Commit 451d39e8 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: VMX: Move Hyper-V eVMCS initialization to helper 



Move Hyper-V's eVMCS initialization to a dedicated helper to clean up
vmx_init(), and add a comment to call out that the Hyper-V init code
doesn't need to be unwound if vmx_init() ultimately fails.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Reviewed-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20221130230934.1014142-13-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent da66de44

arch/x86/kvm/vmx/vmx.c

+43 −30
Original line number Diff line number Diff line
@@ -523,6 +523,8 @@ static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx) 
static unsigned long host_idt_base;



#if IS_ENABLED(CONFIG_HYPERV)

static struct kvm_x86_ops vmx_x86_ops __initdata;



static bool __read_mostly enlightened_vmcs = true;

module_param(enlightened_vmcs, bool, 0444);
@@ -551,6 +553,43 @@ static int hv_enable_l2_tlb_flush(struct kvm_vcpu *vcpu) 
	return 0;

}



static __init void hv_init_evmcs(void)

{

	int cpu;



	if (!enlightened_vmcs)

		return;



	/*

	 * Enlightened VMCS usage should be recommended and the host needs

	 * to support eVMCS v1 or above.

	 */

	if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED &&

	    (ms_hyperv.nested_features & HV_X64_ENLIGHTENED_VMCS_VERSION) >=

	     KVM_EVMCS_VERSION) {



		/* Check that we have assist pages on all online CPUs */

		for_each_online_cpu(cpu) {

			if (!hv_get_vp_assist_page(cpu)) {

				enlightened_vmcs = false;

				break;

			}

		}



		if (enlightened_vmcs) {

			pr_info("KVM: vmx: using Hyper-V Enlightened VMCS\n");

			static_branch_enable(&enable_evmcs);

		}



		if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH)

			vmx_x86_ops.enable_l2_tlb_flush

				= hv_enable_l2_tlb_flush;



	} else {

		enlightened_vmcs = false;

	}

}



static void hv_reset_evmcs(void)

{

	struct hv_vp_assist_page *vp_ap;
@@ -577,6 +616,7 @@ static void hv_reset_evmcs(void) 
}



#else /* IS_ENABLED(CONFIG_HYPERV) */

static void hv_init_evmcs(void) {}

static void hv_reset_evmcs(void) {}

#endif /* IS_ENABLED(CONFIG_HYPERV) */
@@ -8543,38 +8583,11 @@ static int __init vmx_init(void) 
{

	int r, cpu;



#if IS_ENABLED(CONFIG_HYPERV)

	/*

	 * Enlightened VMCS usage should be recommended and the host needs

	 * to support eVMCS v1 or above. We can also disable eVMCS support

	 * with module parameter.

	 * Note, hv_init_evmcs() touches only VMX knobs, i.e. there's nothing

	 * to unwind if a later step fails.

	 */

	if (enlightened_vmcs &&

	    ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED &&

	    (ms_hyperv.nested_features & HV_X64_ENLIGHTENED_VMCS_VERSION) >=

	    KVM_EVMCS_VERSION) {



		/* Check that we have assist pages on all online CPUs */

		for_each_online_cpu(cpu) {

			if (!hv_get_vp_assist_page(cpu)) {

				enlightened_vmcs = false;

				break;

			}

		}



		if (enlightened_vmcs) {

			pr_info("KVM: vmx: using Hyper-V Enlightened VMCS\n");

			static_branch_enable(&enable_evmcs);

		}



		if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH)

			vmx_x86_ops.enable_l2_tlb_flush

				= hv_enable_l2_tlb_flush;



	} else {

		enlightened_vmcs = false;

	}

#endif

	hv_init_evmcs();



	r = kvm_init(&vmx_init_ops, sizeof(struct vcpu_vmx),

		     __alignof__(struct vcpu_vmx), THIS_MODULE);