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Date: Thu, 27 Aug 2015 10:58:57 +0530
From: Bharata B Rao <bharata@linux.vnet.ibm.com>
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Subject: Re: [Qemu-devel] [FIX PATCH] spapr_rtas: Prevent QEMU crash during
 hotplug without a prior device_add
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To: Michael Roth <mdroth@linux.vnet.ibm.com>
Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, david@gibson.dropbear.id.au

On Wed, Aug 26, 2015 at 09:17:09AM -0500, Michael Roth wrote:
> Quoting Bharata B Rao (2015-08-25 23:04:11)
> > If drmgr is used in the guest to hotplug a device before a device_add
> > has been issued via the QEMU monitor, QEMU segfaults in configure_connector
> > call. This occurs due to accessing of NULL FDT which otherwise would have
> > been created and associated with the DRC during device_add command.
> > 
> > Check for NULL FDT and return failure from configure_connector call.
> > 
> > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> > Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
> 
> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> 
> > ---
> > Not fully sure if RTAS_OUT_HW_ERROR is the right error code here. Should
> > we be using RTAS_OUT_NOT_SUPPORTED instead ?

Based on my reading of PAPR+ 2.7, it appears that we should return -9003
error code here.

I am planning to add

#define SPAPR_DR_CC_RESPONSE_NOT_CONFIGURABLE -9003

and use it when fdt is NULL in ibm,configure-connector call. Is that fine ?

Regards,
Bharata.