2023-01-12 16:48:11

by Isaku Yamahata

Subject: [PATCH v11 035/113] KVM: x86/mmu: Allow per-VM override of the TDP max page level

From: Sean Christopherson <[email protected]>

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 <[email protected]>
Signed-off-by: Isaku Yamahata <[email protected]>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/mmu/mmu.c | 1 +
arch/x86/kvm/mmu/mmu_internal.h | 2 +-
3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 807da4b95aba..f5b51bdef0c6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1217,6 +1217,7 @@ 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 5b111a325434..801ef6c41847 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6141,6 +6141,7 @@ int 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;
return 0;
}

diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 5ccf08183b00..6767bc9b7c5c 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -276,7 +276,7 @@ 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

2023-01-16 11:41:27

by Kai Huang

Subject: Re: [PATCH v11 035/113] KVM: x86/mmu: Allow per-VM override of the TDP max page level

On Thu, 2023-01-12 at 08:31 -0800, [email protected] wrote:
> From: Sean Christopherson <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Isaku Yamahata <[email protected]>

Acked-by: Kai Huang <[email protected]>