From: Paolo Bonzini pbonzini@redhat.com

commit 112e66017bff7f2837030f34c2bc19501e9212d5 upstream.

The effective values of the guest CR0 and CR4 registers may differ from those included in the VMCS12. In particular, disabling EPT forces CR4.PAE=1 and disabling unrestricted guest mode forces CR0.PG=CR0.PE=1.

Therefore, checks on these bits cannot be delegated to the processor and must be performed by KVM.

Reported-by: Reima ISHII ishiir@g.ecc.u-tokyo.ac.jp Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com [OP: drop CC() macro calls, as tracing is not implemented in 4.19] [OP: adjust "return -EINVAL" -> "return 1" to match current return logic] Signed-off-by: Ovidiu Panait ovidiu.panait@windriver.com --- arch/x86/kvm/vmx/vmx.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index ec821a5d131a..265e70b0eb79 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -12752,7 +12752,7 @@ static int nested_vmx_check_vmcs_link_ptr(struct kvm_vcpu *vcpu, static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, u32 *exit_qual) { - bool ia32e; + bool ia32e = !!(vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE);

*exit_qual = ENTRY_FAIL_DEFAULT;

@@ -12765,6 +12765,13 @@ static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, return 1; }

+ if ((vmcs12->guest_cr0 & (X86_CR0_PG | X86_CR0_PE)) == X86_CR0_PG) + return 1; + + if ((ia32e && !(vmcs12->guest_cr4 & X86_CR4_PAE)) || + (ia32e && !(vmcs12->guest_cr0 & X86_CR0_PG))) + return 1; + /* * If the load IA32_EFER VM-entry control is 1, the following checks * are performed on the field for the IA32_EFER MSR: @@ -12776,7 +12783,6 @@ static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, */ if (to_vmx(vcpu)->nested.nested_run_pending && (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)) { - ia32e = (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) != 0; if (!kvm_valid_efer(vcpu, vmcs12->guest_ia32_efer) || ia32e != !!(vmcs12->guest_ia32_efer & EFER_LMA) || ((vmcs12->guest_cr0 & X86_CR0_PG) &&