From 992edeaefed682511bd173dabd2f54b1ce5387df Mon Sep 17 00:00:00 2001 From: Liran Alon Date: Wed, 20 Nov 2019 14:24:52 +0200 Subject: [PATCH] KVM: nVMX: Assume TLB entries of L1 and L2 are tagged differently if L0 use EPT Since commit 1313cc2bd8f6 ("kvm: mmu: Add guest_mode to kvm_mmu_page_role"), guest_mode was added to mmu-role and therefore if L0 use EPT, it will always run L1 and L2 with different EPTP. i.e. EPTP01!=EPTP02. Because TLB entries are tagged with EP4TA, KVM can assume TLB entries populated while running L2 are tagged differently than TLB entries populated while running L1. Therefore, update nested_has_guest_tlb_tag() to consider if L0 use EPT instead of if L1 use EPT. Reviewed-by: Joao Martins Reviewed-by: Krish Sadhukhan Signed-off-by: Liran Alon Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index f161a941cb09..dc06e67be017 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -1126,7 +1126,9 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne * populated by L2 differently than TLB entries populated * by L1. * - * If L1 uses EPT, then TLB entries are tagged with different EPTP. + * If L0 uses EPT, L1 and L2 run with different EPTP because + * guest_mode is part of kvm_mmu_page_role. Thus, TLB entries + * are tagged with different EPTP. * * If L1 uses VPID and we allocated a vpid02, TLB entries are tagged * with different VPID (L1 entries are tagged with vmx->vpid @@ -1136,7 +1138,7 @@ static bool nested_has_guest_tlb_tag(struct kvm_vcpu *vcpu) { struct vmcs12 *vmcs12 = get_vmcs12(vcpu); - return nested_cpu_has_ept(vmcs12) || + return enable_ept || (nested_cpu_has_vpid(vmcs12) && to_vmx(vcpu)->nested.vpid02); } -- 2.45.2