On Thu, 9 Jul 2020 10:57:33 +0200
Cornelia Huck <cohuck@xxxxxxxxxx> wrote:
> On Thu, 9 Jul 2020 10:39:19 +0200
> Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
>
> > If protected virtualization is active on s390, the virtio queues are
> > not accessible to the host, unless VIRTIO_F_IOMMU_PLATFORM has been
> > negotiated. Use the new arch_validate_virtio_features() interface to
> > fail probe if that's not the case, preventing a host error on access
> > attempt
Punctuation at the end?
Also 'that's not the case' refers to the negation
'VIRTIO_F_IOMMU_PLATFORM has been negotiated',
arch_validate_virtio_features() is however part of
virtio_finalize_features(), which is in turn part of the feature
negotiation. But that is details. I'm fine with keeping the message as
is.
> >
> > Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
> > ---
> > arch/s390/mm/init.c | 27 +++++++++++++++++++++++++++
> > 1 file changed, 27 insertions(+)
> >
> > diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> > index 6dc7c3b60ef6..b8e6f90117da 100644
> > --- a/arch/s390/mm/init.c
> > +++ b/arch/s390/mm/init.c
> > @@ -45,6 +45,7 @@
> > #include <asm/kasan.h>
> > #include <asm/dma-mapping.h>
> > #include <asm/uv.h>
> > +#include <linux/virtio_config.h>
> >
> > pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
> >
> > @@ -161,6 +162,32 @@ bool force_dma_unencrypted(struct device *dev)
> > return is_prot_virt_guest();
> > }
> >
> > +/*
> > + * arch_validate_virtio_features
> > + * @dev: the VIRTIO device being added
> > + *
> > + * Return an error if required features are missing on a guest running
> > + * with protected virtualization.
> > + */
> > +int arch_validate_virtio_features(struct virtio_device *dev)
> > +{
> > + if (!is_prot_virt_guest())
> > + return 0;
> > +
> > + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
> > + dev_warn(&dev->dev, "device must provide VIRTIO_F_VERSION_1\n");
>
> I'd probably use "legacy virtio not supported with protected
> virtualization".
>
> > + return -ENODEV;
> > + }
> > +
> > + if (!virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) {
> > + dev_warn(&dev->dev,
> > + "device must provide VIRTIO_F_IOMMU_PLATFORM\n");
>
> "support for limited memory access required for protected
> virtualization"
>
> ?
>
> Mentioning the feature flag is shorter in both cases, though.
I liked the messages in v4. Why did we change those? Did somebody
complain?
I prefer the old ones, but it any case:
Acked-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
>
> > + return -ENODEV;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > /* protected virtualization */
> > static void pv_init(void)
> > {
>
> Either way,
>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
>
