[PATCH v7 045/102] KVM: x86/tdp_mmu: refactor kvm_tdp_mmu_map()

isaku.yamahata
2022-06-27T21:56:52Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

Factor out non-leaf SPTE population logic from kvm_tdp_mmu_map(). MapGPA
hypercall needs to populate non-leaf SPTE to record which GPA, private or
shared, is allowed in the leaf EPT entry.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/kvm/mmu/tdp_mmu.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index b2568b062faa..d874c79ab96c 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1167,6 +1167,24 @@ static int tdp_mmu_link_sp(struct kvm *kvm, struct tdp_iter *iter,
return 0;
}

+static int tdp_mmu_populate_nonleaf(
+ struct kvm_vcpu *vcpu, struct tdp_iter *iter, bool account_nx)
+{
+ struct kvm_mmu_page *sp;
+ int ret;
+
+ WARN_ON(is_shadow_present_pte(iter->old_spte));
+ WARN_ON(is_removed_spte(iter->old_spte));
+
+ sp = tdp_mmu_alloc_sp(vcpu);
+ tdp_mmu_init_child_sp(sp, iter);
+
+ ret = tdp_mmu_link_sp(vcpu->kvm, iter, sp, account_nx, true);
+ if (ret)
+ tdp_mmu_free_sp(sp);
+ return ret;
+}
+
/*
* Handle a TDP page fault (NPT/EPT violation/misconfiguration) by installing
* page tables and SPTEs to translate the faulting guest physical address.
@@ -1175,7 +1193,6 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
{
struct kvm_mmu *mmu = vcpu->arch.mmu;
struct tdp_iter iter;
- struct kvm_mmu_page *sp;
int ret;

kvm_mmu_hugepage_adjust(vcpu, fault);
@@ -1221,13 +1238,8 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
if (is_removed_spte(iter.old_spte))
break;

- sp = tdp_mmu_alloc_sp(vcpu);
- tdp_mmu_init_child_sp(sp, &iter);
-
- if (tdp_mmu_link_sp(vcpu->kvm, &iter, sp, account_nx, true)) {
- tdp_mmu_free_sp(sp);
+ if (tdp_mmu_populate_nonleaf(vcpu, &iter, account_nx))
break;
- }
}
}

--
2.25.1