Linux Virtualization - Nov 2014 - [PATCH v4 25/42] vhost: add memory access wrappers

Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
 drivers/vhost/vhost.h | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 3eda654..b9032e8 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -174,6 +174,37 @@ enum {
 
 static inline int vhost_has_feature(struct vhost_virtqueue *vq, int bit)
 {
-	return vq->acked_features & (1 << bit);
+	return vq->acked_features & (1ULL << bit);
+}
+
+/* Memory accessors */
+static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
+{
+	return __virtio16_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
+{
+	return __cpu_to_virtio16(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
+{
+	return __virtio32_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
+{
+	return __cpu_to_virtio32(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
+{
+	return __virtio64_to_cpu(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
+{
+	return __cpu_to_virtio64(vhost_has_feature(vq, VIRTIO_F_VERSION_1), val);
 }
 #endif
-- 
MST

On Tue, 25 Nov 2014 18:43:10 +0200
"Michael S. Tsirkin" <mst at redhat.com> wrote:

"These wrappers are needed to handle virtio endianness conversions."

?
> Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> ---
>  drivers/vhost/vhost.h | 33 ++++++++++++++++++++++++++++++++-
>  1 file changed, 32 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index 3eda654..b9032e8 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -174,6 +174,37 @@ enum {
> 
>  static inline int vhost_has_feature(struct vhost_virtqueue *vq, int bit)
>  {
> -	return vq->acked_features & (1 << bit);
> +	return vq->acked_features & (1ULL << bit);
Should this hunk go into patch 28?
> +}

On Wed, Nov 26, 2014 at 02:54:38PM +0100, Cornelia Huck
wrote:
> On Tue, 25 Nov 2014 18:43:10 +0200
> "Michael S. Tsirkin" <mst at redhat.com> wrote:
> 
> "These wrappers are needed to handle virtio endianness
conversions."
> 
> ?
yes, it's same as virtio ones. I'll add this text, thanks.
> > Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> > ---
> >  drivers/vhost/vhost.h | 33 ++++++++++++++++++++++++++++++++-
> >  1 file changed, 32 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> > index 3eda654..b9032e8 100644
> > --- a/drivers/vhost/vhost.h
> > +++ b/drivers/vhost/vhost.h
> > @@ -174,6 +174,37 @@ enum {
> > 
> >  static inline int vhost_has_feature(struct vhost_virtqueue *vq, int
bit)
> >  {
> > -	return vq->acked_features & (1 << bit);
> > +	return vq->acked_features & (1ULL << bit);
> 
> Should this hunk go into patch 28?
Well, this is needed here since 1 << 32 is not legal C.

I can move it - this means patch 28 will have to move earlier
in series though.


> > +}