diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-07-03 16:02:25 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-07-03 16:02:25 -0700 |
commit | 5fc835284d45a10a181b5c3f149a701e0391d1b2 (patch) | |
tree | 2943c1dad48bf9281d206a2c3283500a51ebfb7e /drivers/vhost/Kconfig | |
parent | 0cbee992696236227a7ea411e4b0fbf73b918b6a (diff) | |
parent | 59a5b0f7bf74f88da6670bcbf924d8cc1e75b1ee (diff) |
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/vhost cross endian support from Michael Tsirkin:
"I have just queued some more bugfix patches today but none fix
regressions and none are related to these ones, so it looks like a
good time for a merge for -rc1.
The motivation for this is support for legacy BE guests on the new LE
hosts. There are two redeeming properties that made me merge this:
- It's a trivial amount of code: since we wrap host/guest accesses
anyway, almost all of it is well hidden from drivers.
- Sane platforms would never set flags like VHOST_CROSS_ENDIAN_LEGACY,
and when it's clear, there's zero overhead (as some point it was
tested by compiling with and without the patches, got the same
stripped binary).
Maybe we could create a Kconfig symbol to enforce the second point:
prevent people from enabling it eg on x86. I will look into this"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio-pci: alloc only resources actually used.
macvtap/tun: cross-endian support for little-endian hosts
vhost: cross-endian support for legacy devices
virtio: add explicit big-endian support to memory accessors
vhost: introduce vhost_is_little_endian() helper
vringh: introduce vringh_is_little_endian() helper
macvtap: introduce macvtap_is_little_endian() helper
tun: add tun_is_little_endian() helper
virtio: introduce virtio_is_little_endian() helper
Diffstat (limited to 'drivers/vhost/Kconfig')
-rw-r--r-- | drivers/vhost/Kconfig | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig index 017a1e8a8f6f..533eaf04f12f 100644 --- a/drivers/vhost/Kconfig +++ b/drivers/vhost/Kconfig @@ -32,3 +32,18 @@ config VHOST ---help--- This option is selected by any driver which needs to access the core of vhost. + +config VHOST_CROSS_ENDIAN_LEGACY + bool "Cross-endian support for vhost" + default n + ---help--- + This option allows vhost to support guests with a different byte + ordering from host while using legacy virtio. + + Userspace programs can control the feature using the + VHOST_SET_VRING_ENDIAN and VHOST_GET_VRING_ENDIAN ioctls. + + This is only useful on a few platforms (ppc64 and arm64). Since it + adds some overhead, it is disabled by default. + + If unsure, say "N". |