem_attributes(struct kvm *kvm, unsigned long attributes,
> .end = end,
> .handler = kvm_mmu_unmap_gfn_range,
> .on_lock = kvm_mmu_invalidate_begin,
> + .before_unlock = (void *)kvm_null_fn,
> .on_unlock = (void *)kvm_null_fn,
> .flush_on_ret = true,
> .may_block = true,
> @@ -2457,7 +2469,8 @@ static int kvm_vm_set_mem_attributes(struct kvm *kvm, unsigned long attributes,
> .arg.attributes = attributes,
> .handler = kvm_arch_post_set_memory_attributes,
> .on_lock = (void *)kvm_null_fn,
> - .on_unlock = kvm_mmu_invalidate_end,
> + .before_unlock = kvm_mmu_invalidate_end,
> + .on_unlock = (void *)kvm_null_fn,
> .may_block = true,
> };
> unsigned long i;
> --
> 2.25.1
Acked-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
BR, Jarkko
