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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-07-04 01:02:25 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-07-04 01:02:25 +0200 |
commit | 5fc835284d45a10a181b5c3f149a701e0391d1b2 (patch) | |
tree | 2943c1dad48bf9281d206a2c3283500a51ebfb7e /drivers/net/macvtap.c | |
parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebi... (diff) | |
parent | virtio-pci: alloc only resources actually used. (diff) | |
download | linux-5fc835284d45a10a181b5c3f149a701e0391d1b2.tar.xz linux-5fc835284d45a10a181b5c3f149a701e0391d1b2.zip |
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/net/macvtap.c')
-rw-r--r-- | drivers/net/macvtap.c | 65 |
1 files changed, 63 insertions, 2 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 6a64197f5bce..f8370808a018 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -48,15 +48,70 @@ struct macvtap_queue { #define MACVTAP_FEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE) #define MACVTAP_VNET_LE 0x80000000 +#define MACVTAP_VNET_BE 0x40000000 + +#ifdef CONFIG_TUN_VNET_CROSS_LE +static inline bool macvtap_legacy_is_little_endian(struct macvtap_queue *q) +{ + return q->flags & MACVTAP_VNET_BE ? false : + virtio_legacy_is_little_endian(); +} + +static long macvtap_get_vnet_be(struct macvtap_queue *q, int __user *sp) +{ + int s = !!(q->flags & MACVTAP_VNET_BE); + + if (put_user(s, sp)) + return -EFAULT; + + return 0; +} + +static long macvtap_set_vnet_be(struct macvtap_queue *q, int __user *sp) +{ + int s; + + if (get_user(s, sp)) + return -EFAULT; + + if (s) + q->flags |= MACVTAP_VNET_BE; + else + q->flags &= ~MACVTAP_VNET_BE; + + return 0; +} +#else +static inline bool macvtap_legacy_is_little_endian(struct macvtap_queue *q) +{ + return virtio_legacy_is_little_endian(); +} + +static long macvtap_get_vnet_be(struct macvtap_queue *q, int __user *argp) +{ + return -EINVAL; +} + +static long macvtap_set_vnet_be(struct macvtap_queue *q, int __user *argp) +{ + return -EINVAL; +} +#endif /* CONFIG_TUN_VNET_CROSS_LE */ + +static inline bool macvtap_is_little_endian(struct macvtap_queue *q) +{ + return q->flags & MACVTAP_VNET_LE || + macvtap_legacy_is_little_endian(q); +} static inline u16 macvtap16_to_cpu(struct macvtap_queue *q, __virtio16 val) { - return __virtio16_to_cpu(q->flags & MACVTAP_VNET_LE, val); + return __virtio16_to_cpu(macvtap_is_little_endian(q), val); } static inline __virtio16 cpu_to_macvtap16(struct macvtap_queue *q, u16 val) { - return __cpu_to_virtio16(q->flags & MACVTAP_VNET_LE, val); + return __cpu_to_virtio16(macvtap_is_little_endian(q), val); } static struct proto macvtap_proto = { @@ -1085,6 +1140,12 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd, q->flags &= ~MACVTAP_VNET_LE; return 0; + case TUNGETVNETBE: + return macvtap_get_vnet_be(q, sp); + + case TUNSETVNETBE: + return macvtap_set_vnet_be(q, sp); + case TUNSETOFFLOAD: /* let the user check for future flags */ if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | |