Re: [PATCH v10 35/59] hw/xen: Implement EVTCHNOP_alloc_unbound

[Paul Durrant]

On 01/02/2023 14:31, David Woodhouse wrote:
> From: David Woodhouse <dwmw@amazon.co.uk>
>
> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
> ---
>   hw/i386/kvm/xen_evtchn.c  | 32 ++++++++++++++++++++++++++++++++
>   hw/i386/kvm/xen_evtchn.h  |  2 ++
>   target/i386/kvm/xen-emu.c | 15 +++++++++++++++
>   3 files changed, 49 insertions(+)
>
> diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c
> index a97d6ba61d..9dc5a98d94 100644
> --- a/hw/i386/kvm/xen_evtchn.c
> +++ b/hw/i386/kvm/xen_evtchn.c
> @@ -835,6 +835,38 @@ int xen_evtchn_bind_ipi_op(struct evtchn_bind_ipi *ipi)
>       return ret;
>   }
>   
> +int xen_evtchn_alloc_unbound_op(struct evtchn_alloc_unbound *alloc)
> +{
> +    XenEvtchnState *s = xen_evtchn_singleton;
> +    uint16_t type_val;
> +    int ret;
> +
> +    if (!s) {
> +        return -ENOTSUP;
> +    }
> +
> +    if (alloc->dom != DOMID_SELF && alloc->dom != xen_domid) {
> +        return -ESRCH;
> +    }
> +
> +    if (alloc->remote_dom == DOMID_QEMU) {
> +        type_val = PORT_INFO_TYPEVAL_REMOTE_QEMU;
> +    } else if (alloc->remote_dom == DOMID_SELF ||
> +               alloc->remote_dom == xen_domid) {
> +        type_val = 0;
> +    } else {
> +        return -EPERM;
> +    }
> +
> +    qemu_mutex_lock(&s->port_lock);
> +
> +    ret = allocate_port(s, 0, EVTCHNSTAT_unbound, type_val, &alloc->port);
> +
> +    qemu_mutex_unlock(&s->port_lock);
> +
> +    return ret;
> +}
> +
>   int xen_evtchn_send_op(struct evtchn_send *send)
>   {
>       XenEvtchnState *s = xen_evtchn_singleton;
> diff --git a/hw/i386/kvm/xen_evtchn.h b/hw/i386/kvm/xen_evtchn.h
> index 500fdbe8b8..fc080138e3 100644
> --- a/hw/i386/kvm/xen_evtchn.h
> +++ b/hw/i386/kvm/xen_evtchn.h
> @@ -21,11 +21,13 @@ struct evtchn_unmask;
>   struct evtchn_bind_virq;
>   struct evtchn_bind_ipi;
>   struct evtchn_send;
> +struct evtchn_alloc_unbound;
>   int xen_evtchn_status_op(struct evtchn_status *status);
>   int xen_evtchn_close_op(struct evtchn_close *close);
>   int xen_evtchn_unmask_op(struct evtchn_unmask *unmask);
>   int xen_evtchn_bind_virq_op(struct evtchn_bind_virq *virq);
>   int xen_evtchn_bind_ipi_op(struct evtchn_bind_ipi *ipi);
>   int xen_evtchn_send_op(struct evtchn_send *send);
> +int xen_evtchn_alloc_unbound_op(struct evtchn_alloc_unbound *alloc);
>   
>   #endif /* QEMU_XEN_EVTCHN_H */
> diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
> index 5299614d3c..e186dec9a9 100644
> --- a/target/i386/kvm/xen-emu.c
> +++ b/target/i386/kvm/xen-emu.c
> @@ -918,6 +918,21 @@ static bool kvm_xen_hcall_evtchn_op(struct kvm_xen_exit 
> *exit, X86CPU *cpu,
>           err = xen_evtchn_send_op(&send);
>           break;
>       }
> +    case EVTCHNOP_alloc_unbound: {
> +        struct evtchn_alloc_unbound alloc;
> +
> +        qemu_build_assert(sizeof(alloc) == 8);

Why?

  Paul

> +        if (kvm_copy_from_gva(cs, arg, &alloc, sizeof(alloc))) {
> +            err = -EFAULT;
> +            break;
> +        }
> +
> +        err = xen_evtchn_alloc_unbound_op(&alloc);
> +        if (!err && kvm_copy_to_gva(cs, arg, &alloc, sizeof(alloc))) {
> +            err = -EFAULT;
> +        }
> +        break;
> +    }
>       default:
>           return false;
>       }