On 3/4/22 20:49, isaku.yamahata@xxxxxxxxx wrote:
From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
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@xxxxxxxxx>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
and feel free to rebase/resubmit this one, with subject "KVM:
x86/tdp_mmu: extract tdp_mmu_populate_nonleaf()".
Paolo
---
arch/x86/kvm/mmu/tdp_mmu.c | 48 ++++++++++++++++++++++++--------------
1 file changed, 30 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index b6ec2f112c26..8db262440d5c 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -955,6 +955,31 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu,
return ret;
}
+static bool tdp_mmu_populate_nonleaf(
+ struct kvm_vcpu *vcpu, struct tdp_iter *iter, bool account_nx)
+{
+ struct kvm_mmu_page *sp;
+ u64 *child_pt;
+ u64 new_spte;
+
+ WARN_ON(is_shadow_present_pte(iter->old_spte));
+ WARN_ON(is_removed_spte(iter->old_spte));
+
+ sp = alloc_tdp_mmu_page(vcpu, iter->gfn, iter->level - 1);
+ child_pt = sp->spt;
+
+ new_spte = make_nonleaf_spte(child_pt, !shadow_accessed_mask);
+
+ if (!tdp_mmu_set_spte_atomic(vcpu->kvm, iter, new_spte)) {
+ tdp_mmu_free_sp(sp);
+ return false;
+ }
+
+ tdp_mmu_link_page(vcpu->kvm, sp, account_nx);
+ trace_kvm_mmu_get_page(sp, true);
+ return true;
+}
+
/*
* Handle a TDP page fault (NPT/EPT violation/misconfiguration) by installing
* page tables and SPTEs to translate the faulting guest physical address.
@@ -963,9 +988,6 @@ 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;
- u64 *child_pt;
- u64 new_spte;
int ret;
kvm_mmu_hugepage_adjust(vcpu, fault);
@@ -1000,6 +1022,8 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
}
if (!is_shadow_present_pte(iter.old_spte)) {
+ bool account_nx;
+
/*
* If SPTE has been frozen by another thread, just
* give up and retry, avoiding unnecessary page table
@@ -1008,22 +1032,10 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
if (is_removed_spte(iter.old_spte))
break;
- sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level - 1);
- child_pt = sp->spt;
-
- new_spte = make_nonleaf_spte(child_pt,
- !shadow_accessed_mask);
-
- if (tdp_mmu_set_spte_atomic(vcpu->kvm, &iter, new_spte)) {
- tdp_mmu_link_page(vcpu->kvm, sp,
- fault->huge_page_disallowed &&
- fault->req_level >= iter.level);
-
- trace_kvm_mmu_get_page(sp, true);
- } else {
- tdp_mmu_free_sp(sp);
+ account_nx = fault->huge_page_disallowed &&
+ fault->req_level >= iter.level;
+ if (!tdp_mmu_populate_nonleaf(vcpu, &iter, account_nx))
break;
- }
}
}
