Re: [Qemu-devel] [PATCH v2 17/18] s390x/kvm: cache the kvm flic in a central function

[Christian Borntraeger]

On 01/17/2018 06:40 PM, David Hildenbrand wrote:
> This avoids tons of conversions when handling interrupts.
> 
> Signed-off-by: David Hildenbrand <address@hidden>

Acked-by: Christian Borntraeger <address@hidden>


> ---
>  hw/intc/s390_flic_kvm.c | 21 ++++++++++++++++-----
>  1 file changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/intc/s390_flic_kvm.c b/hw/intc/s390_flic_kvm.c
> index d277ffdd2e..3f804ad52e 100644
> --- a/hw/intc/s390_flic_kvm.c
> +++ b/hw/intc/s390_flic_kvm.c
> @@ -35,6 +35,17 @@ typedef struct KVMS390FLICState {
>      bool clear_io_supported;
>  } KVMS390FLICState;
> 
> +static KVMS390FLICState *s390_get_kvm_flic(S390FLICState *fs)
> +{
> +    static KVMS390FLICState *flic;
> +
> +    if (!flic) {
> +        /* we only have one flic device, so this is fine to cache */
> +        flic = KVM_S390_FLIC(fs);
> +    }
> +    return flic;
> +}
> +
>  /**
>   * flic_get_all_irqs - store all pending irqs in buffer
>   * @buf: pointer to buffer which is passed to kernel
> @@ -117,7 +128,7 @@ static void kvm_s390_inject_flic(S390FLICState *fs, 
> struct kvm_s390_irq *irq)
>      int r;
> 
>      if (use_flic) {
> -        r = flic_enqueue_irqs(irq, sizeof(*irq), KVM_S390_FLIC(fs));
> +        r = flic_enqueue_irqs(irq, sizeof(*irq), s390_get_kvm_flic(fs));
>          if (r == -ENOSYS) {
>              use_flic = false;
>          }
> @@ -174,7 +185,7 @@ static void kvm_s390_inject_crw_mchk(S390FLICState *fs)
>  static int kvm_s390_clear_io_flic(S390FLICState *fs, uint16_t subchannel_id,
>                             uint16_t subchannel_nr)
>  {
> -    KVMS390FLICState *flic = KVM_S390_FLIC(fs);
> +    KVMS390FLICState *flic = s390_get_kvm_flic(fs);
>      int rc;
>      uint32_t sid = subchannel_id << 16 | subchannel_nr;
>      struct kvm_device_attr attr = {
> @@ -192,7 +203,7 @@ static int kvm_s390_clear_io_flic(S390FLICState *fs, 
> uint16_t subchannel_id,
>  static int kvm_s390_modify_ais_mode(S390FLICState *fs, uint8_t isc,
>                                      uint16_t mode)
>  {
> -    KVMS390FLICState *flic = KVM_S390_FLIC(fs);
> +    KVMS390FLICState *flic = s390_get_kvm_flic(fs);
>      struct kvm_s390_ais_req req = {
>          .isc = isc,
>          .mode = mode,
> @@ -212,7 +223,7 @@ static int kvm_s390_modify_ais_mode(S390FLICState *fs, 
> uint8_t isc,
>  static int kvm_s390_inject_airq(S390FLICState *fs, uint8_t type,
>                                  uint8_t isc, uint8_t flags)
>  {
> -    KVMS390FLICState *flic = KVM_S390_FLIC(fs);
> +    KVMS390FLICState *flic = s390_get_kvm_flic(fs);
>      uint32_t id = css_get_adapter_id(type, isc);
>      struct kvm_device_attr attr = {
>          .group = KVM_DEV_FLIC_AIRQ_INJECT,
> @@ -301,7 +312,7 @@ static int kvm_s390_io_adapter_map(S390FLICState *fs, 
> uint32_t id,
>          .group = KVM_DEV_FLIC_ADAPTER_MODIFY,
>          .addr = (uint64_t)&req,
>      };
> -    KVMS390FLICState *flic = KVM_S390_FLIC(fs);
> +    KVMS390FLICState *flic = s390_get_kvm_flic(fs);
>      int r;
> 
>      if (!kvm_gsi_routing_enabled()) {
>