From f8aa7e3958bc433087ae7b9d7f24a92036c41141 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 20 Mar 2020 14:27:59 -0700 Subject: [PATCH] KVM: nVMX: Invalidate all EPTP contexts when emulating INVEPT for L1 Free all L2 (guest_mmu) roots when emulating INVEPT for L1. Outstanding changes to the EPT tables managed by L1 need to be recognized, and relying on KVM to always flush L2's EPTP context on nested VM-Enter is dangerous. Similar to handle_invpcid(), rely on kvm_mmu_free_roots() to do a remote TLB flush if necessary, e.g. if L1 has never entered L2 then there is nothing to be done. Nuking all L2 roots is overkill for the single-context variant, but it's the safe and easy bet. A more precise zap mechanism will be added in the future. Add a TODO to call out that KVM only needs to invalidate affected contexts. Fixes: 14c07ad89f4d ("x86/kvm/mmu: introduce guest_mmu") Reported-by: Jim Mattson Signed-off-by: Sean Christopherson Message-Id: <20200320212833.3507-4-sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index dc7d8104b58e..7ecb555e385a 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5161,12 +5161,16 @@ static int handle_invept(struct kvm_vcpu *vcpu) if (!nested_vmx_check_eptp(vcpu, operand.eptp)) return nested_vmx_failValid(vcpu, VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID); + + /* TODO: sync only the target EPTP context. */ fallthrough; case VMX_EPT_EXTENT_GLOBAL: - /* - * TODO: Sync the necessary shadow EPT roots here, rather than - * at the next emulated VM-entry. - */ + /* + * Nested EPT roots are always held through guest_mmu, + * not root_mmu. + */ + kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu, + KVM_MMU_ROOTS_ALL); break; default: BUG_ON(1);