spapr_pci: fail gracefully with non-pseries machine types

[Qemu-devel] [PATCH] spapr_pci: fail gracefully with non-pseries machine types

Posted by Greg Kurz 6 years, 6 months ago

QEMU currently crashes when the user tries to add a spapr-pci-host-bridge
on a non-pseries machine:

$ qemu-system-ppc64 -M ppce500 -device spapr-pci-host-bridge,index=1
hw/ppc/spapr_pci.c:1535:spapr_phb_realize:
Object 0x1003dacae60 is not an instance of type spapr-machine
Aborted (core dumped)

The same thing happens with the deprecated but still available child type
spapr-pci-vfio-host-bridge.

Fix both by checking the machine type with object_dynamic_cast().

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 hw/ppc/spapr_pci.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 5049ced4e8b4..9e85106f51f8 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -1507,7 +1507,7 @@ static void spapr_pci_unplug_request(HotplugHandler *plug_handler,
 
 static void spapr_phb_realize(DeviceState *dev, Error **errp)
 {
-    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
+    sPAPRMachineState *spapr;
     SysBusDevice *s = SYS_BUS_DEVICE(dev);
     sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
     PCIHostState *phb = PCI_HOST_BRIDGE(s);
@@ -1519,6 +1519,12 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
     const unsigned windows_supported =
         sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
 
+    spapr = (sPAPRMachineState *) qdev_get_machine();
+    if (!object_dynamic_cast((Object *) spapr, TYPE_SPAPR_MACHINE)) {
+        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
+        return;
+    }
+
     if (sphb->index != (uint32_t)-1) {
         sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
         Error *local_err = NULL;

Re: [Qemu-devel] [Qemu-ppc] [PATCH] spapr_pci: fail gracefully with non-pseries machine types

Posted by Daniel Henrique Barboza 6 years, 6 months ago


On 10/06/2017 12:09 PM, Greg Kurz wrote:
> QEMU currently crashes when the user tries to add a spapr-pci-host-bridge
> on a non-pseries machine:
>
> $ qemu-system-ppc64 -M ppce500 -device spapr-pci-host-bridge,index=1
> hw/ppc/spapr_pci.c:1535:spapr_phb_realize:
> Object 0x1003dacae60 is not an instance of type spapr-machine
> Aborted (core dumped)
>
> The same thing happens with the deprecated but still available child type
> spapr-pci-vfio-host-bridge.
>
> Fix both by checking the machine type with object_dynamic_cast().
>
> Signed-off-by: Greg Kurz <groug@kaod.org>
> ---
Reviewed-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>

>   hw/ppc/spapr_pci.c |    8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 5049ced4e8b4..9e85106f51f8 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1507,7 +1507,7 @@ static void spapr_pci_unplug_request(HotplugHandler *plug_handler,
>
>   static void spapr_phb_realize(DeviceState *dev, Error **errp)
>   {
> -    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> +    sPAPRMachineState *spapr;
>       SysBusDevice *s = SYS_BUS_DEVICE(dev);
>       sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
>       PCIHostState *phb = PCI_HOST_BRIDGE(s);
> @@ -1519,6 +1519,12 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
>       const unsigned windows_supported =
>           sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
>
> +    spapr = (sPAPRMachineState *) qdev_get_machine();
> +    if (!object_dynamic_cast((Object *) spapr, TYPE_SPAPR_MACHINE)) {
> +        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
> +        return;
> +    }
> +
>       if (sphb->index != (uint32_t)-1) {
>           sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
>           Error *local_err = NULL;
>
>

Re: [Qemu-devel] [PATCH] spapr_pci: fail gracefully with non-pseries machine types

Posted by David Gibson 6 years, 6 months ago

On Fri, Oct 06, 2017 at 05:09:04PM +0200, Greg Kurz wrote:
> QEMU currently crashes when the user tries to add a spapr-pci-host-bridge
> on a non-pseries machine:
> 
> $ qemu-system-ppc64 -M ppce500 -device spapr-pci-host-bridge,index=1
> hw/ppc/spapr_pci.c:1535:spapr_phb_realize:
> Object 0x1003dacae60 is not an instance of type spapr-machine
> Aborted (core dumped)
> 
> The same thing happens with the deprecated but still available child type
> spapr-pci-vfio-host-bridge.
> 
> Fix both by checking the machine type with object_dynamic_cast().
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>



> ---
>  hw/ppc/spapr_pci.c |    8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 5049ced4e8b4..9e85106f51f8 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1507,7 +1507,7 @@ static void spapr_pci_unplug_request(HotplugHandler *plug_handler,
>  
>  static void spapr_phb_realize(DeviceState *dev, Error **errp)
>  {
> -    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> +    sPAPRMachineState *spapr;
>      SysBusDevice *s = SYS_BUS_DEVICE(dev);
>      sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
>      PCIHostState *phb = PCI_HOST_BRIDGE(s);
> @@ -1519,6 +1519,12 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
>      const unsigned windows_supported =
>          sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
>  
> +    spapr = (sPAPRMachineState *) qdev_get_machine();
> +    if (!object_dynamic_cast((Object *) spapr, TYPE_SPAPR_MACHINE)) {
> +        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
> +        return;
> +    }

This is slightly clunky.  You could instead use OBJECT_CHECK in the
initializer, then just if (!spapr) here.

> +
>      if (sphb->index != (uint32_t)-1) {
>          sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
>          Error *local_err = NULL;
> 


-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [Qemu-devel] [PATCH] spapr_pci: fail gracefully with non-pseries machine types

Posted by Greg Kurz 6 years, 6 months ago

On Sat, 7 Oct 2017 16:19:25 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:

> On Fri, Oct 06, 2017 at 05:09:04PM +0200, Greg Kurz wrote:
> > QEMU currently crashes when the user tries to add a spapr-pci-host-bridge
> > on a non-pseries machine:
> > 
> > $ qemu-system-ppc64 -M ppce500 -device spapr-pci-host-bridge,index=1
> > hw/ppc/spapr_pci.c:1535:spapr_phb_realize:
> > Object 0x1003dacae60 is not an instance of type spapr-machine
> > Aborted (core dumped)
> > 
> > The same thing happens with the deprecated but still available child type
> > spapr-pci-vfio-host-bridge.
> > 
> > Fix both by checking the machine type with object_dynamic_cast().
> > 
> > Signed-off-by: Greg Kurz <groug@kaod.org>  
> 
> 
> 
> > ---
> >  hw/ppc/spapr_pci.c |    8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> > index 5049ced4e8b4..9e85106f51f8 100644
> > --- a/hw/ppc/spapr_pci.c
> > +++ b/hw/ppc/spapr_pci.c
> > @@ -1507,7 +1507,7 @@ static void spapr_pci_unplug_request(HotplugHandler *plug_handler,
> >  
> >  static void spapr_phb_realize(DeviceState *dev, Error **errp)
> >  {
> > -    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> > +    sPAPRMachineState *spapr;
> >      SysBusDevice *s = SYS_BUS_DEVICE(dev);
> >      sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
> >      PCIHostState *phb = PCI_HOST_BRIDGE(s);
> > @@ -1519,6 +1519,12 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
> >      const unsigned windows_supported =
> >          sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
> >  
> > +    spapr = (sPAPRMachineState *) qdev_get_machine();
> > +    if (!object_dynamic_cast((Object *) spapr, TYPE_SPAPR_MACHINE)) {
> > +        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
> > +        return;
> > +    }  
> 
> This is slightly clunky.  You could instead use OBJECT_CHECK in the
> initializer, then just if (!spapr) here.
> 

Unless I'm missing something, OBJECT_CHECK() is precisely what we're
removing with this patch to avoid the runtime assert...

#define SPAPR_MACHINE(obj) \
    OBJECT_CHECK(sPAPRMachineState, (obj), TYPE_SPAPR_MACHINE)

> > +
> >      if (sphb->index != (uint32_t)-1) {
> >          sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
> >          Error *local_err = NULL;
> >   
> 
>

Re: [Qemu-devel] [Qemu-ppc] [PATCH] spapr_pci: fail gracefully with non-pseries machine types

Posted by Greg Kurz 6 years, 6 months ago

On Sat, 7 Oct 2017 10:06:00 +0200
Greg Kurz <groug@kaod.org> wrote:

> On Sat, 7 Oct 2017 16:19:25 +1100
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > On Fri, Oct 06, 2017 at 05:09:04PM +0200, Greg Kurz wrote:  
> > > QEMU currently crashes when the user tries to add a spapr-pci-host-bridge
> > > on a non-pseries machine:
> > > 
> > > $ qemu-system-ppc64 -M ppce500 -device spapr-pci-host-bridge,index=1
> > > hw/ppc/spapr_pci.c:1535:spapr_phb_realize:
> > > Object 0x1003dacae60 is not an instance of type spapr-machine
> > > Aborted (core dumped)
> > > 
> > > The same thing happens with the deprecated but still available child type
> > > spapr-pci-vfio-host-bridge.
> > > 
> > > Fix both by checking the machine type with object_dynamic_cast().
> > > 
> > > Signed-off-by: Greg Kurz <groug@kaod.org>    
> > 
> > 
> >   
> > > ---
> > >  hw/ppc/spapr_pci.c |    8 +++++++-
> > >  1 file changed, 7 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> > > index 5049ced4e8b4..9e85106f51f8 100644
> > > --- a/hw/ppc/spapr_pci.c
> > > +++ b/hw/ppc/spapr_pci.c
> > > @@ -1507,7 +1507,7 @@ static void spapr_pci_unplug_request(HotplugHandler *plug_handler,
> > >  
> > >  static void spapr_phb_realize(DeviceState *dev, Error **errp)
> > >  {
> > > -    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> > > +    sPAPRMachineState *spapr;
> > >      SysBusDevice *s = SYS_BUS_DEVICE(dev);
> > >      sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
> > >      PCIHostState *phb = PCI_HOST_BRIDGE(s);
> > > @@ -1519,6 +1519,12 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
> > >      const unsigned windows_supported =
> > >          sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
> > >  
> > > +    spapr = (sPAPRMachineState *) qdev_get_machine();
> > > +    if (!object_dynamic_cast((Object *) spapr, TYPE_SPAPR_MACHINE)) {
> > > +        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
> > > +        return;
> > > +    }    
> > 
> > This is slightly clunky.  You could instead use OBJECT_CHECK in the
> > initializer, then just if (!spapr) here.
> >   
> 
> Unless I'm missing something, OBJECT_CHECK() is precisely what we're
> removing with this patch to avoid the runtime assert...
> 
> #define SPAPR_MACHINE(obj) \
>     OBJECT_CHECK(sPAPRMachineState, (obj), TYPE_SPAPR_MACHINE)
> 

Since we already do this in spapr-cpu-core, I guess I'll hide the ugliness
in some macro. I'll send another patch.

> > > +
> > >      if (sphb->index != (uint32_t)-1) {
> > >          sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
> > >          Error *local_err = NULL;
> > >     
> > 
> >   
>

Re: [Qemu-devel] [PATCH] spapr_pci: fail gracefully with non-pseries machine types

Posted by Greg Kurz 6 years, 6 months ago

On Sat, 7 Oct 2017 16:19:25 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:

> On Fri, Oct 06, 2017 at 05:09:04PM +0200, Greg Kurz wrote:
> > QEMU currently crashes when the user tries to add a spapr-pci-host-bridge
> > on a non-pseries machine:
> > 
> > $ qemu-system-ppc64 -M ppce500 -device spapr-pci-host-bridge,index=1
> > hw/ppc/spapr_pci.c:1535:spapr_phb_realize:
> > Object 0x1003dacae60 is not an instance of type spapr-machine
> > Aborted (core dumped)
> > 
> > The same thing happens with the deprecated but still available child type
> > spapr-pci-vfio-host-bridge.
> > 
> > Fix both by checking the machine type with object_dynamic_cast().
> > 
> > Signed-off-by: Greg Kurz <groug@kaod.org>  
> 
> 
> 
> > ---
> >  hw/ppc/spapr_pci.c |    8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> > index 5049ced4e8b4..9e85106f51f8 100644
> > --- a/hw/ppc/spapr_pci.c
> > +++ b/hw/ppc/spapr_pci.c
> > @@ -1507,7 +1507,7 @@ static void spapr_pci_unplug_request(HotplugHandler *plug_handler,
> >  
> >  static void spapr_phb_realize(DeviceState *dev, Error **errp)
> >  {
> > -    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> > +    sPAPRMachineState *spapr;
> >      SysBusDevice *s = SYS_BUS_DEVICE(dev);
> >      sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
> >      PCIHostState *phb = PCI_HOST_BRIDGE(s);
> > @@ -1519,6 +1519,12 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
> >      const unsigned windows_supported =
> >          sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
> >  
> > +    spapr = (sPAPRMachineState *) qdev_get_machine();
> > +    if (!object_dynamic_cast((Object *) spapr, TYPE_SPAPR_MACHINE)) {
> > +        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
> > +        return;
> > +    }  
> 
> This is slightly clunky.  You could instead use OBJECT_CHECK in the
> initializer, then just if (!spapr) here.
> 

The negative review on v2 seem to indicate we have an agreement on using
object_dynamic_cast() explicitly. So we have two possibilities, either
the "clunky" v1, or possibly:

-    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
+    /* We don't use SPAPR_MACHINE() in order to exit gracefully if the user
+     * tries to add a PHB to a non-pseries machine.
+     */
+    sPAPRMachineState *spapr =
+        (sPAPRMachineState *) object_dynamic_cast(qdev_get_machine(),
+                                                  TYPE_SPAPR_MACHINE);
     SysBusDevice *s = SYS_BUS_DEVICE(dev);
     sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
     PCIHostState *phb = PCI_HOST_BRIDGE(s);
     char *namebuf;
     int i;
     PCIBus *bus;
     uint64_t msi_window_size = 4096;
     sPAPRTCETable *tcet;
     const unsigned windows_supported =
         sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
 
+    if (!spapr) {
+        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
+        return;
+    }
+

Which one do you prefer ? I'll also change spapr_cpu_core_realize()
if needed.

> > +
> >      if (sphb->index != (uint32_t)-1) {
> >          sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
> >          Error *local_err = NULL;
> >   
> 
>

Re: [Qemu-devel] [PATCH] spapr_pci: fail gracefully with non-pseries machine types

Posted by David Gibson 6 years, 6 months ago

On Wed, Oct 11, 2017 at 09:29:08AM +0200, Greg Kurz wrote:
> On Sat, 7 Oct 2017 16:19:25 +1100
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > On Fri, Oct 06, 2017 at 05:09:04PM +0200, Greg Kurz wrote:
> > > QEMU currently crashes when the user tries to add a spapr-pci-host-bridge
> > > on a non-pseries machine:
> > > 
> > > $ qemu-system-ppc64 -M ppce500 -device spapr-pci-host-bridge,index=1
> > > hw/ppc/spapr_pci.c:1535:spapr_phb_realize:
> > > Object 0x1003dacae60 is not an instance of type spapr-machine
> > > Aborted (core dumped)
> > > 
> > > The same thing happens with the deprecated but still available child type
> > > spapr-pci-vfio-host-bridge.
> > > 
> > > Fix both by checking the machine type with object_dynamic_cast().
> > > 
> > > Signed-off-by: Greg Kurz <groug@kaod.org>  
> > 
> > 
> > 
> > > ---
> > >  hw/ppc/spapr_pci.c |    8 +++++++-
> > >  1 file changed, 7 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> > > index 5049ced4e8b4..9e85106f51f8 100644
> > > --- a/hw/ppc/spapr_pci.c
> > > +++ b/hw/ppc/spapr_pci.c
> > > @@ -1507,7 +1507,7 @@ static void spapr_pci_unplug_request(HotplugHandler *plug_handler,
> > >  
> > >  static void spapr_phb_realize(DeviceState *dev, Error **errp)
> > >  {
> > > -    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> > > +    sPAPRMachineState *spapr;
> > >      SysBusDevice *s = SYS_BUS_DEVICE(dev);
> > >      sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
> > >      PCIHostState *phb = PCI_HOST_BRIDGE(s);
> > > @@ -1519,6 +1519,12 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
> > >      const unsigned windows_supported =
> > >          sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
> > >  
> > > +    spapr = (sPAPRMachineState *) qdev_get_machine();
> > > +    if (!object_dynamic_cast((Object *) spapr, TYPE_SPAPR_MACHINE)) {
> > > +        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
> > > +        return;
> > > +    }  
> > 
> > This is slightly clunky.  You could instead use OBJECT_CHECK in the
> > initializer, then just if (!spapr) here.
> > 
> 
> The negative review on v2 seem to indicate we have an agreement on using
> object_dynamic_cast() explicitly. So we have two possibilities, either
> the "clunky" v1, or possibly:
> 
> -    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> +    /* We don't use SPAPR_MACHINE() in order to exit gracefully if the user
> +     * tries to add a PHB to a non-pseries machine.
> +     */
> +    sPAPRMachineState *spapr =
> +        (sPAPRMachineState *) object_dynamic_cast(qdev_get_machine(),
> +                                                  TYPE_SPAPR_MACHINE);
>      SysBusDevice *s = SYS_BUS_DEVICE(dev);
>      sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
>      PCIHostState *phb = PCI_HOST_BRIDGE(s);
>      char *namebuf;
>      int i;
>      PCIBus *bus;
>      uint64_t msi_window_size = 4096;
>      sPAPRTCETable *tcet;
>      const unsigned windows_supported =
>          sphb->ddw_enabled ? SPAPR_PCI_DMA_MAX_WINDOWS : 1;
>  
> +    if (!spapr) {
> +        error_setg(errp, TYPE_SPAPR_PCI_HOST_BRIDGE " needs a pseries machine");
> +        return;
> +    }
> +
> 
> Which one do you prefer ? I'll also change spapr_cpu_core_realize()
> if needed.

Second one looks good to me.

> 
> > > +
> > >      if (sphb->index != (uint32_t)-1) {
> > >          sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
> > >          Error *local_err = NULL;
> > >   
> > 
> > 
> 



-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson