Re: [PATCH v2 1/4] hyperv: SControl is optional to enable SynIc

[Jon Doron <arilou@gmail.com>]

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Thanks! is there an estimate when will this patchset be merged?

On Thu, Feb 24, 2022, 18:36 Emanuele Giuseppe Esposito <eesposit@redhat.com>
wrote:

>
>
> On 16/02/2022 11:24, Jon Doron wrote:
> > SynIc can be enabled regardless of the SControl mechanisim which can
> > register a GSI for a given SintRoute.
> >
> > This behaviour can achived by setting enabling SIMP and then the guest
> > will poll on the message slot.
> >
> > Once there is another message pending the host will set the message slot
> > with the pending flag.
> > When the guest polls from the message slot, in case the pending flag is
> > set it will write to the HV_X64_MSR_EOM indicating it has cleared the
> > slot and we can try and push our message again.
> >
> > Signed-off-by: Jon Doron <arilou@gmail.com>
> > ---
> >  hw/hyperv/hyperv.c | 109 +++++++++++++++++++++++++++++++--------------
> >  1 file changed, 76 insertions(+), 33 deletions(-)
> >
> > diff --git a/hw/hyperv/hyperv.c b/hw/hyperv/hyperv.c
> > index cb1074f234..aaba6b4901 100644
> > --- a/hw/hyperv/hyperv.c
> > +++ b/hw/hyperv/hyperv.c
> > @@ -27,13 +27,16 @@ struct SynICState {
> >
> >      CPUState *cs;
> >
> > -    bool enabled;
> > +    bool sctl_enabled;
> >      hwaddr msg_page_addr;
> >      hwaddr event_page_addr;
> >      MemoryRegion msg_page_mr;
> >      MemoryRegion event_page_mr;
> >      struct hyperv_message_page *msg_page;
> >      struct hyperv_event_flags_page *event_page;
> > +
> > +    QemuMutex sint_routes_mutex;
> > +    QLIST_HEAD(, HvSintRoute) sint_routes;
> >  };
> >
> >  #define TYPE_SYNIC "hyperv-synic"
> > @@ -51,11 +54,11 @@ static SynICState *get_synic(CPUState *cs)
> >      return SYNIC(object_resolve_path_component(OBJECT(cs), "synic"));
> >  }
> >
> > -static void synic_update(SynICState *synic, bool enable,
> > +static void synic_update(SynICState *synic, bool sctl_enable,
> >                           hwaddr msg_page_addr, hwaddr event_page_addr)
> >  {
> >
> > -    synic->enabled = enable;
> > +    synic->sctl_enabled = sctl_enable;
> >      if (synic->msg_page_addr != msg_page_addr) {
> >          if (synic->msg_page_addr) {
> >              memory_region_del_subregion(get_system_memory(),
> > @@ -80,7 +83,7 @@ static void synic_update(SynICState *synic, bool
> enable,
> >      }
> >  }
> >
> > -void hyperv_synic_update(CPUState *cs, bool enable,
> > +void hyperv_synic_update(CPUState *cs, bool sctl_enable,
> >                           hwaddr msg_page_addr, hwaddr event_page_addr)
> >  {
> >      SynICState *synic = get_synic(cs);
> > @@ -89,7 +92,7 @@ void hyperv_synic_update(CPUState *cs, bool enable,
> >          return;
> >      }
> >
> > -    synic_update(synic, enable, msg_page_addr, event_page_addr);
> > +    synic_update(synic, sctl_enable, msg_page_addr, event_page_addr);
> >  }
> >
> >  static void synic_realize(DeviceState *dev, Error **errp)
> > @@ -110,16 +113,20 @@ static void synic_realize(DeviceState *dev, Error
> **errp)
> >                             sizeof(*synic->event_page), &error_abort);
> >      synic->msg_page = memory_region_get_ram_ptr(&synic->msg_page_mr);
> >      synic->event_page =
> memory_region_get_ram_ptr(&synic->event_page_mr);
> > +    qemu_mutex_init(&synic->sint_routes_mutex);
> > +    QLIST_INIT(&synic->sint_routes);
> >
> >      g_free(msgp_name);
> >      g_free(eventp_name);
> >  }
> > +
> >  static void synic_reset(DeviceState *dev)
> >  {
> >      SynICState *synic = SYNIC(dev);
> >      memset(synic->msg_page, 0, sizeof(*synic->msg_page));
> >      memset(synic->event_page, 0, sizeof(*synic->event_page));
> >      synic_update(synic, false, 0, 0);
> > +    assert(QLIST_EMPTY(&synic->sint_routes));
> >  }
> >
> >  static void synic_class_init(ObjectClass *klass, void *data)
> > @@ -214,6 +221,7 @@ struct HvSintRoute {
> >      HvSintStagedMessage *staged_msg;
> >
> >      unsigned refcount;
> > +    QLIST_ENTRY(HvSintRoute) link;
> >  };
> >
> >  static CPUState *hyperv_find_vcpu(uint32_t vp_index)
> > @@ -259,7 +267,7 @@ static void cpu_post_msg(CPUState *cs,
> run_on_cpu_data data)
> >
> >      assert(staged_msg->state == HV_STAGED_MSG_BUSY);
> >
> > -    if (!synic->enabled || !synic->msg_page_addr) {
> > +    if (!synic->msg_page_addr) {
> >          staged_msg->status = -ENXIO;
> >          goto posted;
> >      }
> > @@ -343,7 +351,7 @@ int hyperv_set_event_flag(HvSintRoute *sint_route,
> unsigned eventno)
> >      if (eventno > HV_EVENT_FLAGS_COUNT) {
> >          return -EINVAL;
> >      }
> > -    if (!synic->enabled || !synic->event_page_addr) {
> > +    if (!synic->sctl_enabled || !synic->event_page_addr) {
> >          return -ENXIO;
> >      }
> >
> > @@ -364,11 +372,12 @@ int hyperv_set_event_flag(HvSintRoute *sint_route,
> unsigned eventno)
> >  HvSintRoute *hyperv_sint_route_new(uint32_t vp_index, uint32_t sint,
> >                                     HvSintMsgCb cb, void *cb_data)
> >  {
> > -    HvSintRoute *sint_route;
> > -    EventNotifier *ack_notifier;
> > +    HvSintRoute *sint_route = NULL;
> > +    EventNotifier *ack_notifier = NULL;
> >      int r, gsi;
> >      CPUState *cs;
> >      SynICState *synic;
> > +    bool ack_event_initialized = false;
> >
> >      cs = hyperv_find_vcpu(vp_index);
> >      if (!cs) {
> > @@ -381,57 +390,77 @@ HvSintRoute *hyperv_sint_route_new(uint32_t
> vp_index, uint32_t sint,
> >      }
> >
> >      sint_route = g_new0(HvSintRoute, 1);
> > -    r = event_notifier_init(&sint_route->sint_set_notifier, false);
> > -    if (r) {
> > -        goto err;
> > +    if (!sint_route) {
> > +        return NULL;
> >      }
> >
> > +    sint_route->synic = synic;
> > +    sint_route->sint = sint;
> > +    sint_route->refcount = 1;
> >
> >      ack_notifier = cb ? &sint_route->sint_ack_notifier : NULL;
> >      if (ack_notifier) {
> >          sint_route->staged_msg = g_new0(HvSintStagedMessage, 1);
> > +        if (!sint_route->staged_msg) {
> > +            goto cleanup_err_sint;
> > +        }
> >          sint_route->staged_msg->cb = cb;
> >          sint_route->staged_msg->cb_data = cb_data;
> >
> >          r = event_notifier_init(ack_notifier, false);
> >          if (r) {
> > -            goto err_sint_set_notifier;
> > +            goto cleanup_err_sint;
> >          }
> > -
> >          event_notifier_set_handler(ack_notifier, sint_ack_handler);
> > +        ack_event_initialized = true;
> > +    }
> > +
> > +    /* See if we are done or we need to setup a GSI for this SintRoute
> */
> > +    if (!synic->sctl_enabled) {
> > +        goto cleanup;
> > +    }
> > +
> > +    /* We need to setup a GSI for this SintRoute */
> > +    r = event_notifier_init(&sint_route->sint_set_notifier, false);
> > +    if (r) {
> > +        goto cleanup_err_sint;
> >      }
> >
> >      gsi = kvm_irqchip_add_hv_sint_route(kvm_state, vp_index, sint);
> >      if (gsi < 0) {
> > -        goto err_gsi;
> > +        goto cleanup_err_sint_notifier;
> >      }
> >
> >      r = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state,
> >
>  &sint_route->sint_set_notifier,
> >                                             ack_notifier, gsi);
> >      if (r) {
> > -        goto err_irqfd;
> > +        goto cleanup_err_irqfd;
> >      }
> >      sint_route->gsi = gsi;
> > -    sint_route->synic = synic;
> > -    sint_route->sint = sint;
> > -    sint_route->refcount = 1;
> > -
> > +cleanup:
> > +    qemu_mutex_lock(&synic->sint_routes_mutex);
> > +    QLIST_INSERT_HEAD_RCU(&synic->sint_routes, sint_route, link);
> > +    qemu_mutex_unlock(&synic->sint_routes_mutex);
> >      return sint_route;
> >
> > -err_irqfd:
> > +cleanup_err_irqfd:
> >      kvm_irqchip_release_virq(kvm_state, gsi);
> > -err_gsi:
> > +
> > +cleanup_err_sint_notifier:
> > +    event_notifier_cleanup(&sint_route->sint_set_notifier);
> > +
> > +cleanup_err_sint:
> >      if (ack_notifier) {
> > -        event_notifier_set_handler(ack_notifier, NULL);
> > -        event_notifier_cleanup(ack_notifier);
> > +        if (ack_event_initialized) {
> > +            event_notifier_set_handler(ack_notifier, NULL);
> > +            event_notifier_cleanup(ack_notifier);
> > +        }
> > +
> >          g_free(sint_route->staged_msg);
> >      }
> > -err_sint_set_notifier:
> > -    event_notifier_cleanup(&sint_route->sint_set_notifier);
> > -err:
> > -    g_free(sint_route);
> >
> > +    g_free(sint_route);
> >      return NULL;
> >  }
> >
> > @@ -442,6 +471,8 @@ void hyperv_sint_route_ref(HvSintRoute *sint_route)
> >
> >  void hyperv_sint_route_unref(HvSintRoute *sint_route)
> >  {
> > +    SynICState *synic;
> > +
> >      if (!sint_route) {
> >          return;
> >      }
> > @@ -452,21 +483,33 @@ void hyperv_sint_route_unref(HvSintRoute
> *sint_route)
> >          return;
> >      }
> >
> > -    kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state,
> > -
> &sint_route->sint_set_notifier,
> > -                                          sint_route->gsi);
> > -    kvm_irqchip_release_virq(kvm_state, sint_route->gsi);
> > +    synic = sint_route->synic;
> > +    qemu_mutex_lock(&synic->sint_routes_mutex);
> > +    QLIST_REMOVE_RCU(sint_route, link);
> > +    qemu_mutex_unlock(&synic->sint_routes_mutex);
> > +
> > +    if (sint_route->gsi) {
> > +        kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state,
> > +
> &sint_route->sint_set_notifier,
> > +                                              sint_route->gsi);
> > +        kvm_irqchip_release_virq(kvm_state, sint_route->gsi);
> > +        event_notifier_cleanup(&sint_route->sint_set_notifier);
> > +    }
> > +
> >      if (sint_route->staged_msg) {
> >          event_notifier_set_handler(&sint_route->sint_ack_notifier,
> NULL);
> >          event_notifier_cleanup(&sint_route->sint_ack_notifier);
> >          g_free(sint_route->staged_msg);
> >      }
> > -    event_notifier_cleanup(&sint_route->sint_set_notifier);
> >      g_free(sint_route);
> >  }
> >
> >  int hyperv_sint_route_set_sint(HvSintRoute *sint_route)
> >  {
> > +    if (!sint_route->gsi) {
> > +        return 0;
> > +    }
> > +
> >      return event_notifier_set(&sint_route->sint_set_notifier);
> >  }
> >
> >
>
> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
>
>

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