Messages in this thread | | | Subject | Re: [PATCH v2 1/1] s390: virtio: let arch accept devices without IOMMU feature | From | Pierre Morel <> | Date | Tue, 16 Jun 2020 09:35:19 +0200 |
| |
On 2020-06-16 08:55, Christian Borntraeger wrote: > > > On 15.06.20 14:39, Pierre Morel wrote: >> An architecture protecting the guest memory against unauthorized host >> access may want to enforce VIRTIO I/O device protection through the >> use of VIRTIO_F_IOMMU_PLATFORM. >> >> Let's give a chance to the architecture to accept or not devices >> without VIRTIO_F_IOMMU_PLATFORM. >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> > > > Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Thanks,
> > Shouldnt we maybe add a pr_warn if that happens to help the admins to understand what is going on? > >
Yes, Connie asked for it too, good that you remind it to me, I add it.
Thanks, Pierre
>> --- >> arch/s390/mm/init.c | 6 ++++++ >> drivers/virtio/virtio.c | 9 +++++++++ >> include/linux/virtio.h | 2 ++ >> 3 files changed, 17 insertions(+) >> >> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c >> index 87b2d024e75a..3f04ad09650f 100644 >> --- a/arch/s390/mm/init.c >> +++ b/arch/s390/mm/init.c >> @@ -46,6 +46,7 @@ >> #include <asm/kasan.h> >> #include <asm/dma-mapping.h> >> #include <asm/uv.h> >> +#include <linux/virtio.h> >> >> pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir); >> >> @@ -162,6 +163,11 @@ bool force_dma_unencrypted(struct device *dev) >> return is_prot_virt_guest(); >> } >> >> +int arch_needs_iommu_platform(struct virtio_device *dev) >> +{ >> + return is_prot_virt_guest(); >> +} >> + >> /* protected virtualization */ >> static void pv_init(void) >> { >> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c >> index a977e32a88f2..30091089bee8 100644 >> --- a/drivers/virtio/virtio.c >> +++ b/drivers/virtio/virtio.c >> @@ -167,6 +167,11 @@ void virtio_add_status(struct virtio_device *dev, unsigned int status) >> } >> EXPORT_SYMBOL_GPL(virtio_add_status); >> >> +int __weak arch_needs_iommu_platform(struct virtio_device *dev) >> +{ >> + return 0; >> +} >> + >> int virtio_finalize_features(struct virtio_device *dev) >> { >> int ret = dev->config->finalize_features(dev); >> @@ -179,6 +184,10 @@ int virtio_finalize_features(struct virtio_device *dev) >> if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) >> return 0; >> >> + if (arch_needs_iommu_platform(dev) && >> + !virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) >> + return -EIO; >> + >> virtio_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK); >> status = dev->config->get_status(dev); >> if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) { >> diff --git a/include/linux/virtio.h b/include/linux/virtio.h >> index a493eac08393..2c46b310c38c 100644 >> --- a/include/linux/virtio.h >> +++ b/include/linux/virtio.h >> @@ -195,4 +195,6 @@ void unregister_virtio_driver(struct virtio_driver *drv); >> #define module_virtio_driver(__virtio_driver) \ >> module_driver(__virtio_driver, register_virtio_driver, \ >> unregister_virtio_driver) >> + >> +int arch_needs_iommu_platform(struct virtio_device *dev); >> #endif /* _LINUX_VIRTIO_H */ >>
-- Pierre Morel IBM Lab Boeblingen
| |