diff mbox series

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

Message ID d99863c474b8a3d9e413fbf940bf6891d2ce319e.1705965635.git.isaku.yamahata@intel.com (mailing list archive)
State New, archived
Headers show
Series KVM TDX basic feature support | expand

Commit Message

Isaku Yamahata Jan. 22, 2024, 11:53 p.m. UTC 
From: Sean Christopherson <sean.j.christopherson@intel.com>

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@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Acked-by: Kai Huang <kai.huang@intel.com>
---
 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(-)

Comments

Binbin Wu Jan. 28, 2024, 2:12 p.m. UTC | #1 
On 1/23/2024 7:53 AM, isaku.yamahata@intel.com wrote:
> From: Sean Christopherson <sean.j.christopherson@intel.com>
>
> 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@intel.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Acked-by: Kai Huang <kai.huang@intel.com>
> ---
>   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;

Although only TDX need special handling for now, and TDX always use TDP,
but it doesn't necessarily to be TDP, right?
When the value is assigned to kvm_page_fault.max_level, it is also used for
non-TDP code path.

>   	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,
>   	};
Paolo Bonzini Feb. 12, 2024, 10:34 a.m. UTC | #2 
On Tue, Jan 23, 2024 at 12:55 AM <isaku.yamahata@intel.com> wrote:
>
> From: Sean Christopherson <sean.j.christopherson@intel.com>
>
> 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@intel.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Acked-by: Kai Huang <kai.huang@intel.com>

Please reimplement this on top of "KVM: x86: Add gmem hook for
determining max NPT mapping level" from the SEV-SNP series.

Paolo


> ---
>  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
>
diff mbox series

Patch

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,
 	};