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Commit 495adb06 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Greg Kroah-Hartman
Browse files

KVM: nVMX: add missing consistency checks for CR0 and CR4 



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: default avatarReima ISHII <ishiir@g.ecc.u-tokyo.ac.jp>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaolo 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: default avatarOvidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 08096e53

arch/x86/kvm/vmx/vmx.c

+8 −2
Original line number Diff line number Diff line
@@ -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) &&