On Fri, 2022-03-04 at 11:49 -0800, isaku.yamahata@xxxxxxxxx wrote:
> From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
>
> Add a private pointer to kvm_mmu_page for private EPT.
>
> To resolve KVM page fault on private GPA, it will allocate additional page
> for Secure EPT in addition to private EPT. Add memory allocator for it and
> topup its memory allocator before resolving KVM page fault similar to
> shared EPT page. Allocation of those memory will be done for TDP MMU by
> alloc_tdp_mmu_page(). Freeing those memory will be done for TDP MMU on
> behalf of kvm_tdp_mmu_zap_all() called by kvm_mmu_zap_all(). Private EPT
> page needs to carry one more page used for Secure EPT in addition to the
> private EPT page. Add private pointer to struct kvm_mmu_page for that
> purpose and Add helper functions to allocate/free a page for Secure EPT.
> Also add helper functions to check if a given kvm_mmu_page is private.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> ---
> arch/x86/include/asm/kvm_host.h | 1 +
> arch/x86/kvm/mmu/mmu.c | 9 ++++
> arch/x86/kvm/mmu/mmu_internal.h | 84 +++++++++++++++++++++++++++++++++
> arch/x86/kvm/mmu/tdp_mmu.c | 3 ++
> 4 files changed, 97 insertions(+)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index fcab2337819c..0c8cc7d73371 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -689,6 +689,7 @@ struct kvm_vcpu_arch {
> struct kvm_mmu_memory_cache mmu_shadow_page_cache;
> struct kvm_mmu_memory_cache mmu_gfn_array_cache;
> struct kvm_mmu_memory_cache mmu_page_header_cache;
> + struct kvm_mmu_memory_cache mmu_private_sp_cache;
>
> /*
> * QEMU userspace and the guest each have their own FPU state.
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 6e9847b1124b..8def8b97978f 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -758,6 +758,13 @@ static int mmu_topup_shadow_page_cache(struct kvm_vcpu *vcpu)
> struct kvm_mmu_memory_cache *mc = &vcpu->arch.mmu_shadow_page_cache;
> int start, end, i, r;
>
> + if (kvm_gfn_stolen_mask(vcpu->kvm)) {
Please get rid of kvm_gfn_stolen_mask().
> + r = kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_private_sp_cache,
> + PT64_ROOT_MAX_LEVEL);
> + if (r)
> + return r;
> + }
> +
> if (shadow_init_value)
> start = kvm_mmu_memory_cache_nr_free_objects(mc);
>
