[PATCH v18 041/121] KVM: x86/mmu: Allow per-VM override of the TDP max page level

[isaku . yamahata]

From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

TDX requires special handling to support large private page.  For
simplicity, only support 4K page for TD guest for now.  Add per-VM maximum
page level support to support different maximum page sizes for TD guest and
conventional VMX guest.

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Acked-by: Kai Huang <kai.huang@xxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/mmu/mmu.c          | 2 ++
 arch/x86/kvm/mmu/mmu_internal.h | 2 +-
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 430d7bd7c37c..313519edd79e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1283,6 +1283,7 @@ struct kvm_arch {
 	unsigned long n_requested_mmu_pages;
 	unsigned long n_max_mmu_pages;
 	unsigned int indirect_shadow_pages;
+	int tdp_max_page_level;
 	u8 mmu_valid_gen;
 	struct hlist_head mmu_page_hash[KVM_NUM_MMU_PAGES];
 	struct list_head active_mmu_pages;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 54d4c8f1ba68..e93bc16a5e9b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6307,6 +6307,8 @@ void kvm_mmu_init_vm(struct kvm *kvm)
 
 	kvm->arch.split_desc_cache.kmem_cache = pte_list_desc_cache;
 	kvm->arch.split_desc_cache.gfp_zero = __GFP_ZERO;
+
+	kvm->arch.tdp_max_page_level = KVM_MAX_HUGEPAGE_LEVEL;
 }
 
 static void mmu_free_vm_memory_caches(struct kvm *kvm)
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 0443bfcf5d9c..2b9377442927 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -296,7 +296,7 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 		.nx_huge_page_workaround_enabled =
 			is_nx_huge_page_enabled(vcpu->kvm),
 
-		.max_level = KVM_MAX_HUGEPAGE_LEVEL,
+		.max_level = vcpu->kvm->arch.tdp_max_page_level,
 		.req_level = PG_LEVEL_4K,
 		.goal_level = PG_LEVEL_4K,
 	};
-- 
2.25.1