[PATCH 2/7] rust: move VMState from bql to migration

[Paolo Bonzini <pbonzini@redhat.com>]

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.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 rust/Cargo.lock               | 4 +---
 rust/bql/Cargo.toml           | 3 ---
 rust/bql/meson.build          | 1 -
 rust/bql/src/cell.rs          | 6 ------
 rust/meson.build              | 2 +-
 rust/migration/Cargo.toml     | 1 +
 rust/migration/meson.build    | 4 ++--
 rust/migration/src/vmstate.rs | 2 ++
 8 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index 2826c4d027b..960f603cedb 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -57,9 +57,6 @@ dependencies = [
 [[package]]
 name = "bql"
 version = "0.1.0"
-dependencies = [
- "migration",
-]
 
 [[package]]
 name = "chardev"
@@ -141,6 +138,7 @@ checksum = "18d287de67fe55fd7e1581fe933d965a5a9477b38e949cfa9f8574ef01506398"
 name = "migration"
 version = "0.1.0"
 dependencies = [
+ "bql",
  "common",
  "util",
 ]
diff --git a/rust/bql/Cargo.toml b/rust/bql/Cargo.toml
index 1041bd4ea93..d87edf4c302 100644
--- a/rust/bql/Cargo.toml
+++ b/rust/bql/Cargo.toml
@@ -12,9 +12,6 @@ license.workspace = true
 repository.workspace = true
 rust-version.workspace = true
 
-[dependencies]
-migration = { path = "../migration" }
-
 [features]
 default = ["debug_cell"]
 debug_cell = []
diff --git a/rust/bql/meson.build b/rust/bql/meson.build
index 7214d944089..305d7111897 100644
--- a/rust/bql/meson.build
+++ b/rust/bql/meson.build
@@ -36,7 +36,6 @@ _bql_rs = static_library(
   override_options: ['rust_std=2021', 'build.rust_std=2021'],
   rust_abi: 'rust',
   rust_args: _bql_cfg,
-  link_with: [_migration_rs],
 )
 
 bql_rs = declare_dependency(link_with: [_bql_rs],
diff --git a/rust/bql/src/cell.rs b/rust/bql/src/cell.rs
index 8a0c8c14ad4..defa45a3294 100644
--- a/rust/bql/src/cell.rs
+++ b/rust/bql/src/cell.rs
@@ -151,8 +151,6 @@
     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 @@ pub fn take(&self) -> 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.
 ///
@@ -693,8 +689,6 @@ fn from(t: T) -> BqlRefCell<T> {
     }
 }
 
-impl_vmstate_transparent!(crate::cell::BqlRefCell<T> where T: VMState);
-
 struct BorrowRef<'b> {
     borrow: &'b Cell<BorrowFlag>,
 }
diff --git a/rust/meson.build b/rust/meson.build
index 0bb2a9630a1..f4fb7daf05a 100644
--- a/rust/meson.build
+++ b/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')
diff --git a/rust/migration/Cargo.toml b/rust/migration/Cargo.toml
index 708bfaaa682..f4a86275152 100644
--- a/rust/migration/Cargo.toml
+++ b/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" }
 
diff --git a/rust/migration/meson.build b/rust/migration/meson.build
index 2a49bd1633e..2f38da9220f 100644
--- a/rust/migration/meson.build
+++ b/rust/migration/meson.build
@@ -36,12 +36,12 @@ _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],
 )
 
 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
diff --git a/rust/migration/src/vmstate.rs b/rust/migration/src/vmstate.rs
index e04b19b3c9f..05a833a8b7d 100644
--- a/rust/migration/src/vmstate.rs
+++ b/rust/migration/src/vmstate.rs
@@ -275,6 +275,8 @@ unsafe impl<$base> $crate::vmstate::VMState for $type where $base: $crate::vmsta
     };
 }
 
+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);
-- 
2.51.0