Messages in this thread |  | | Subject | Re: [PATCH v5 2/2] s390: virtio: PV needs VIRTIO I/O device protection | From | Pierre Morel <> | Date | Thu, 9 Jul 2020 12:51:58 +0200 |
| |
On 2020-07-09 10:57, Cornelia Huck wrote: > On Thu, 9 Jul 2020 10:39:19 +0200 > Pierre Morel <pmorel@linux.ibm.com> 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 >> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> >> --- >> 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.
And I think easier to look for in case of debugging purpose. I change it if there is more demands.
> >> + return -ENODEV; >> + } >> + >> + return 0; >> +} >> + >> /* protected virtualization */ >> static void pv_init(void) >> { > > Either way, > > Reviewed-by: Cornelia Huck <cohuck@redhat.com> >
Thanks, Pierre
-- Pierre Morel IBM Lab Boeblingen
|  |