Re: [for-4.15][PATCH v2 2/5] xen/iommu: Check if the IOMMU was initialized before tearing down

[Julien Grall <julien@xxxxxxx>]

Hi Paul,

On 09/02/2021 20:22, Paul Durrant wrote:
> > -----Original Message-----
> > From: Julien Grall <julien@xxxxxxx>
> > Sent: 09 February 2021 15:28
> > To: xen-devel@xxxxxxxxxxxxxxxxxxxx
> > Cc: hongyxia@xxxxxxxxxxxx; iwj@xxxxxxxxxxxxxx; Julien Grall 
> > <jgrall@xxxxxxxxxx>; Jan Beulich
> > <jbeulich@xxxxxxxx>; Paul Durrant <paul@xxxxxxx>
> > Subject: [for-4.15][PATCH v2 2/5] xen/iommu: Check if the IOMMU was initialized 
> > before tearing down
> >
> > From: Julien Grall <jgrall@xxxxxxxxxx>
> >
> > is_iommu_enabled() will return true even if the IOMMU has not been
> > initialized (e.g. the ops are not set).
> >
> > In the case of an early failure in arch_domain_init(), the function
> > iommu_destroy_domain() will be called even if the IOMMU is not
> > initialized.
> >
> > This will result to dereference the ops which will be NULL and an host
> > crash.
> >
> > Fix the issue by checking that ops has been set before accessing it.
> >
> > Fixes: 71e617a6b8f6 ("use is_iommu_enabled() where appropriate...")
> > Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
> Reviewed-by: Paul Durrant <paul@xxxxxxx>
Thanks! Ian gave his Release-Acked-by so I will commit this patch now.

Cheers,

--
Julien Grall