From 22b1d57b032cea4d612746473ed28cb20665d876 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 8 Jan 2020 12:24:35 -0800 Subject: [PATCH] KVM: x86/mmu: Enforce max_level on HugeTLB mappings Limit KVM's mapping level for HugeTLB based on its calculated max_level. The max_level check prior to invoking host_mapping_level() only filters out the case where KVM cannot create a 2mb mapping, it doesn't handle the scenario where KVM can create a 2mb but not 1gb mapping, and the host is using a 1gb HugeTLB mapping. Fixes: 2f57b7051fe8 ("KVM: x86/mmu: Persist gfn_lpage_is_disallowed() to max_level") Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index b9052c7..db597f5 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1330,7 +1330,7 @@ gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn, static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn, int *max_levelp) { - int max_level = *max_levelp; + int host_level, max_level = *max_levelp; struct kvm_memory_slot *slot; if (unlikely(max_level == PT_PAGE_TABLE_LEVEL)) @@ -1362,7 +1362,8 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn, * So, do not propagate host_mapping_level() to max_level as KVM can * still promote the guest mapping to a huge page in the THP case. */ - return host_mapping_level(vcpu->kvm, large_gfn); + host_level = host_mapping_level(vcpu->kvm, large_gfn); + return min(host_level, max_level); } /* -- 2.7.4