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Commit 5a6a9748 authored by David Matlack's avatar David Matlack Committed by Paolo Bonzini
Browse files

KVM: nVMX: load GUEST_EFER after GUEST_CR0 during emulated VM-entry 



vmx_set_cr0() modifies GUEST_EFER and "IA-32e mode guest" in the current
VMCS. Call vmx_set_efer() after vmx_set_cr0() so that emulated VM-entry
is more faithful to VMCS12.

This patch correctly causes VM-entry to fail when "IA-32e mode guest" is
1 and GUEST_CR0.PG is 0. Previously this configuration would succeed and
"IA-32e mode guest" would silently be disabled by KVM.

Signed-off-by: default avatarDavid Matlack <dmatlack@google.com>
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent 8322ebbb

arch/x86/kvm/vmx.c

+9 −9
Original line number Diff line number Diff line
@@ -10272,15 +10272,6 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) 
		nested_ept_init_mmu_context(vcpu);

	}



	if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)

		vcpu->arch.efer = vmcs12->guest_ia32_efer;

	else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)

		vcpu->arch.efer |= (EFER_LMA | EFER_LME);

	else

		vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);

	/* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */

	vmx_set_efer(vcpu, vcpu->arch.efer);



	/*

	 * This sets GUEST_CR0 to vmcs12->guest_cr0, with possibly a modified

	 * TS bit (for lazy fpu) and bits which we consider mandatory enabled.
@@ -10295,6 +10286,15 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) 
	vmx_set_cr4(vcpu, vmcs12->guest_cr4);

	vmcs_writel(CR4_READ_SHADOW, nested_read_cr4(vmcs12));



	if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)

		vcpu->arch.efer = vmcs12->guest_ia32_efer;

	else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)

		vcpu->arch.efer |= (EFER_LMA | EFER_LME);

	else

		vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);

	/* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */

	vmx_set_efer(vcpu, vcpu->arch.efer);



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

	kvm_set_cr3(vcpu, vmcs12->guest_cr3);

	kvm_mmu_reset_context(vcpu);