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| author | Pierre Morel <pmorel@linux.ibm.com> | 2020-09-10 10:53:49 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2020-10-21 10:34:12 -0400 |
| commit | 0afa15e1a5294754066343cad24af5ec8edae96d (patch) | |
| tree | 64e15eeb034e2bfb937aaf6def594750032712b8 | |
| parent | b9747fdf0c1dad088eb21d5191295999ae7b4b40 (diff) | |
| download | linux-0afa15e1a5294754066343cad24af5ec8edae96d.tar.gz linux-0afa15e1a5294754066343cad24af5ec8edae96d.tar.bz2 linux-0afa15e1a5294754066343cad24af5ec8edae96d.zip | |
virtio: let arch advertise guest's memory access restrictions
An architecture may restrict host access to guest memory,
e.g. IBM s390 Secure Execution or AMD SEV.
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
to 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_ACCESS_PLATFORM is required, but not set.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/1599728030-17085-2-git-send-email-pmorel@linux.ibm.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
| -rw-r--r-- | drivers/virtio/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/virtio/virtio.c | 15 | ||||
| -rw-r--r-- | include/linux/virtio_config.h | 10 |
3 files changed, 31 insertions, 0 deletions
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 5c92e4a50882..ef2d49430800 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 if the architecture may need to enforce + VIRTIO_F_ACCESS_PLATFORM + menuconfig VIRTIO_MENU bool "Virtio drivers" default y diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index a977e32a88f2..a2b3f12e10a2 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -176,6 +176,21 @@ int virtio_finalize_features(struct virtio_device *dev) if (ret) return ret; + ret = arch_has_restricted_virtio_memory_access(); + if (ret) { + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) { + dev_warn(&dev->dev, + "device must provide VIRTIO_F_VERSION_1\n"); + return -ENODEV; + } + + if (!virtio_has_feature(dev, VIRTIO_F_ACCESS_PLATFORM)) { + dev_warn(&dev->dev, + "device must provide VIRTIO_F_ACCESS_PLATFORM\n"); + return -ENODEV; + } + } + if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1)) return 0; diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 8fe857e27ef3..3f697c8c8205 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -540,4 +540,14 @@ static inline void virtio_cwrite64(struct virtio_device *vdev, virtio_cread_le((vdev), structname, member, ptr); \ _r; \ }) + +#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS +int arch_has_restricted_virtio_memory_access(void); +#else +static inline int arch_has_restricted_virtio_memory_access(void) +{ + return 0; +} +#endif /* CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS */ + #endif /* _LINUX_VIRTIO_CONFIG_H */ |