rust: move VMState from bql to migration

The high-level wrapper Migratable<T> will contain a BqlCell,
which would introduce a circular dependency betwen the bql and
migration crates.  Move the implementation of VMState for cells
to "migration", together with the implementation for std types.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rust/Cargo.lock

@@ -59,7 +59,6 @@ name = "bql"
 version = "0.1.0"
 dependencies = [
  "glib-sys",
- "migration",
 ]
 
 [[package]]
@@ -198,6 +197,7 @@ checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
 name = "migration"
 version = "0.1.0"
 dependencies = [
+ "bql",
  "common",
  "glib-sys",
  "util",

rust/bql/Cargo.toml

@@ -13,7 +13,6 @@ repository.workspace = true
 rust-version.workspace = true
 
 [dependencies]
-migration = { path = "../migration" }
 glib-sys.workspace = true
 
 [features]

rust/bql/meson.build

@@ -37,7 +37,6 @@ _bql_rs = static_library(
   override_options: ['rust_std=2021', 'build.rust_std=2021'],
   rust_abi: 'rust',
   rust_args: _bql_cfg,
-  link_with: [_migration_rs],
   dependencies: [glib_sys_rs],
 )
 

rust/bql/src/cell.rs

@@ -151,8 +151,6 @@ use std::{
     ptr::NonNull,
 };
 
-use migration::impl_vmstate_transparent;
-
 /// A mutable memory location that is protected by the Big QEMU Lock.
 ///
 /// # Memory layout
@@ -364,8 +362,6 @@ impl<T: Default> BqlCell<T> {
     }
 }
 
-impl_vmstate_transparent!(crate::cell::BqlCell<T> where T: VMState);
-
 /// A mutable memory location with dynamically checked borrow rules,
 /// protected by the Big QEMU Lock.
 ///
@@ -691,8 +687,6 @@ impl<T> From<T> for BqlRefCell<T> {
     }
 }
 
-impl_vmstate_transparent!(crate::cell::BqlRefCell<T> where T: VMState);
-
 struct BorrowRef<'b> {
     borrow: &'b Cell<BorrowFlag>,
 }

rust/meson.build

@@ -29,8 +29,8 @@ subdir('qemu-macros')
 subdir('common')
 subdir('bits')
 subdir('util')
-subdir('migration')
 subdir('bql')
+subdir('migration')
 subdir('qom')
 subdir('system')
 subdir('chardev')

rust/migration/Cargo.toml

@@ -13,6 +13,7 @@ repository.workspace = true
 rust-version.workspace = true
 
 [dependencies]
+bql = { path = "../bql" }
 common = { path = "../common" }
 util = { path = "../util" }
 glib-sys.workspace = true

rust/migration/meson.build

@@ -37,12 +37,12 @@ _migration_rs = static_library(
   ),
   override_options: ['rust_std=2021', 'build.rust_std=2021'],
   rust_abi: 'rust',
-  link_with: [_util_rs],
+  link_with: [_util_rs, _bql_rs],
   dependencies: [common_rs, glib_sys_rs],
 )
 
 migration_rs = declare_dependency(link_with: [_migration_rs],
-  dependencies: [migration, qemuutil])
+  dependencies: [bql_rs, migration, qemuutil])
 
 # Doctests are essentially integration tests, so they need the same dependencies.
 # Note that running them requires the object files for C code, so place them

rust/migration/src/vmstate.rs

@@ -276,6 +276,8 @@ macro_rules! impl_vmstate_transparent {
     };
 }
 
+impl_vmstate_transparent!(bql::BqlCell<T> where T: VMState);
+impl_vmstate_transparent!(bql::BqlRefCell<T> where T: VMState);
 impl_vmstate_transparent!(std::cell::Cell<T> where T: VMState);
 impl_vmstate_transparent!(std::cell::UnsafeCell<T> where T: VMState);
 impl_vmstate_transparent!(std::pin::Pin<T> where T: VMState);