On Saturday, March 11, 2023 8:23 AM, Sean Christopherson wrote:
> Extract the memslot-related logic of kvm_mmu_max_mapping_level() into a
> new helper so that KVMGT can determine whether or not mapping a 2MiB
> page into the guest is (dis)allowed per KVM's memslots.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sea...@google.com>
> ---
> arch/x86/kvm/mmu/mmu.c | 21 +++++++++++++++------
> arch/x86/kvm/mmu/mmu_internal.h | 2 ++
> 2 files changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index
> c8ebe542c565..4685c80e441b 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -3083,20 +3083,29 @@ static int host_pfn_mapping_level(struct kvm
> *kvm, gfn_t gfn,
> return level;
> }
>
> +int kvm_mmu_max_slot_mapping_level(const struct kvm_memory_slot *slot,
> + gfn_t gfn, int max_level)
It seems more common to be named "kvm_mmu_slot_max_mapping_level"
(we have other kvm_mmu_slot_* functions defined already)
> +{
> + struct kvm_lpage_info *linfo;
> +
> + for ( ; max_level > PG_LEVEL_4K; max_level--) {
> + linfo = lpage_info_slot(gfn, slot, max_level);
> + if (!linfo->disallow_lpage)
> + break;
> + }
> + return max_level;
> +}
> +
> int kvm_mmu_max_mapping_level(struct kvm *kvm,
> const struct kvm_memory_slot *slot, gfn_t gfn,
> int max_level)
> {
> - struct kvm_lpage_info *linfo;
> int host_level;
>
> max_level = min(max_level, max_huge_page_level);
Better to also have this min(,) moved to the helper?
E.g. if max_huge_page_level has been 4KB, no need to check into lpage_info in
the helper.
