Re: [PATCH v9 1/2] virtio: let arch advertise guest's memory access restrictions

[Pierre Morel]

On 2020-08-21 13:59, Cornelia Huck wrote:
> On Wed, 19 Aug 2020 18:23:17 +0200
> Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
>
> > An architecture may restrict host access to guest memory.
>
> "e.g. IBM s390 Secure Execution or AMD SEV"
>
> Just to make clearer what you are referring to?

yes, thanks

> > Provide a new Kconfig entry the architecture can select,
> > CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
> > the arch_has_restricted_virtio_memory_access callback to advertise
>
> s/advertise/advertise to/

OK

> > VIRTIO common code when the architecture restricts memory access
> > from the host.
>
> "The common code can then fail the probe for any device where
> VIRTIO_F_IOMMU_PLATFORM is required, but not set."
>
> ?

Yes, better thanks

> > Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
> > ---
> >   drivers/virtio/Kconfig        |  6 ++++++
> >   drivers/virtio/virtio.c       | 15 +++++++++++++++
> >   include/linux/virtio_config.h |  9 +++++++++
> >   3 files changed, 30 insertions(+)
> >
> > diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> > index 5809e5f5b157..509f3b4d8ba1 100644
> > --- a/drivers/virtio/Kconfig
> > +++ b/drivers/virtio/Kconfig
> > @@ -6,6 +6,12 @@ config VIRTIO
> >   	  bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
> >   	  or CONFIG_S390_GUEST.
> >   
> > +config ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
> > +	bool
> > +	help
> > +	  This option is selected by any architecture enforcing
> > +	  VIRTIO_F_IOMMU_PLATFORM
>
> "This option is selected if the architecture may need to enforce
> VIRTIO_F_IOMMU_PLATFORM."
>
> ?

yes, better thanks

> > +
> >   menuconfig VIRTIO_MENU
> >   	bool "Virtio drivers"
> >   	default y
>
> (...)
>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>

I will make the rewordings.

Thanks,
Pierre

--
Pierre Morel
IBM Lab Boeblingen