linux-kernel - Re: [PATCH v2 1/6] KVM: x86: hyper-v: Use common code for hypercall userspace exit

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Message-ID: <87edtvou0n.fsf@ovpn-194-185.brq.redhat.com>
Date:   Tue, 22 Nov 2022 17:04:24 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Vipin Sharma <vipinsh@...gle.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        seanjc@...gle.com, pbonzini@...hat.com, dmatlack@...gle.com
Subject: Re: [PATCH v2 1/6] KVM: x86: hyper-v: Use common code for hypercall
 userspace exit

Vipin Sharma <vipinsh@...gle.com> writes:

> Remove duplicate code to exit to userspace for hyper-v hypercalls and
> use a common place to exit.
>

"No functional change intended." as it was suggested by Sean :-)

> Signed-off-by: Vipin Sharma <vipinsh@...gle.com>
> Suggested-by: Sean Christopherson <seanjc@...gle.com>
> ---
>  arch/x86/kvm/hyperv.c | 27 +++++++++++----------------
>  1 file changed, 11 insertions(+), 16 deletions(-)
>
> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> index 2c7f2a26421e..0b6964ed2e66 100644
> --- a/arch/x86/kvm/hyperv.c
> +++ b/arch/x86/kvm/hyperv.c
> @@ -2503,14 +2503,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
>  			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
>  			break;
>  		}
> -		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
> -		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
> -		vcpu->run->hyperv.u.hcall.input = hc.param;
> -		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
> -		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
> -		vcpu->arch.complete_userspace_io =
> -				kvm_hv_hypercall_complete_userspace;
> -		return 0;
> +		goto hypercall_userspace_exit;
>  	case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
>  		if (unlikely(hc.var_cnt)) {
>  			ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
> @@ -2569,14 +2562,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
>  			ret = HV_STATUS_OPERATION_DENIED;
>  			break;
>  		}
> -		vcpu->run->exit_reason = KVM_EXIT_HYPERV;
> -		vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
> -		vcpu->run->hyperv.u.hcall.input = hc.param;
> -		vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
> -		vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
> -		vcpu->arch.complete_userspace_io =
> -				kvm_hv_hypercall_complete_userspace;
> -		return 0;
> +		goto hypercall_userspace_exit;
>  	}
>  	default:
>  		ret = HV_STATUS_INVALID_HYPERCALL_CODE;
> @@ -2585,6 +2571,15 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
>  
>  hypercall_complete:
>  	return kvm_hv_hypercall_complete(vcpu, ret);
> +
> +hypercall_userspace_exit:
> +	vcpu->run->exit_reason = KVM_EXIT_HYPERV;
> +	vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
> +	vcpu->run->hyperv.u.hcall.input = hc.param;
> +	vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
> +	vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
> +	vcpu->arch.complete_userspace_io = kvm_hv_hypercall_complete_userspace;
> +	return 0;
>  }
>  
>  void kvm_hv_init_vm(struct kvm *kvm)

Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>

-- 
Vitaly