On Thu, May 30, 2024 at 11:07 PM Rick Edgecombe
<rick.p.edgecombe@xxxxxxxxx> wrote:
> + /* Unmmap the old attribute page. */
Unmap
> + if (range->arg.attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE)
> + range->process = KVM_PROCESS_SHARED;
> + else
> + range->process = KVM_PROCESS_PRIVATE;
> +
> return kvm_unmap_gfn_range(kvm, range);
> }
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index c3c922bf077f..f92c8b605b03 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -260,11 +260,19 @@ union kvm_mmu_notifier_arg {
> unsigned long attributes;
> };
>
> +enum kvm_process {
> + BUGGY_KVM_INVALIDATION = 0,
> + KVM_PROCESS_SHARED = BIT(0),
> + KVM_PROCESS_PRIVATE = BIT(1),
> + KVM_PROCESS_PRIVATE_AND_SHARED = KVM_PROCESS_SHARED | KVM_PROCESS_PRIVATE,
> +};
Only KVM_PROCESS_SHARED and KVM_PROCESS_PRIVATE are needed.
> + /*
> + * If/when KVM supports more attributes beyond private .vs shared, this
> + * _could_ set exclude_{private,shared} appropriately if the entire target
this could mask away KVM_PROCESS_{SHARED,PRIVATE} if the entire target...
Paolo
> + * range already has the desired private vs. shared state (it's unclear
> + * if that is a net win). For now, KVM reaches this point if and only
> + * if the private flag is being toggled, i.e. all mappings are in play.
> + */
> +
> for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
> slots = __kvm_memslots(kvm, i);
>
> @@ -2506,6 +2519,7 @@ static int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end,
> struct kvm_mmu_notifier_range pre_set_range = {
> .start = start,
> .end = end,
> + .arg.attributes = attributes,
> .handler = kvm_pre_set_memory_attributes,
> .on_lock = kvm_mmu_invalidate_begin,
> .flush_on_ret = true,
> --
> 2.34.1
>
