[RFC PATCH 02/13] KVM: TDP_MMU: Go to next level if smaller private mapping exists

From: isaku . yamahata
Date: Sun Aug 07 2022 - 18:32:11 EST


From: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>

Cannot map a private page as large page if any smaller mapping exists.

It has to wait for all the not-mapped smaller page to be mapped and
promote it to larger mapping.

Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
arch/x86/kvm/mmu/tdp_mmu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index f2461deba2dc..faf278e0c740 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1322,7 +1322,8 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
}

tdp_mmu_for_each_pte(iter, mmu, is_private, raw_gfn, raw_gfn + 1) {
- if (fault->nx_huge_page_workaround_enabled)
+ if (fault->nx_huge_page_workaround_enabled ||
+ kvm_gfn_shared_mask(vcpu->kvm))
disallowed_hugepage_adjust(fault, iter.old_spte, iter.level);

if (iter.level == fault->goal_level)
--
2.25.1