Re: [PATCH 01/12] KVM: s390: reverse bit ordering of irqs in pending mask

Cornelia Huck
2018-01-18T16:50:04Z

On Tue, 16 Jan 2018 21:02:06 +0100
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> From: Michael Mueller <mimu@linux.vnet.ibm.com>
>
> This patch prepares a simplification of bit operations between the irq
> pending mask for emulated interrupts and the Interruption Pending Mask
> (IPM) which is part of the Guest Interruption State Area (GISA), a feature
> that allows interrupt delivery to guests by means of the SIE instruction.
>
> Without that change, a bit-wise *or* operation on parts of these two masks
> would either require a look-up table of size 256 bytes to map the IPM
> to the emulated irq pending mask bit orientation (all bits mirrored at half
> byte) or a sequence of up to 8 condidional branches to perform tests of
> single bit positions. Both options are to reject either by performance or

s/to reject/to be rejected/

> space utilization reasons.
>
> Beyond that this change will be transparent.
>
> Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com>
> Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>
> Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
> arch/s390/include/asm/kvm_host.h | 54 ++++++++++++++++++++--------------------
> arch/s390/kvm/interrupt.c | 10 ++++----
> 2 files changed, 32 insertions(+), 32 deletions(-)
>
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index e16a9f2a44ad..9981721f258f 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -409,35 +409,35 @@ struct kvm_vcpu_stat {
> #define PGM_PER 0x80
> #define PGM_CRYPTO_OPERATION 0x119
>
> -/* irq types in order of priority */
> +/* irq types in ascend order of priorities */

"ascending order of priority"?

Otherwise (and with the "reversed order" change),

Reviewed-by: Cornelia Huck <cohuck@redhat.com>