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Commit 7ad658b6 authored by Ladi Prosek's avatar Ladi Prosek Committed by Paolo Bonzini
Browse files

KVM: nVMX: fix nested EPT detection 



The nested_ept_enabled flag introduced in commit 7ca29de2 was not
computed correctly. We are interested only in L1's EPT state, not the
the combined L0+L1 value.

In particular, if L0 uses EPT but L1 does not, nested_ept_enabled must
be false to make sure that PDPSTRs are loaded based on CR3 as usual,
because the special case described in 26.3.2.4 Loading Page-Directory-
Pointer-Table Entries does not apply.

Fixes: 7ca29de2 ("KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT")
Cc: qemu-stable@nongnu.org
Reported-by: default avatarWanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarLadi Prosek <lprosek@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 0292e169

arch/x86/kvm/vmx.c

+1 −4
Original line number Diff line number Diff line
@@ -9992,7 +9992,6 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 
{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	u32 exec_control;

	bool nested_ept_enabled = false;



	vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);

	vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
@@ -10139,8 +10138,6 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 
				vmcs12->guest_intr_status);

		}



		nested_ept_enabled = (exec_control & SECONDARY_EXEC_ENABLE_EPT) != 0;



		/*

		 * Write an illegal value to APIC_ACCESS_ADDR. Later,

		 * nested_get_vmcs12_pages will either fix it up or
@@ -10303,7 +10300,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 
	vmx_set_efer(vcpu, vcpu->arch.efer);



	/* Shadow page tables on either EPT or shadow page tables. */

	if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_ept_enabled,

	if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_cpu_has_ept(vmcs12),

				entry_failure_code))

		return 1;