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| author | Michael S. Tsirkin <mst@redhat.com> | 2015-10-27 11:37:39 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-10-27 20:17:03 -0700 |
| commit | e407f39afdc0741dcf20aed100b8e738ccab7cb1 (patch) | |
| tree | 3680ff97392f87e86e110da56d12bae323e5a638 /drivers/vhost | |
| parent | 85ff8a43f39fa6d2f970b5e1e5c03df87abde242 (diff) | |
| download | linux-e407f39afdc0741dcf20aed100b8e738ccab7cb1.tar.gz linux-e407f39afdc0741dcf20aed100b8e738ccab7cb1.tar.bz2 linux-e407f39afdc0741dcf20aed100b8e738ccab7cb1.zip | |
vhost: fix performance on LE hosts
commit 2751c9882b947292fcfb084c4f604e01724af804 ("vhost: cross-endian
support for legacy devices") introduced a minor regression: even with
cross-endian disabled, and even on LE host, vhost_is_little_endian is
checking is_le flag so there's always a branch.
To fix, simply check virtio_legacy_is_little_endian first.
Cc: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/vhost.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 4772862b71a7..d3f767448a72 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -183,10 +183,17 @@ static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) return vq->acked_features & (1ULL << bit); } +#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) { return vq->is_le; } +#else +static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) +{ + return virtio_legacy_is_little_endian() || vq->is_le; +} +#endif /* Memory accessors */ static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) |