xen: Fix xen-legacy-backend qdev types

[PATCH] xen: Fix xen-legacy-backend qdev types

Posted by Jason Andryuk 5 years, 4 months ago

xen-sysdev is a TYPE_SYS_BUS_DEVICE.  bus_type should not be changed so
that it can plug into the System bus.  Otherwise this assert triggers:
qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
`dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
failed.

TYPE_XENBACKEND attaches to TYPE_XENSYSBUS, so its class_init needs to
be set accordingly to attach the qdev.  Otherwise the following assert
triggers:
qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
`dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
failed.

TYPE_XENBACKEND is not a subclass of XEN_XENSYSDEV, so it's parent
is just TYPE_DEVICE.  Change that.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
---
 hw/xen/xen-legacy-backend.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c
index 2335ee2e65..c5c75c0064 100644
--- a/hw/xen/xen-legacy-backend.c
+++ b/hw/xen/xen-legacy-backend.c
@@ -789,11 +789,12 @@ static void xendev_class_init(ObjectClass *klass, void *data)
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
     /* xen-backend devices can be plugged/unplugged dynamically */
     dc->user_creatable = true;
+    dc->bus_type = TYPE_XENSYSBUS;
 }
 
 static const TypeInfo xendev_type_info = {
     .name          = TYPE_XENBACKEND,
-    .parent        = TYPE_XENSYSDEV,
+    .parent        = TYPE_DEVICE,
     .class_init    = xendev_class_init,
     .instance_size = sizeof(struct XenLegacyDevice),
 };
@@ -824,7 +825,6 @@ static void xen_sysdev_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     device_class_set_props(dc, xen_sysdev_properties);
-    dc->bus_type = TYPE_XENSYSBUS;
 }
 
 static const TypeInfo xensysdev_info = {
-- 
2.25.1

RE: [PATCH] xen: Fix xen-legacy-backend qdev types

Posted by Paul Durrant 5 years, 4 months ago

> -----Original Message-----
> From: Jason Andryuk <jandryuk@gmail.com>
> Sent: 24 June 2020 13:20
> To: Stefano Stabellini <sstabellini@kernel.org>; Anthony Perard <anthony.perard@citrix.com>; Paul
> Durrant <paul@xen.org>; xen-devel@lists.xenproject.org
> Cc: Jason Andryuk <jandryuk@gmail.com>; qemu-devel@nongnu.org
> Subject: [PATCH] xen: Fix xen-legacy-backend qdev types
> 
> xen-sysdev is a TYPE_SYS_BUS_DEVICE.  bus_type should not be changed so
> that it can plug into the System bus.  Otherwise this assert triggers:
> qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
> `dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
> failed.
> 
> TYPE_XENBACKEND attaches to TYPE_XENSYSBUS, so its class_init needs to
> be set accordingly to attach the qdev.  Otherwise the following assert
> triggers:
> qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
> `dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
> failed.
> 
> TYPE_XENBACKEND is not a subclass of XEN_XENSYSDEV, so it's parent
> is just TYPE_DEVICE.  Change that.
> 
> Signed-off-by: Jason Andryuk <jandryuk@gmail.com>

Clearly we raced. This patch and my patch #1 are identical so I'm happy to give my ack to this.

  Paul

> ---
>  hw/xen/xen-legacy-backend.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c
> index 2335ee2e65..c5c75c0064 100644
> --- a/hw/xen/xen-legacy-backend.c
> +++ b/hw/xen/xen-legacy-backend.c
> @@ -789,11 +789,12 @@ static void xendev_class_init(ObjectClass *klass, void *data)
>      set_bit(DEVICE_CATEGORY_MISC, dc->categories);
>      /* xen-backend devices can be plugged/unplugged dynamically */
>      dc->user_creatable = true;
> +    dc->bus_type = TYPE_XENSYSBUS;
>  }
> 
>  static const TypeInfo xendev_type_info = {
>      .name          = TYPE_XENBACKEND,
> -    .parent        = TYPE_XENSYSDEV,
> +    .parent        = TYPE_DEVICE,
>      .class_init    = xendev_class_init,
>      .instance_size = sizeof(struct XenLegacyDevice),
>  };
> @@ -824,7 +825,6 @@ static void xen_sysdev_class_init(ObjectClass *klass, void *data)
>      DeviceClass *dc = DEVICE_CLASS(klass);
> 
>      device_class_set_props(dc, xen_sysdev_properties);
> -    dc->bus_type = TYPE_XENSYSBUS;
>  }
> 
>  static const TypeInfo xensysdev_info = {
> --
> 2.25.1

Re: [PATCH] xen: Fix xen-legacy-backend qdev types

Posted by Jason Andryuk 5 years, 4 months ago

On Wed, Jun 24, 2020 at 8:30 AM Paul Durrant <xadimgnik@gmail.com> wrote:
>
> > -----Original Message-----
> > From: Jason Andryuk <jandryuk@gmail.com>
> > Sent: 24 June 2020 13:20
> > To: Stefano Stabellini <sstabellini@kernel.org>; Anthony Perard <anthony.perard@citrix.com>; Paul
> > Durrant <paul@xen.org>; xen-devel@lists.xenproject.org
> > Cc: Jason Andryuk <jandryuk@gmail.com>; qemu-devel@nongnu.org
> > Subject: [PATCH] xen: Fix xen-legacy-backend qdev types
> >
> > xen-sysdev is a TYPE_SYS_BUS_DEVICE.  bus_type should not be changed so
> > that it can plug into the System bus.  Otherwise this assert triggers:
> > qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
> > `dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
> > failed.
> >
> > TYPE_XENBACKEND attaches to TYPE_XENSYSBUS, so its class_init needs to
> > be set accordingly to attach the qdev.  Otherwise the following assert
> > triggers:
> > qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
> > `dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
> > failed.
> >
> > TYPE_XENBACKEND is not a subclass of XEN_XENSYSDEV, so it's parent
> > is just TYPE_DEVICE.  Change that.
> >
> > Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
>
> Clearly we raced. This patch and my patch #1 are identical so I'm happy to give my ack to this.

Yeah, looks like you beat me by a hair :)

Either way it gets fixed is fine by me.

Thanks,
Jason

Re: [PATCH] xen: Fix xen-legacy-backend qdev types

Posted by Anthony PERARD 5 years, 4 months ago

On Wed, Jun 24, 2020 at 08:52:44AM -0400, Jason Andryuk wrote:
> On Wed, Jun 24, 2020 at 8:30 AM Paul Durrant <xadimgnik@gmail.com> wrote:
> >
> > > -----Original Message-----
> > > From: Jason Andryuk <jandryuk@gmail.com>
> > > Sent: 24 June 2020 13:20
> > > To: Stefano Stabellini <sstabellini@kernel.org>; Anthony Perard <anthony.perard@citrix.com>; Paul
> > > Durrant <paul@xen.org>; xen-devel@lists.xenproject.org
> > > Cc: Jason Andryuk <jandryuk@gmail.com>; qemu-devel@nongnu.org
> > > Subject: [PATCH] xen: Fix xen-legacy-backend qdev types
> > >
> > > xen-sysdev is a TYPE_SYS_BUS_DEVICE.  bus_type should not be changed so
> > > that it can plug into the System bus.  Otherwise this assert triggers:
> > > qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
> > > `dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
> > > failed.
> > >
> > > TYPE_XENBACKEND attaches to TYPE_XENSYSBUS, so its class_init needs to
> > > be set accordingly to attach the qdev.  Otherwise the following assert
> > > triggers:
> > > qemu-system-i386: hw/core/qdev.c:102: qdev_set_parent_bus: Assertion
> > > `dc->bus_type && object_dynamic_cast(OBJECT(bus), dc->bus_type)'
> > > failed.
> > >
> > > TYPE_XENBACKEND is not a subclass of XEN_XENSYSDEV, so it's parent
> > > is just TYPE_DEVICE.  Change that.
> > >
> > > Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
> >
> > Clearly we raced. This patch and my patch #1 are identical so I'm happy to give my ack to this.
> 
> Yeah, looks like you beat me by a hair :)
> 
> Either way it gets fixed is fine by me.

Since there's a choice to make, I think I'll take this patch, but I will
add:
Fixes: 81cb05732efb ("qdev: Assert devices are plugged into a bus that can take them")

Thanks,

-- 
Anthony PERARD