diff mbox series

[v3,1/5] virtio: add "use-started" property

Message ID 20190614093121.5580-2-xieyongji@baidu.com (mailing list archive)
State New, archived
Headers show
Series virtio: fix some issues of "started" and "start_on_kick" flag | expand

Commit Message

Yongji Xie June 14, 2019, 9:31 a.m. UTC 
From: Xie Yongji <xieyongji@baidu.com>

In order to avoid migration issues, we introduce a "use-started"
property to the base virtio device to indicate whether use
"started" flag or not. This property will be true by default and
set to false when machine type <= 4.0.1.

Suggested-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Xie Yongji <xieyongji@baidu.com>
---
 hw/block/vhost-user-blk.c  |  4 ++--
 hw/core/machine.c          |  8 ++++++--
 hw/virtio/virtio.c         | 18 +++++++-----------
 include/hw/virtio/virtio.h | 21 +++++++++++++++++++++
 4 files changed, 36 insertions(+), 15 deletions(-)

Comments

Greg Kurz June 14, 2019, 11:44 a.m. UTC | #1 
On Fri, 14 Jun 2019 17:31:17 +0800
elohimes@gmail.com wrote:

> From: Xie Yongji <xieyongji@baidu.com>
> 
> In order to avoid migration issues, we introduce a "use-started"
> property to the base virtio device to indicate whether use
> "started" flag or not. This property will be true by default and
> set to false when machine type <= 4.0.1.
> 
> Suggested-by: Greg Kurz <groug@kaod.org>
> Signed-off-by: Xie Yongji <xieyongji@baidu.com>
> ---
>  hw/block/vhost-user-blk.c  |  4 ++--
>  hw/core/machine.c          |  8 ++++++--

This patch conflicts with latest upstream changes to hw_compat_4_0_1[].

It seems you need to rebase. Also, I'm still not sure how we're supposed
to handle hw_compat_4_0_1[] versus hw_compat_4_0[]... nobody commented
on:

https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00637.html
https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00641.html

Maybe worth to sort that out before re-posting.

>  hw/virtio/virtio.c         | 18 +++++++-----------
>  include/hw/virtio/virtio.h | 21 +++++++++++++++++++++
>  4 files changed, 36 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> index 9cb61336a6..85bc4017e7 100644
> --- a/hw/block/vhost-user-blk.c
> +++ b/hw/block/vhost-user-blk.c
> @@ -191,7 +191,7 @@ static void vhost_user_blk_stop(VirtIODevice *vdev)
>  static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
>  {
>      VHostUserBlk *s = VHOST_USER_BLK(vdev);
> -    bool should_start = vdev->started;
> +    bool should_start = virtio_device_started(vdev, status);
>      int ret;
>  
>      if (!vdev->vm_running) {
> @@ -317,7 +317,7 @@ static int vhost_user_blk_connect(DeviceState *dev)
>      }
>  
>      /* restore vhost state */
> -    if (vdev->started) {
> +    if (virtio_device_started(vdev, vdev->status)) {
>          ret = vhost_user_blk_start(vdev);
>          if (ret < 0) {
>              error_report("vhost-user-blk: vhost start failed: %s",
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index f1a0f45f9c..60d1e27d2c 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -24,10 +24,14 @@
>  #include "hw/pci/pci.h"
>  #include "hw/mem/nvdimm.h"
>  
> -GlobalProperty hw_compat_4_0_1[] = {};
> +GlobalProperty hw_compat_4_0_1[] = {
> +    { "virtio-device", "use-started", "false" },
> +};
>  const size_t hw_compat_4_0_1_len = G_N_ELEMENTS(hw_compat_4_0_1);
>  
> -GlobalProperty hw_compat_4_0[] = {};
> +GlobalProperty hw_compat_4_0[] = {
> +    { "virtio-device", "use-started", "false" },
> +};
>  const size_t hw_compat_4_0_len = G_N_ELEMENTS(hw_compat_4_0);
>  
>  GlobalProperty hw_compat_3_1[] = {
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 07f4a64b48..19062fbb96 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -1162,10 +1162,8 @@ int virtio_set_status(VirtIODevice *vdev, uint8_t val)
>              }
>          }
>      }
> -    vdev->started = val & VIRTIO_CONFIG_S_DRIVER_OK;
> -    if (unlikely(vdev->start_on_kick && vdev->started)) {
> -        vdev->start_on_kick = false;
> -    }
> +
> +    virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK);
>  
>      if (k->set_status) {
>          k->set_status(vdev, val);
> @@ -1536,8 +1534,7 @@ static bool virtio_queue_notify_aio_vq(VirtQueue *vq)
>          ret = vq->handle_aio_output(vdev, vq);
>  
>          if (unlikely(vdev->start_on_kick)) {
> -            vdev->started = true;
> -            vdev->start_on_kick = false;
> +            virtio_set_started(vdev, true);
>          }
>      }
>  
> @@ -1557,8 +1554,7 @@ static void virtio_queue_notify_vq(VirtQueue *vq)
>          vq->handle_output(vdev, vq);
>  
>          if (unlikely(vdev->start_on_kick)) {
> -            vdev->started = true;
> -            vdev->start_on_kick = false;
> +            virtio_set_started(vdev, true);
>          }
>      }
>  }
> @@ -1579,8 +1575,7 @@ void virtio_queue_notify(VirtIODevice *vdev, int n)
>      }
>  
>      if (unlikely(vdev->start_on_kick)) {
> -        vdev->started = true;
> -        vdev->start_on_kick = false;
> +        virtio_set_started(vdev, true);
>      }
>  }
>  
> @@ -2291,7 +2286,7 @@ static void virtio_vmstate_change(void *opaque, int running, RunState state)
>      VirtIODevice *vdev = opaque;
>      BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
>      VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> -    bool backend_run = running && vdev->started;
> +    bool backend_run = running && virtio_device_started(vdev, vdev->status);
>      vdev->vm_running = running;
>  
>      if (backend_run) {
> @@ -2669,6 +2664,7 @@ static void virtio_device_instance_finalize(Object *obj)
>  
>  static Property virtio_properties[] = {
>      DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features),
> +    DEFINE_PROP_BOOL("use-started", VirtIODevice, use_started, true),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index 27c0efc3d0..15d5366939 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -105,6 +105,7 @@ struct VirtIODevice
>      uint16_t device_id;
>      bool vm_running;
>      bool broken; /* device in invalid state, needs reset */
> +    bool use_started;
>      bool started;
>      bool start_on_kick; /* virtio 1.0 transitional devices support that */
>      VMChangeStateEntry *vmstate;
> @@ -351,4 +352,24 @@ static inline bool virtio_is_big_endian(VirtIODevice *vdev)
>      /* Devices conforming to VIRTIO 1.0 or later are always LE. */
>      return false;
>  }
> +
> +static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
> +{
> +    if (vdev->use_started) {
> +        return vdev->started;
> +    }
> +
> +    return status & VIRTIO_CONFIG_S_DRIVER_OK;
> +}
> +
> +static inline void virtio_set_started(VirtIODevice *vdev, bool started)
> +{
> +    if (started) {
> +        vdev->start_on_kick = false;
> +    }
> +
> +    if (vdev->use_started) {
> +        vdev->started = started;
> +    }
> +}
>  #endif
Yongji Xie June 17, 2019, 2:14 a.m. UTC | #2 
On Fri, 14 Jun 2019 at 19:45, Greg Kurz <groug@kaod.org> wrote:
>
> On Fri, 14 Jun 2019 17:31:17 +0800
> elohimes@gmail.com wrote:
>
> > From: Xie Yongji <xieyongji@baidu.com>
> >
> > In order to avoid migration issues, we introduce a "use-started"
> > property to the base virtio device to indicate whether use
> > "started" flag or not. This property will be true by default and
> > set to false when machine type <= 4.0.1.
> >
> > Suggested-by: Greg Kurz <groug@kaod.org>
> > Signed-off-by: Xie Yongji <xieyongji@baidu.com>
> > ---
> >  hw/block/vhost-user-blk.c  |  4 ++--
> >  hw/core/machine.c          |  8 ++++++--
>
> This patch conflicts with latest upstream changes to hw_compat_4_0_1[].
>
> It seems you need to rebase. Also, I'm still not sure how we're supposed
> to handle hw_compat_4_0_1[] versus hw_compat_4_0[]... nobody commented
> on:
>
> https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00637.html
> https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00641.html
>
> Maybe worth to sort that out before re-posting.
>

If hw_compat_4_0_1[] is introduced only for q35, I think this patch
should be OK. If not, maybe we should handle hw_compat_4_0_1[] in
other machine types (i440fx, arm, ppc, s390)?

Hi Alex and Paolo,

Any comment for this?

Thanks,
Yongji
Greg Kurz June 17, 2019, 5:20 a.m. UTC | #3 
On Mon, 17 Jun 2019 10:14:30 +0800
Yongji Xie <elohimes@gmail.com> wrote:

> On Fri, 14 Jun 2019 at 19:45, Greg Kurz <groug@kaod.org> wrote:
> >
> > On Fri, 14 Jun 2019 17:31:17 +0800
> > elohimes@gmail.com wrote:
> >  
> > > From: Xie Yongji <xieyongji@baidu.com>
> > >
> > > In order to avoid migration issues, we introduce a "use-started"
> > > property to the base virtio device to indicate whether use
> > > "started" flag or not. This property will be true by default and
> > > set to false when machine type <= 4.0.1.
> > >
> > > Suggested-by: Greg Kurz <groug@kaod.org>
> > > Signed-off-by: Xie Yongji <xieyongji@baidu.com>
> > > ---
> > >  hw/block/vhost-user-blk.c  |  4 ++--
> > >  hw/core/machine.c          |  8 ++++++--  
> >
> > This patch conflicts with latest upstream changes to hw_compat_4_0_1[].
> >
> > It seems you need to rebase. Also, I'm still not sure how we're supposed
> > to handle hw_compat_4_0_1[] versus hw_compat_4_0[]... nobody commented
> > on:
> >
> > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00637.html
> > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00641.html
> >
> > Maybe worth to sort that out before re-posting.
> >  
> 
> If hw_compat_4_0_1[] is introduced only for q35, I think this patch
> should be OK. If not, maybe we should handle hw_compat_4_0_1[] in
> other machine types (i440fx, arm, ppc, s390)?
> 

It turns out that hw_compat_4_0_1[] isn't needed at all. Please see:

https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg03054.html

> Hi Alex and Paolo,
> 
> Any comment for this?
> 
> Thanks,
> Yongji
Yongji Xie June 17, 2019, 6:04 a.m. UTC | #4 
On Mon, 17 Jun 2019 at 13:24, Greg Kurz <groug@kaod.org> wrote:
>
> On Mon, 17 Jun 2019 10:14:30 +0800
> Yongji Xie <elohimes@gmail.com> wrote:
>
> > On Fri, 14 Jun 2019 at 19:45, Greg Kurz <groug@kaod.org> wrote:
> > >
> > > On Fri, 14 Jun 2019 17:31:17 +0800
> > > elohimes@gmail.com wrote:
> > >
> > > > From: Xie Yongji <xieyongji@baidu.com>
> > > >
> > > > In order to avoid migration issues, we introduce a "use-started"
> > > > property to the base virtio device to indicate whether use
> > > > "started" flag or not. This property will be true by default and
> > > > set to false when machine type <= 4.0.1.
> > > >
> > > > Suggested-by: Greg Kurz <groug@kaod.org>
> > > > Signed-off-by: Xie Yongji <xieyongji@baidu.com>
> > > > ---
> > > >  hw/block/vhost-user-blk.c  |  4 ++--
> > > >  hw/core/machine.c          |  8 ++++++--
> > >
> > > This patch conflicts with latest upstream changes to hw_compat_4_0_1[].
> > >
> > > It seems you need to rebase. Also, I'm still not sure how we're supposed
> > > to handle hw_compat_4_0_1[] versus hw_compat_4_0[]... nobody commented
> > > on:
> > >
> > > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00637.html
> > > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00641.html
> > >
> > > Maybe worth to sort that out before re-posting.
> > >
> >
> > If hw_compat_4_0_1[] is introduced only for q35, I think this patch
> > should be OK. If not, maybe we should handle hw_compat_4_0_1[] in
> > other machine types (i440fx, arm, ppc, s390)?
> >
>
> It turns out that hw_compat_4_0_1[] isn't needed at all. Please see:
>
> https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg03054.html
>

Oh, great! I will rebase my patch after this commit is merged.

Thanks,
Yongji
Greg Kurz June 22, 2019, 3:51 p.m. UTC | #5 
On Mon, 17 Jun 2019 14:04:10 +0800
Yongji Xie <elohimes@gmail.com> wrote:

> On Mon, 17 Jun 2019 at 13:24, Greg Kurz <groug@kaod.org> wrote:
> >
> > On Mon, 17 Jun 2019 10:14:30 +0800
> > Yongji Xie <elohimes@gmail.com> wrote:
> >  
> > > On Fri, 14 Jun 2019 at 19:45, Greg Kurz <groug@kaod.org> wrote:  
> > > >
> > > > On Fri, 14 Jun 2019 17:31:17 +0800
> > > > elohimes@gmail.com wrote:
> > > >  
> > > > > From: Xie Yongji <xieyongji@baidu.com>
> > > > >
> > > > > In order to avoid migration issues, we introduce a "use-started"
> > > > > property to the base virtio device to indicate whether use
> > > > > "started" flag or not. This property will be true by default and
> > > > > set to false when machine type <= 4.0.1.
> > > > >
> > > > > Suggested-by: Greg Kurz <groug@kaod.org>
> > > > > Signed-off-by: Xie Yongji <xieyongji@baidu.com>
> > > > > ---
> > > > >  hw/block/vhost-user-blk.c  |  4 ++--
> > > > >  hw/core/machine.c          |  8 ++++++--  
> > > >
> > > > This patch conflicts with latest upstream changes to hw_compat_4_0_1[].
> > > >
> > > > It seems you need to rebase. Also, I'm still not sure how we're supposed
> > > > to handle hw_compat_4_0_1[] versus hw_compat_4_0[]... nobody commented
> > > > on:
> > > >
> > > > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00637.html
> > > > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00641.html
> > > >
> > > > Maybe worth to sort that out before re-posting.
> > > >  
> > >
> > > If hw_compat_4_0_1[] is introduced only for q35, I think this patch
> > > should be OK. If not, maybe we should handle hw_compat_4_0_1[] in
> > > other machine types (i440fx, arm, ppc, s390)?
> > >  
> >
> > It turns out that hw_compat_4_0_1[] isn't needed at all. Please see:
> >
> > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg03054.html
> >  
> 
> Oh, great! I will rebase my patch after this commit is merged.
> 
> Thanks,
> Yongji

You can proceed.

https://git.qemu.org/?p=qemu.git;a=commit;h=8e8cbed09ad9d577955691b4c061b61b602406d1

Cheers,

--
Greg
Yongji Xie June 24, 2019, 9:44 a.m. UTC | #6 
On Sat, 22 Jun 2019 at 23:51, Greg Kurz <groug@kaod.org> wrote:
>
> On Mon, 17 Jun 2019 14:04:10 +0800
> Yongji Xie <elohimes@gmail.com> wrote:
>
> > On Mon, 17 Jun 2019 at 13:24, Greg Kurz <groug@kaod.org> wrote:
> > >
> > > On Mon, 17 Jun 2019 10:14:30 +0800
> > > Yongji Xie <elohimes@gmail.com> wrote:
> > >
> > > > On Fri, 14 Jun 2019 at 19:45, Greg Kurz <groug@kaod.org> wrote:
> > > > >
> > > > > On Fri, 14 Jun 2019 17:31:17 +0800
> > > > > elohimes@gmail.com wrote:
> > > > >
> > > > > > From: Xie Yongji <xieyongji@baidu.com>
> > > > > >
> > > > > > In order to avoid migration issues, we introduce a "use-started"
> > > > > > property to the base virtio device to indicate whether use
> > > > > > "started" flag or not. This property will be true by default and
> > > > > > set to false when machine type <= 4.0.1.
> > > > > >
> > > > > > Suggested-by: Greg Kurz <groug@kaod.org>
> > > > > > Signed-off-by: Xie Yongji <xieyongji@baidu.com>
> > > > > > ---
> > > > > >  hw/block/vhost-user-blk.c  |  4 ++--
> > > > > >  hw/core/machine.c          |  8 ++++++--
> > > > >
> > > > > This patch conflicts with latest upstream changes to hw_compat_4_0_1[].
> > > > >
> > > > > It seems you need to rebase. Also, I'm still not sure how we're supposed
> > > > > to handle hw_compat_4_0_1[] versus hw_compat_4_0[]... nobody commented
> > > > > on:
> > > > >
> > > > > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00637.html
> > > > > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg00641.html
> > > > >
> > > > > Maybe worth to sort that out before re-posting.
> > > > >
> > > >
> > > > If hw_compat_4_0_1[] is introduced only for q35, I think this patch
> > > > should be OK. If not, maybe we should handle hw_compat_4_0_1[] in
> > > > other machine types (i440fx, arm, ppc, s390)?
> > > >
> > >
> > > It turns out that hw_compat_4_0_1[] isn't needed at all. Please see:
> > >
> > > https://lists.gnu.org/archive/html/qemu-devel/2019-06/msg03054.html
> > >
> >
> > Oh, great! I will rebase my patch after this commit is merged.
> >
> > Thanks,
> > Yongji
>
> You can proceed.
>
> https://git.qemu.org/?p=qemu.git;a=commit;h=8e8cbed09ad9d577955691b4c061b61b602406d1
>

OK, Thank you.

Thanks,
Yongji
diff mbox series

Patch

diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 9cb61336a6..85bc4017e7 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -191,7 +191,7 @@  static void vhost_user_blk_stop(VirtIODevice *vdev)
 static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status)
 {
     VHostUserBlk *s = VHOST_USER_BLK(vdev);
-    bool should_start = vdev->started;
+    bool should_start = virtio_device_started(vdev, status);
     int ret;
 
     if (!vdev->vm_running) {
@@ -317,7 +317,7 @@  static int vhost_user_blk_connect(DeviceState *dev)
     }
 
     /* restore vhost state */
-    if (vdev->started) {
+    if (virtio_device_started(vdev, vdev->status)) {
         ret = vhost_user_blk_start(vdev);
         if (ret < 0) {
             error_report("vhost-user-blk: vhost start failed: %s",
diff --git a/hw/core/machine.c b/hw/core/machine.c
index f1a0f45f9c..60d1e27d2c 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -24,10 +24,14 @@ 
 #include "hw/pci/pci.h"
 #include "hw/mem/nvdimm.h"
 
-GlobalProperty hw_compat_4_0_1[] = {};
+GlobalProperty hw_compat_4_0_1[] = {
+    { "virtio-device", "use-started", "false" },
+};
 const size_t hw_compat_4_0_1_len = G_N_ELEMENTS(hw_compat_4_0_1);
 
-GlobalProperty hw_compat_4_0[] = {};
+GlobalProperty hw_compat_4_0[] = {
+    { "virtio-device", "use-started", "false" },
+};
 const size_t hw_compat_4_0_len = G_N_ELEMENTS(hw_compat_4_0);
 
 GlobalProperty hw_compat_3_1[] = {
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 07f4a64b48..19062fbb96 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1162,10 +1162,8 @@  int virtio_set_status(VirtIODevice *vdev, uint8_t val)
             }
         }
     }
-    vdev->started = val & VIRTIO_CONFIG_S_DRIVER_OK;
-    if (unlikely(vdev->start_on_kick && vdev->started)) {
-        vdev->start_on_kick = false;
-    }
+
+    virtio_set_started(vdev, val & VIRTIO_CONFIG_S_DRIVER_OK);
 
     if (k->set_status) {
         k->set_status(vdev, val);
@@ -1536,8 +1534,7 @@  static bool virtio_queue_notify_aio_vq(VirtQueue *vq)
         ret = vq->handle_aio_output(vdev, vq);
 
         if (unlikely(vdev->start_on_kick)) {
-            vdev->started = true;
-            vdev->start_on_kick = false;
+            virtio_set_started(vdev, true);
         }
     }
 
@@ -1557,8 +1554,7 @@  static void virtio_queue_notify_vq(VirtQueue *vq)
         vq->handle_output(vdev, vq);
 
         if (unlikely(vdev->start_on_kick)) {
-            vdev->started = true;
-            vdev->start_on_kick = false;
+            virtio_set_started(vdev, true);
         }
     }
 }
@@ -1579,8 +1575,7 @@  void virtio_queue_notify(VirtIODevice *vdev, int n)
     }
 
     if (unlikely(vdev->start_on_kick)) {
-        vdev->started = true;
-        vdev->start_on_kick = false;
+        virtio_set_started(vdev, true);
     }
 }
 
@@ -2291,7 +2286,7 @@  static void virtio_vmstate_change(void *opaque, int running, RunState state)
     VirtIODevice *vdev = opaque;
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    bool backend_run = running && vdev->started;
+    bool backend_run = running && virtio_device_started(vdev, vdev->status);
     vdev->vm_running = running;
 
     if (backend_run) {
@@ -2669,6 +2664,7 @@  static void virtio_device_instance_finalize(Object *obj)
 
 static Property virtio_properties[] = {
     DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features),
+    DEFINE_PROP_BOOL("use-started", VirtIODevice, use_started, true),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 27c0efc3d0..15d5366939 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -105,6 +105,7 @@  struct VirtIODevice
     uint16_t device_id;
     bool vm_running;
     bool broken; /* device in invalid state, needs reset */
+    bool use_started;
     bool started;
     bool start_on_kick; /* virtio 1.0 transitional devices support that */
     VMChangeStateEntry *vmstate;
@@ -351,4 +352,24 @@  static inline bool virtio_is_big_endian(VirtIODevice *vdev)
     /* Devices conforming to VIRTIO 1.0 or later are always LE. */
     return false;
 }
+
+static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status)
+{
+    if (vdev->use_started) {
+        return vdev->started;
+    }
+
+    return status & VIRTIO_CONFIG_S_DRIVER_OK;
+}
+
+static inline void virtio_set_started(VirtIODevice *vdev, bool started)
+{
+    if (started) {
+        vdev->start_on_kick = false;
+    }
+
+    if (vdev->use_started) {
+        vdev->started = started;
+    }
+}
 #endif