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Commit 3df5c37e authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: nVMX: try to set EFER bits correctly when initializing controls 



VM_ENTRY_IA32E_MODE and VM_{ENTRY,EXIT}_LOAD_IA32_EFER will be
explicitly set/cleared as needed by vmx_set_efer(), but attempt
to get the bits set correctly when intializing the control fields.
Setting the value correctly can avoid multiple VMWrites.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 02343cf2

arch/x86/kvm/vmx.c

+35 −16
Original line number Diff line number Diff line
@@ -11972,6 +11972,17 @@ static bool nested_has_guest_tlb_tag(struct kvm_vcpu *vcpu) 
	       (nested_cpu_has_vpid(vmcs12) && to_vmx(vcpu)->nested.vpid02);

}



static u64 nested_vmx_calc_efer(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)

{

	if (vmx->nested.nested_run_pending &&

	    (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER))

		return vmcs12->guest_ia32_efer;

	else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)

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

	else

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

}



static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -12116,6 +12127,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 
{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	u32 exec_control, vmcs12_exec_ctrl;

	u64 guest_efer;



	if (vmx->nested.dirty_vmcs12) {

		prepare_vmcs02_full(vcpu, vmcs12);
@@ -12264,19 +12276,32 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 
	vcpu->arch.cr0_guest_owned_bits &= ~vmcs12->cr0_guest_host_mask;

	vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);



	/*

	 * vmcs12's VM_{ENTRY,EXIT}_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE

	 * are emulated by vmx_set_efer(), below, but speculate on the

	 * related bits (if supported by the CPU) in the hope that we can

	 * avoid VMWrites during vmx_set_efer().

	 */

	guest_efer = nested_vmx_calc_efer(vmx, vmcs12);



	/* L2->L1 exit controls are emulated - the hardware exit is to L0 so

	 * we should use its exit controls. Note that VM_EXIT_LOAD_IA32_EFER

	 * bits are further modified by vmx_set_efer() below.

	 */

	vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl);

	exec_control = vmcs_config.vmexit_ctrl;

	if (cpu_has_load_ia32_efer && guest_efer != host_efer)

		exec_control |= VM_EXIT_LOAD_IA32_EFER;

	vm_exit_controls_init(vmx, exec_control);



	/* vmcs12's VM_ENTRY_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE are

	 * emulated by vmx_set_efer(), below.

	 */

	vm_entry_controls_init(vmx, 

		(vmcs12->vm_entry_controls & ~VM_ENTRY_LOAD_IA32_EFER &

			~VM_ENTRY_IA32E_MODE) |

		(vmcs_config.vmentry_ctrl & ~VM_ENTRY_IA32E_MODE));

	exec_control = (vmcs12->vm_entry_controls | vmcs_config.vmentry_ctrl) &

			~VM_ENTRY_IA32E_MODE & ~VM_ENTRY_LOAD_IA32_EFER;

	if (cpu_has_load_ia32_efer) {

		if (guest_efer & EFER_LMA)

			exec_control |= VM_ENTRY_IA32E_MODE;

		if (guest_efer != host_efer)

			exec_control |= VM_ENTRY_LOAD_IA32_EFER;

	}

	vm_entry_controls_init(vmx, exec_control);



	if (vmx->nested.nested_run_pending &&

	    (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PAT)) {
@@ -12350,14 +12375,8 @@ static int 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 (vmx->nested.nested_run_pending &&

	    (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 */

	vcpu->arch.efer = guest_efer;

	/* Note: may modify VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */

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



	/*