Re: [Qemu-devel] [PATCH v6 8/9] i386/kvm/pci-assign: Fix return type of verify_irqchip_kernel()

[Marcel Apfelbaum]

On 20/06/2017 14:57, Mao Zhongyi wrote:
> When the function no success value to transmit, it usually make the
> function return void. It has turned out not to be a success, because
> it means that the extra local_err variable and error_propagate() will
> be needed. It leads to cumbersome code, therefore, transmit success/
> failure in the return value is worth. So fix the return type to avoid
> it.
>
> Cc: address@hidden
> Cc: address@hidden
> Cc: address@hidden
> Cc: address@hidden
> Cc: address@hidden
> Cc: address@hidden
> Signed-off-by: Mao Zhongyi <address@hidden>
> ---
>   hw/i386/kvm/pci-assign.c | 18 ++++++------------
>   1 file changed, 6 insertions(+), 12 deletions(-)
>
> diff --git a/hw/i386/kvm/pci-assign.c b/hw/i386/kvm/pci-assign.c
> index 3d60455..b7fdb47 100644
> --- a/hw/i386/kvm/pci-assign.c
> +++ b/hw/i386/kvm/pci-assign.c
> @@ -824,12 +824,13 @@ static void assign_device(AssignedDevice *dev, Error 
> **errp)
>       }
>   }
>   
> -static void verify_irqchip_in_kernel(Error **errp)
> +static int verify_irqchip_in_kernel(Error **errp)
>   {
>       if (kvm_irqchip_in_kernel()) {
> -        return;
> +        return -1;
>       }
>       error_setg(errp, "pci-assign requires KVM with in-kernel irqchip 
> enabled");
> +    return 0;
>   }
>   
>   static int assign_intx(AssignedDevice *dev, Error **errp)
> @@ -838,7 +839,6 @@ static int assign_intx(AssignedDevice *dev, Error **errp)
>       PCIINTxRoute intx_route;
>       bool intx_host_msi;
>       int r;
> -    Error *local_err = NULL;
>   
>       /* Interrupt PIN 0 means don't use INTx */
>       if (assigned_dev_pci_read_byte(&dev->dev, PCI_INTERRUPT_PIN) == 0) {
> @@ -846,9 +846,7 @@ static int assign_intx(AssignedDevice *dev, Error **errp)
>           return 0;
>       }
>   
> -    verify_irqchip_in_kernel(&local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +    if (verify_irqchip_in_kernel(errp) < 0) {
>           return -ENOTSUP;
>       }
>   
> @@ -1246,9 +1244,7 @@ static int assigned_device_pci_cap_init(PCIDevice *pci_dev, Error **errp)
>        * MSI capability is the 1st capability in capability config */
>       pos = pci_find_cap_offset(pci_dev, PCI_CAP_ID_MSI, 0);
>       if (pos != 0 && kvm_check_extension(kvm_state, KVM_CAP_ASSIGN_DEV_IRQ)) {
> -        verify_irqchip_in_kernel(&local_err);
> -        if (local_err) {
> -            error_propagate(errp, local_err);
> +        if (verify_irqchip_in_kernel(errp) < 0) {
>               return -ENOTSUP;
>           }
>           dev->dev.cap_present |= QEMU_PCI_CAP_MSI;
> @@ -1281,9 +1277,7 @@ static int assigned_device_pci_cap_init(PCIDevice 
> *pci_dev, Error **errp)
>           uint32_t msix_table_entry;
>           uint16_t msix_max;
>   
> -        verify_irqchip_in_kernel(&local_err);
> -        if (local_err) {
> -            error_propagate(errp, local_err);
> +        if (verify_irqchip_in_kernel(errp) < 0) {
>               return -ENOTSUP;
>           }
>           dev->dev.cap_present |= QEMU_PCI_CAP_MSIX;

Reviewed-by: Marcel Apfelbaum <address@hidden>

Thanks,
Marcel