On Thu, 14 Feb 2019 14:51:07 +0100
Pierre Morel <pmo...@linux.ibm.com> wrote:

> We register the AP PQAP instruction hook during the open
> of the mediated device. And unregister it on release.
> 
> In the AP PQAP instruction hook, if we receive a demand to
> enable IRQs,
> - we retrieve the vfio_ap_queue based on the APQN we receive
>   in REG1,
> - we retrieve the page of the guest address, (NIB), from
>   register REG2
> - we the mediated device to use the VFIO pinning infratrsucture
>   to pin the page of the guest address,
> - we retrieve the pointer to KVM to register the guest ISC
>   and retrieve the host ISC
> - finaly we activate GISA
> 
> If we receive a demand to disable IRQs,
> - we deactivate GISA
> - unregister from the GIB
> - unping the NIB
> 
> Signed-off-by: Pierre Morel <pmo...@linux.ibm.com>
> ---

[..]

> +static int handle_pqap(struct kvm_vcpu *vcpu)
> +{
> +     uint64_t status;
> +     uint16_t apqn;
> +     struct vfio_ap_queue *q;
> +     struct ap_queue_status qstatus = {};
> +     struct ap_matrix_mdev *matrix_mdev;
> +
> +     /* If we do not use the AIV facility just go to userland */
> +     if (!(vcpu->arch.sie_block->eca & ECA_AIV))
> +             return -EOPNOTSUPP;
> +
> +     apqn = vcpu->run->s.regs.gprs[0] & 0xffff;
> +     q = vfio_ap_get_queue(apqn);
> +     if (!q) {
> +             qstatus.response_code = AP_RESPONSE_Q_NOT_AVAIL;
> +             goto out;
> +     }
> +
> +     /* Check if the queue is associated with a guest matrix */
> +     matrix_mdev = q->matrix;
> +     if (!matrix_mdev || !matrix_mdev->kvm) {
> +             qstatus.response_code = AP_RESPONSE_DECONFIGURED;
> +             goto out;
> +     }
> +
> +     status = vcpu->run->s.regs.gprs[1];
> +
> +     /* If IR bit(16) is set we enable the interrupt */
> +     if ((status >> (63 - 16)) & 0x01) {
> +             q->isc = status & 0x07;
> +             q->nib = vcpu->run->s.regs.gprs[2];

Careful! You may already have q->nib set (may or may not be a 0x07
scenario). You should unpin the old nib if set interruption controls
works out, if we get 0x07 response then you unpin the new one.


> +             qstatus = vfio_ap_setirq(q);
> +             if (qstatus.response_code) {
> +                     q->nib = 0;
> +                     q->isc = 0;
> +             }
> +     } else
> +             qstatus = vfio_ap_clrirq(q);
> +
> +out:
> +     memcpy(&vcpu->run->s.regs.gprs[1], &qstatus, sizeof(qstatus));
> +     vfio_ap_put_queue(q);
> +     return 0;
> +}

[..]

>  
> @@ -877,11 +1052,15 @@ static int vfio_ap_mdev_reset_queue(unsigned int apid, 
> unsigned int apqi,
>                                   unsigned int retry)
>  {
>       struct ap_queue_status status;
> +     struct vfio_ap_queue *q;
> +
> +     q = vfio_ap_get_queue(AP_MKQID(apid, apqi));
>  
>       do {
>               status = ap_zapq(AP_MKQID(apid, apqi));
>               switch (status.response_code) {
>               case AP_RESPONSE_NORMAL:

You could do the get queue here

> +                     vfio_ap_free_irq(q);

And the put here.


Regards,
Halil

>                       return 0;
>               case AP_RESPONSE_RESET_IN_PROGRESS:
>               case AP_RESPONSE_BUSY:
> @@ -999,6 +1178,11 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev)
>       if (ret)
>               goto err_group;
>  
> +     if (!matrix_mdev->kvm) {
> +             ret = -ENODEV;
> +             goto err_iommu;
> +     }
> +
>       matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier;
>       events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
>  

[..]

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