On Mon, 20 Feb 2023 12:37:55 -0600
Michael Roth <michael.roth@xxxxxxx> wrote:
> From: Vishal Annapurve <vannapurve@xxxxxxxxxx>
>
> Introduce HVA range operator so that other KVM subsystems
> can operate on HVA range.
>
> Signed-off-by: Vishal Annapurve <vannapurve@xxxxxxxxxx>
> [mdr: minor checkpatch alignment fixups]
> Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
> ---
> include/linux/kvm_host.h | 6 +++++
> virt/kvm/kvm_main.c | 48 ++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 54 insertions(+)
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 4d542060cd93..c615650ed256 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -1402,6 +1402,12 @@ void kvm_mmu_invalidate_begin(struct kvm *kvm);
> void kvm_mmu_invalidate_range_add(struct kvm *kvm, gfn_t start, gfn_t end);
> void kvm_mmu_invalidate_end(struct kvm *kvm);
>
> +typedef int (*kvm_hva_range_op_t)(struct kvm *kvm,
> + struct kvm_gfn_range *range, void *data);
> +
> +int kvm_vm_do_hva_range_op(struct kvm *kvm, unsigned long hva_start,
> + unsigned long hva_end, kvm_hva_range_op_t handler, void *data);
> +
> long kvm_arch_dev_ioctl(struct file *filp,
> unsigned int ioctl, unsigned long arg);
> long kvm_arch_vcpu_ioctl(struct file *filp,
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index f7e00593cc5d..4ccd655dd5af 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -642,6 +642,54 @@ static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
> return (int)ret;
> }
>
Below function seems a reduced duplicate of __kvm_handle_hva_range()
in virt/kvm/kvm_main.c. It would be nice to factor __kvm_handle_hva_range().
> +int kvm_vm_do_hva_range_op(struct kvm *kvm, unsigned long hva_start,
> + unsigned long hva_end, kvm_hva_range_op_t handler, void *data)
> +{
> + int ret = 0;
> + struct kvm_gfn_range gfn_range;
> + struct kvm_memory_slot *slot;
> + struct kvm_memslots *slots;
> + int i, idx;
> +
> + if (WARN_ON_ONCE(hva_end <= hva_start))
> + return -EINVAL;
> +
> + idx = srcu_read_lock(&kvm->srcu);
> +
> + for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
> + struct interval_tree_node *node;
> +
> + slots = __kvm_memslots(kvm, i);
> + kvm_for_each_memslot_in_hva_range(node, slots,
> + hva_start, hva_end - 1) {
> + unsigned long start, end;
> +
> + slot = container_of(node, struct kvm_memory_slot,
> + hva_node[slots->node_idx]);
> + start = max(hva_start, slot->userspace_addr);
> + end = min(hva_end, slot->userspace_addr +
> + (slot->npages << PAGE_SHIFT));
> +
> + /*
> + * {gfn(page) | page intersects with [hva_start, hva_end)} =
> + * {gfn_start, gfn_start+1, ..., gfn_end-1}.
> + */
> + gfn_range.start = hva_to_gfn_memslot(start, slot);
> + gfn_range.end = hva_to_gfn_memslot(end + PAGE_SIZE - 1, slot);
> + gfn_range.slot = slot;
> +
> + ret = handler(kvm, &gfn_range, data);
> + if (ret)
> + goto e_ret;
> + }
> + }
> +
> +e_ret:
> + srcu_read_unlock(&kvm->srcu, idx);
> +
> + return ret;
> +}
> +
> static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
> unsigned long start,
> unsigned long end,
