Re: [RFC PATCH v5 39/52] i386/xen: add monitor commands to test event injection

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* David Woodhouse (dwmw2@infradead.org) wrote:
> From: Joao Martins <joao.m.martins@oracle.com>
> 
> Specifically add listing, injection of event channels.

These are all for debug only aren't they?

Even so, see docs/devel/writing-monitor-commands.rst, people like
commands to be built around qmp if possible now; there's a thing for
dumping text through it anyway for debug.


> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
> ---
>  hmp-commands.hx          | 29 ++++++++++++++
>  hw/i386/kvm/xen_evtchn.c | 83 ++++++++++++++++++++++++++++++++++++++++
>  hw/i386/kvm/xen_evtchn.h |  3 ++
>  monitor/misc.c           |  4 ++
>  4 files changed, 119 insertions(+)
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 673e39a697..fd77c432c0 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1815,3 +1815,32 @@ SRST
>    Dump the FDT in dtb format to *filename*.
>  ERST
>  #endif
> +
> +#if defined(CONFIG_XEN_EMU)
> +    {
> +        .name       = "xen-event-inject",
> +        .args_type  = "port:i",
> +        .params     = "port",
> +        .help       = "inject event channel",
> +        .cmd        = hmp_xen_event_inject,
> +    },
> +
> +SRST
> +``xen-event-inject`` *port*
> +  Notify guest via event channel on port *port*.
> +ERST
> +
> +
> +    {
> +        .name       = "xen-event-list",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "list event channel state",
> +        .cmd        = hmp_xen_event_list,
> +    },
> +
> +SRST
> +``xen-event-list``
> +  List event channels in the guest
> +ERST
> +#endif
> diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c
> index cdf7d86da8..87136334f5 100644
> --- a/hw/i386/kvm/xen_evtchn.c
> +++ b/hw/i386/kvm/xen_evtchn.c
> @@ -19,6 +19,8 @@
>  #include "exec/target_page.h"
>  #include "exec/address-spaces.h"
>  #include "migration/vmstate.h"
> +#include "monitor/monitor.h"
> +#include "qapi/qmp/qdict.h"
>  
>  #include "hw/sysbus.h"
>  #include "hw/xen/xen.h"
> @@ -1061,3 +1063,84 @@ int xen_evtchn_send_op(struct evtchn_send *send)
>      return ret;
>  }
>  
> +static const char *type_names[] = {
> +    "closed",
> +    "unbound",
> +    "interdomain",
> +    "pirq",
> +    "virq",
> +    "ipi"
> +};
> +
> +void hmp_xen_event_list(Monitor *mon, const QDict *qdict)
> +{
> +    XenEvtchnState *s = xen_evtchn_singleton;
> +    void *shinfo, *pending, *mask;
> +    int i;
> +
> +    if (!s) {
> +        monitor_printf(mon, "Xen event channel emulation not enabled\n");
> +        return;
> +    }
> +
> +    shinfo = xen_overlay_get_shinfo_ptr();
> +    if (!shinfo) {
> +        monitor_printf(mon, "Xen shared info page not allocated\n");
> +        return;
> +    }
> +    if (xen_is_long_mode()) {
> +        pending = shinfo + offsetof(struct shared_info, evtchn_pending);
> +        mask = shinfo + offsetof(struct shared_info, evtchn_mask);
> +    } else {
> +        pending = shinfo + offsetof(struct compat_shared_info, evtchn_pending);
> +        mask = shinfo + offsetof(struct compat_shared_info, evtchn_mask);
> +    }
> +
> +    qemu_mutex_lock(&s->port_lock);
> +
> +    for (i = 0; i < s->nr_ports; i++) {
> +        XenEvtchnPort *p = &s->port_table[i];
> +
> +        if (p->type == EVTCHNSTAT_closed) {
> +            continue;
> +        }
> +
> +        monitor_printf(mon, "port %4u %s/%d vcpu:%d pending:%d mask:%d\n", i,
> +                       type_names[p->type], p->type_val, p->vcpu,
> +                       test_bit(i, pending), test_bit(i, mask));
> +    }
> +
> +    qemu_mutex_unlock(&s->port_lock);
> +}
> +
> +void hmp_xen_event_inject(Monitor *mon, const QDict *qdict)
> +{
> +    XenEvtchnState *s = xen_evtchn_singleton;
> +    int port = qdict_get_int(qdict, "port");
> +    XenEvtchnPort *p;
> +
> +    if (!s) {
> +        monitor_printf(mon, "Xen event channel emulation not enabled\n");
> +        return;
> +    }
> +
> +    if (!valid_port(port)) {
> +        monitor_printf(mon, "Invalid port %d\n", port);
> +        return;
> +    }
> +    p = &s->port_table[port];
> +
> +    qemu_mutex_lock(&s->port_lock);
> +
> +    monitor_printf(mon, "port %4u %s/%d vcpu:%d\n", port,
> +                   type_names[p->type], p->type_val, p->vcpu);

Do you want a helper to check p->type before looking it up in the array?

Dave

> +
> +    if (set_port_pending(s, port)) {
> +        monitor_printf(mon, "Failed to set port %d\n", port);
> +    } else {
> +        monitor_printf(mon, "Delivered port %d\n", port);
> +    }
> +
> +    qemu_mutex_unlock(&s->port_lock);
> +}
> +
> diff --git a/hw/i386/kvm/xen_evtchn.h b/hw/i386/kvm/xen_evtchn.h
> index 5d3e03553f..1de53daa52 100644
> --- a/hw/i386/kvm/xen_evtchn.h
> +++ b/hw/i386/kvm/xen_evtchn.h
> @@ -16,6 +16,9 @@ void xen_evtchn_create(void);
>  int xen_evtchn_soft_reset(void);
>  int xen_evtchn_set_callback_param(uint64_t param);
>  
> +void hmp_xen_event_list(Monitor *mon, const QDict *qdict);
> +void hmp_xen_event_inject(Monitor *mon, const QDict *qdict);
> +
>  struct evtchn_status;
>  struct evtchn_close;
>  struct evtchn_unmask;
> diff --git a/monitor/misc.c b/monitor/misc.c
> index 205487e2b9..2b11c0f86a 100644
> --- a/monitor/misc.c
> +++ b/monitor/misc.c
> @@ -88,6 +88,10 @@
>  /* Make devices configuration available for use in hmp-commands*.hx templates */
>  #include CONFIG_DEVICES
>  
> +#ifdef CONFIG_XEN_EMU
> +#include "hw/i386/kvm/xen_evtchn.h"
> +#endif
> +
>  /* file descriptors passed via SCM_RIGHTS */
>  typedef struct mon_fd_t mon_fd_t;
>  struct mon_fd_t {
> -- 
> 2.35.3
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK