Re: [Qemu-devel] [PATCH v1 for-2.12 1/5] s390x/kvm: factor out build_channel_report_mcic() into cpu.h

[Cornelia Huck <cohuck@redhat.com>]

On Mon,  4 Dec 2017 13:55:01 +0100
David Hildenbrand <david@redhat.com> wrote:

> We'll need it later on in two places. Refactor it to just indicate the
> valid bit. While at it, introduce a define for the used CR14 bit (we'll

s/valid bit/validity bits/

> also need later on).
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/cpu.h | 20 ++++++++++++++++++++
>  target/s390x/kvm.c | 25 ++-----------------------
>  2 files changed, 22 insertions(+), 23 deletions(-)
> 
> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
> index 9cfbbbac04..4d3e7920f5 100644
> --- a/target/s390x/cpu.h
> +++ b/target/s390x/cpu.h
> @@ -351,6 +351,9 @@ extern const struct VMStateDescription vmstate_s390_cpu;
>  #define CR0_CPU_TIMER_SC        0x0000000000000400ULL
>  #define CR0_SERVICE_SC          0x0000000000000200ULL
>  
> +/* Control register 14 bits */
> +#define CR14_CHANNEL_REPORT_SC  0x0000000010000000ULL
> +
>  /* MMU */
>  #define MMU_PRIMARY_IDX         0
>  #define MMU_SECONDARY_IDX       1
> @@ -674,6 +677,23 @@ struct sysib_322 {
>  #define MCIC_VB_CT 0x0000000000020000ULL
>  #define MCIC_VB_CC 0x0000000000010000ULL
>  
> +static inline uint64_t s390_build_validity_mcic(void)
> +{
> +    uint64_t mcic;
> +
> +    /* indicate all valid bits (no damage) */

s/valid/validity/

> +    mcic = MCIC_VB_WP | MCIC_VB_MS | MCIC_VB_PM | MCIC_VB_IA | MCIC_VB_FP |
> +           MCIC_VB_GR | MCIC_VB_CR | MCIC_VB_ST | MCIC_VB_AR | MCIC_VB_PR |
> +           MCIC_VB_FC | MCIC_VB_CT | MCIC_VB_CC;
> +    if (s390_has_feat(S390_FEAT_VECTOR)) {
> +        mcic |= MCIC_VB_VR;
> +    }
> +    if (s390_has_feat(S390_FEAT_GUARDED_STORAGE)) {
> +        mcic |= MCIC_VB_GS;
> +    }
> +    return mcic;
> +}
> +

Not sure why this should go into cpu.h - isn't there a better header
for it?

>  
>  /* cpu.c */
>  int s390_get_clock(uint8_t *tod_high, uint64_t *tod_low);
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index 97c45d5537..9b8b59f2a2 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -1852,33 +1852,12 @@ void kvm_s390_io_interrupt(uint16_t subchannel_id,
>      kvm_s390_floating_interrupt(&irq);
>  }
>  
> -static uint64_t build_channel_report_mcic(void)
> -{
> -    uint64_t mcic;
> -
> -    /* subclass: indicate channel report pending */
> -    mcic = MCIC_SC_CP |
> -    /* subclass modifiers: none */
> -    /* storage errors: none */

I find these additional comments quite useful - can they be preserved
in any way?

> -    /* validity bits: no damage */
> -        MCIC_VB_WP | MCIC_VB_MS | MCIC_VB_PM | MCIC_VB_IA | MCIC_VB_FP |
> -        MCIC_VB_GR | MCIC_VB_CR | MCIC_VB_ST | MCIC_VB_AR | MCIC_VB_PR |
> -        MCIC_VB_FC | MCIC_VB_CT | MCIC_VB_CC;
> -    if (s390_has_feat(S390_FEAT_VECTOR)) {
> -        mcic |= MCIC_VB_VR;
> -    }
> -    if (s390_has_feat(S390_FEAT_GUARDED_STORAGE)) {
> -        mcic |= MCIC_VB_GS;
> -    }
> -    return mcic;
> -}
> -
>  void kvm_s390_crw_mchk(void)
>  {
>      struct kvm_s390_irq irq = {
>          .type = KVM_S390_MCHK,
> -        .u.mchk.cr14 = 1 << 28,
> -        .u.mchk.mcic = build_channel_report_mcic(),
> +        .u.mchk.cr14 = CR14_CHANNEL_REPORT_SC,

I like this new define.

> +        .u.mchk.mcic = s390_build_validity_mcic() | MCIC_SC_CP,
>      };
>      kvm_s390_floating_interrupt(&irq);
>  }