virtio-devices: move userspace mapping to vm-device

Move UserspaceMapping to vm-device to avoid redefinition since
UserspaceMapping is used by both `virtio-devices` and `device`
crate.

Signed-off-by: Songqian Li <sionli@tencent.com>

vm-device/Cargo.toml

@@ -14,4 +14,5 @@ hypervisor = { path = "../hypervisor" }
 serde = { workspace = true, features = ["derive", "rc"] }
 thiserror = { workspace = true }
 vfio-ioctls = { workspace = true, default-features = false }
+vm-memory = { workspace = true, features = ["backend-mmap"] }
 vmm-sys-util = { workspace = true }

vm-device/src/lib.rs

@@ -4,6 +4,7 @@
 //
 
 use serde::{Deserialize, Serialize};
+use vm_memory::{GuestAddress, GuestUsize};
 
 mod bus;
 pub mod dma_mapping;
@@ -58,3 +59,12 @@ pub enum Resource {
     /// KVM memslot index.
     KvmMemSlot(u32),
 }
+
+#[derive(Clone)]
+pub struct UserspaceMapping {
+    pub host_addr: u64,
+    pub mem_slot: u32,
+    pub addr: GuestAddress,
+    pub len: GuestUsize,
+    pub mergeable: bool,
+}