Commit d041b5ea authored by Ilias Stamatis's avatar Ilias Stamatis Committed by Paolo Bonzini
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KVM: nVMX: Enable nested TSC scaling 



Calculate the TSC offset and multiplier on nested transitions and expose
the TSC scaling feature to L1.

Signed-off-by: default avatarIlias Stamatis <ilstam@amazon.com>
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210526184418.28881-11-ilstam@amazon.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 1ab9287a

arch/x86/kvm/vmx/nested.c

+18 −6
Original line number Diff line number Diff line
@@ -2277,7 +2277,8 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) 
				  SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE |

				  SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |

				  SECONDARY_EXEC_APIC_REGISTER_VIRT |

				  SECONDARY_EXEC_ENABLE_VMFUNC);

				  SECONDARY_EXEC_ENABLE_VMFUNC |

				  SECONDARY_EXEC_TSC_SCALING);

		if (nested_cpu_has(vmcs12,

				   CPU_BASED_ACTIVATE_SECONDARY_CONTROLS))

			exec_control |= vmcs12->secondary_vm_exec_control;
@@ -2532,6 +2533,15 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 
		vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat);

	}



	vcpu->arch.tsc_offset = kvm_calc_nested_tsc_offset(

			vcpu->arch.l1_tsc_offset,

			vmx_get_l2_tsc_offset(vcpu),

			vmx_get_l2_tsc_multiplier(vcpu));



	vcpu->arch.tsc_scaling_ratio = kvm_calc_nested_tsc_multiplier(

			vcpu->arch.l1_tsc_scaling_ratio,

			vmx_get_l2_tsc_multiplier(vcpu));



	vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset);

	if (kvm_has_tsc_control)

		vmcs_write64(TSC_MULTIPLIER, vcpu->arch.tsc_scaling_ratio);
@@ -3353,8 +3363,6 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, 
	}



	enter_guest_mode(vcpu);

	if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETTING)

		vcpu->arch.tsc_offset += vmcs12->tsc_offset;



	if (prepare_vmcs02(vcpu, vmcs12, &entry_failure_code)) {

		exit_reason.basic = EXIT_REASON_INVALID_STATE;
@@ -4462,8 +4470,11 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason, 
	if (nested_cpu_has_preemption_timer(vmcs12))

		hrtimer_cancel(&to_vmx(vcpu)->nested.preemption_timer);



	if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETTING)

		vcpu->arch.tsc_offset -= vmcs12->tsc_offset;

	if (nested_cpu_has(vmcs12, CPU_BASED_USE_TSC_OFFSETTING)) {

		vcpu->arch.tsc_offset = vcpu->arch.l1_tsc_offset;

		if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_TSC_SCALING))

			vcpu->arch.tsc_scaling_ratio = vcpu->arch.l1_tsc_scaling_ratio;

	}



	if (likely(!vmx->fail)) {

		sync_vmcs02_to_vmcs12(vcpu, vmcs12);
@@ -6473,7 +6484,8 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps) 
		SECONDARY_EXEC_RDRAND_EXITING |

		SECONDARY_EXEC_ENABLE_INVPCID |

		SECONDARY_EXEC_RDSEED_EXITING |

		SECONDARY_EXEC_XSAVES;

		SECONDARY_EXEC_XSAVES |

		SECONDARY_EXEC_TSC_SCALING;



	/*

	 * We can emulate "VMCS shadowing," even if the hardware