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authorGreg Kurz <gkurz@linux.vnet.ibm.com>2015-04-24 14:26:24 +0200
committerMichael S. Tsirkin <mst@redhat.com>2015-06-01 15:48:54 +0200
commit7d82410950aa74adccf035c332e409af2bb93e92 (patch)
treeff910c555820a2bf0fbd7b17231fa75d0cea5427
parentab27c07f607253f928cbc8c64d9c0d273df09e6b (diff)
virtio: add explicit big-endian support to memory accessors
The current memory accessors logic is: - little endian if little_endian - native endian (i.e. no byteswap) if !little_endian If we want to fully support cross-endian vhost, we also need to be able to convert to big endian. Instead of changing the little_endian argument to some 3-value enum, this patch changes the logic to: - little endian if little_endian - big endian if !little_endian The native endian case is handled by all users with a trivial helper. This patch doesn't change any functionality, nor it does add overhead. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
-rw-r--r--drivers/net/macvtap.c3
-rw-r--r--drivers/net/tun.c3
-rw-r--r--drivers/vhost/vhost.h3
-rw-r--r--include/linux/virtio_byteorder.h24
-rw-r--r--include/linux/virtio_config.h3
-rw-r--r--include/linux/vringh.h3
6 files changed, 24 insertions, 15 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 4fdb88102082..072ccbaf7c45 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -51,7 +51,8 @@ struct macvtap_queue {
static inline bool macvtap_is_little_endian(struct macvtap_queue *q)
{
- return q->flags & MACVTAP_VNET_LE;
+ return q->flags & MACVTAP_VNET_LE ||
+ virtio_legacy_is_little_endian();
}
static inline u16 macvtap16_to_cpu(struct macvtap_queue *q, __virtio16 val)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 301e87c89a9f..b210139bef8f 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -208,7 +208,8 @@ struct tun_struct {
static inline bool tun_is_little_endian(struct tun_struct *tun)
{
- return tun->flags & TUN_VNET_LE;
+ return tun->flags & TUN_VNET_LE ||
+ virtio_legacy_is_little_endian();
}
static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 6a499603d856..a4fa33a79bf2 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -175,7 +175,8 @@ static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
{
- return vhost_has_feature(vq, VIRTIO_F_VERSION_1);
+ return vhost_has_feature(vq, VIRTIO_F_VERSION_1) ||
+ virtio_legacy_is_little_endian();
}
/* Memory accessors */
diff --git a/include/linux/virtio_byteorder.h b/include/linux/virtio_byteorder.h
index 51865d05b267..ce63a2c3a612 100644
--- a/include/linux/virtio_byteorder.h
+++ b/include/linux/virtio_byteorder.h
@@ -3,17 +3,21 @@
#include <linux/types.h>
#include <uapi/linux/virtio_types.h>
-/*
- * Low-level memory accessors for handling virtio in modern little endian and in
- * compatibility native endian format.
- */
+static inline bool virtio_legacy_is_little_endian(void)
+{
+#ifdef __LITTLE_ENDIAN
+ return true;
+#else
+ return false;
+#endif
+}
static inline u16 __virtio16_to_cpu(bool little_endian, __virtio16 val)
{
if (little_endian)
return le16_to_cpu((__force __le16)val);
else
- return (__force u16)val;
+ return be16_to_cpu((__force __be16)val);
}
static inline __virtio16 __cpu_to_virtio16(bool little_endian, u16 val)
@@ -21,7 +25,7 @@ static inline __virtio16 __cpu_to_virtio16(bool little_endian, u16 val)
if (little_endian)
return (__force __virtio16)cpu_to_le16(val);
else
- return (__force __virtio16)val;
+ return (__force __virtio16)cpu_to_be16(val);
}
static inline u32 __virtio32_to_cpu(bool little_endian, __virtio32 val)
@@ -29,7 +33,7 @@ static inline u32 __virtio32_to_cpu(bool little_endian, __virtio32 val)
if (little_endian)
return le32_to_cpu((__force __le32)val);
else
- return (__force u32)val;
+ return be32_to_cpu((__force __be32)val);
}
static inline __virtio32 __cpu_to_virtio32(bool little_endian, u32 val)
@@ -37,7 +41,7 @@ static inline __virtio32 __cpu_to_virtio32(bool little_endian, u32 val)
if (little_endian)
return (__force __virtio32)cpu_to_le32(val);
else
- return (__force __virtio32)val;
+ return (__force __virtio32)cpu_to_be32(val);
}
static inline u64 __virtio64_to_cpu(bool little_endian, __virtio64 val)
@@ -45,7 +49,7 @@ static inline u64 __virtio64_to_cpu(bool little_endian, __virtio64 val)
if (little_endian)
return le64_to_cpu((__force __le64)val);
else
- return (__force u64)val;
+ return be64_to_cpu((__force __be64)val);
}
static inline __virtio64 __cpu_to_virtio64(bool little_endian, u64 val)
@@ -53,7 +57,7 @@ static inline __virtio64 __cpu_to_virtio64(bool little_endian, u64 val)
if (little_endian)
return (__force __virtio64)cpu_to_le64(val);
else
- return (__force __virtio64)val;
+ return (__force __virtio64)cpu_to_be64(val);
}
#endif /* _LINUX_VIRTIO_BYTEORDER */
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 170947eb11b5..e5ce8ab0b8b0 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -207,7 +207,8 @@ int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
static inline bool virtio_is_little_endian(struct virtio_device *vdev)
{
- return virtio_has_feature(vdev, VIRTIO_F_VERSION_1);
+ return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
+ virtio_legacy_is_little_endian();
}
/* Memory accessors */
diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 3ed62efc2bc5..bc6c28d04263 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -228,7 +228,8 @@ static inline void vringh_notify(struct vringh *vrh)
static inline bool vringh_is_little_endian(const struct vringh *vrh)
{
- return vrh->little_endian;
+ return vrh->little_endian ||
+ virtio_legacy_is_little_endian();
}
static inline u16 vringh16_to_cpu(const struct vringh *vrh, __virtio16 val)