On 2020/7/15 下午9:58, Michael S. Tsirkin wrote:
VDPA sim stores config space as native endian, but that
is wrong: modern guests expect LE.
I coded up the following to fix it up, but it is wrong too:
vdpasim_create is called before guest features are known.
So what should we do? New ioctl to specify the interface used?
More ideas?
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Can we do the endian conversion in set_config/get_config()?
Thanks
---
drivers/vdpa/vdpa_sim/vdpa_sim.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index a9bc5e0fb353..cc754ae0ec15 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -24,6 +24,7 @@
#include <linux/etherdevice.h>
#include <linux/vringh.h>
#include <linux/vdpa.h>
+#include <linux/virtio_byteorder.h>
#include <linux/vhost_iotlb.h>
#include <uapi/linux/virtio_config.h>
#include <uapi/linux/virtio_net.h>
@@ -72,6 +73,23 @@ struct vdpasim {
u64 features;
};
+/* TODO: cross-endian support */
+static inline bool vdpasim_is_little_endian(struct vdpasim *vdpasim)
+{
+ return virtio_legacy_is_little_endian() ||
+ (vdpasim->features & (1ULL << VIRTIO_F_VERSION_1));
+}
+
+static inline u16 vdpasim16_to_cpu(struct vdpasim *vdpasim, __virtio16 val)
+{
+ return __virtio16_to_cpu(vdpasim_is_little_endian(vdpasim), val);
+}
+
+static inline __virtio16 cpu_to_vdpasim16(struct vdpasim *vdpasim, u16 val)
+{
+ return __cpu_to_virtio16(vdpasim_is_little_endian(vdpasim), val);
+}
+
static struct vdpasim *vdpasim_dev;
static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
@@ -332,8 +350,8 @@ static struct vdpasim *vdpasim_create(void)
goto err_iommu;
config = &vdpasim->config;
- config->mtu = 1500;
- config->status = VIRTIO_NET_S_LINK_UP;
+ config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
+ config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
eth_random_addr(config->mac);
vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu);
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
