vduse: bump version number

Finalize the series by advertising VDUSE API v1 support to userspace.

Now that all required infrastructure for v1 (ASIDs, VQ groups,
update_iotlb_v2) is in place, VDUSE devices can opt in to the new
features.

Assume API version 0 if the VDUSE instance does not call
VDUSE_GET_API_VERSION to maintain compatibility.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260119143306.1818855-13-eperezma@redhat.com>

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 2727c0c26003f2a243534fadaefe4fc41dc9d112..73d1d517dc6c6b576e93e166eb3b9fa65a57afcd 100644 (file)
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -52,6 +52,15 @@
 
 #define IRQ_UNBOUND -1
 
+/*
+ * VDUSE instance have not asked the vduse API version, so assume 0.
+ *
+ * Old devices may not ask for the device version and assume it is 0.  Keep
+ * this value for these.  From the moment the VDUSE instance ask for the
+ * version, convert to the latests supported one and continue regular flow
+ */
+#define VDUSE_API_VERSION_NOT_ASKED U64_MAX
+
 struct vduse_virtqueue {
        u16 index;
        u16 num_max;
@@ -2153,6 +2162,8 @@ static long vduse_ioctl(struct file *file, unsigned int cmd,
        mutex_lock(&vduse_lock);
        switch (cmd) {
        case VDUSE_GET_API_VERSION:
+               if (control->api_version == VDUSE_API_VERSION_NOT_ASKED)
+                       control->api_version = VDUSE_API_VERSION_1;
                ret = put_user(control->api_version, (u64 __user *)argp);
                break;
        case VDUSE_SET_API_VERSION: {
@@ -2163,7 +2174,7 @@ static long vduse_ioctl(struct file *file, unsigned int cmd,
                        break;
 
                ret = -EINVAL;
-               if (api_version > VDUSE_API_VERSION)
+               if (api_version > VDUSE_API_VERSION_1)
                        break;
 
                ret = 0;
@@ -2180,6 +2191,8 @@ static long vduse_ioctl(struct file *file, unsigned int cmd,
                        break;
 
                ret = -EINVAL;
+               if (control->api_version == VDUSE_API_VERSION_NOT_ASKED)
+                       control->api_version = VDUSE_API_VERSION;
                if (!vduse_validate_config(&config, control->api_version))
                        break;
 
@@ -2230,7 +2243,7 @@ static int vduse_open(struct inode *inode, struct file *file)
        if (!control)
                return -ENOMEM;
 
-       control->api_version = VDUSE_API_VERSION;
+       control->api_version = VDUSE_API_VERSION_NOT_ASKED;
        file->private_data = control;
 
        return 0;