Commit b2e02f82 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Sean Christopherson
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KVM: nVMX: Split off helper for emulating VMCLEAR on Hyper-V eVMCS 



To avoid overloading handle_vmclear() with Hyper-V specific details and to
prepare the code to making Hyper-V emulation optional, create a dedicated
nested_evmcs_handle_vmclear() helper.

No functional change intended.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Tested-by: default avatarJeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20231205103630.1391318-9-vkuznets@redhat.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent af9d544a

arch/x86/kvm/vmx/nested.c

+24 −14
Original line number Diff line number Diff line
@@ -243,6 +243,29 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu) 
	}

}



static bool nested_evmcs_handle_vmclear(struct kvm_vcpu *vcpu, gpa_t vmptr)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	/*

	 * When Enlightened VMEntry is enabled on the calling CPU we treat

	 * memory area pointer by vmptr as Enlightened VMCS (as there's no good

	 * way to distinguish it from VMCS12) and we must not corrupt it by

	 * writing to the non-existent 'launch_state' field. The area doesn't

	 * have to be the currently active EVMCS on the calling CPU and there's

	 * nothing KVM has to do to transition it from 'active' to 'non-active'

	 * state. It is possible that the area will stay mapped as

	 * vmx->nested.hv_evmcs but this shouldn't be a problem.

	 */

	if (!guest_cpuid_has_evmcs(vcpu) ||

	    !evmptr_is_valid(nested_get_evmptr(vcpu)))

		return false;



	if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr)

		nested_release_evmcs(vcpu);



	return true;

}



static void vmx_sync_vmcs_host_state(struct vcpu_vmx *vmx,

				     struct loaded_vmcs *prev)

{
@@ -5286,18 +5309,7 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) 
	if (vmptr == vmx->nested.vmxon_ptr)

		return nested_vmx_fail(vcpu, VMXERR_VMCLEAR_VMXON_POINTER);



	/*

	 * When Enlightened VMEntry is enabled on the calling CPU we treat

	 * memory area pointer by vmptr as Enlightened VMCS (as there's no good

	 * way to distinguish it from VMCS12) and we must not corrupt it by

	 * writing to the non-existent 'launch_state' field. The area doesn't

	 * have to be the currently active EVMCS on the calling CPU and there's

	 * nothing KVM has to do to transition it from 'active' to 'non-active'

	 * state. It is possible that the area will stay mapped as

	 * vmx->nested.hv_evmcs but this shouldn't be a problem.

	 */

	if (likely(!guest_cpuid_has_evmcs(vcpu) ||

		   !evmptr_is_valid(nested_get_evmptr(vcpu)))) {

	if (likely(!nested_evmcs_handle_vmclear(vcpu, vmptr))) {

		if (vmptr == vmx->nested.current_vmptr)

			nested_release_vmcs12(vcpu);
@@ -5314,8 +5326,6 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) 
					   vmptr + offsetof(struct vmcs12,

							    launch_state),

					   &zero, sizeof(zero));

	} else if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr) {

		nested_release_evmcs(vcpu);

	}



	return nested_vmx_succeed(vcpu);