From df7e0681dd8acfa8d07816eaef232ded816d8a8c Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 20 May 2020 08:37:37 -0400 Subject: [PATCH] KVM: nVMX: always update CR3 in VMCS vmx_load_mmu_pgd is delaying the write of GUEST_CR3 to prepare_vmcs02 as an optimization, but this is only correct before the nested vmentry. If userspace is modifying CR3 with KVM_SET_SREGS after the VM has already been put in guest mode, the value of CR3 will not be updated. Remove the optimization, which almost never triggers anyway. Fixes: 04f11ef45810 ("KVM: nVMX: Always write vmcs02.GUEST_CR3 during nested VM-Enter") Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/vmx.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index b3a41645e157..7b55dc6230a9 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3085,10 +3085,7 @@ void vmx_load_mmu_pgd(struct kvm_vcpu *vcpu, unsigned long pgd) spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock); } - /* Loading vmcs02.GUEST_CR3 is handled by nested VM-Enter. */ - if (is_guest_mode(vcpu)) - update_guest_cr3 = false; - else if (!enable_unrestricted_guest && !is_paging(vcpu)) + if (!enable_unrestricted_guest && !is_paging(vcpu)) guest_cr3 = to_kvm_vmx(kvm)->ept_identity_map_addr; else if (test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail)) guest_cr3 = vcpu->arch.cr3;